: Pics of coolant test of exhaust gas/head gasket leaking?



mnalep
07-14-10, 10:05 PM
I rented a kit to test for exhaust gas in the coolant from Autozone.

The kit came with a tube that is inserted in the coolant overflow, and blue liquid that is supposed to turn yellow within 2 minutes - if there are exhaust gasses present in the overflow tank - from a blown head gasket.

In my test the blue fluid got a bit lighter blue color, but did not turn yellow.

The pic below shows the test fluid before testing - it is a blue color:
http://img85.imageshack.us/img85/2357/230pn.jpg


The pic below is the test fluid after testing - it looks a lighter blue - not really yellow:
http://img85.imageshack.us/img85/3454/231sx.jpg

I tested with the same fluid, while the coolant was cold, warm, and hot - for at least 6 minutes.

It does not look yellow to me. What do you all think? Any experience with this test?

I did see a video on youtube.com, and the color they called yellow looked definitely a light yellow - a color very much like a light beer:

youtube.com/watch?v=QA7KVQq9vKA

youtube.com/watch?v=vgkMC-5Mtz8


Does this test show that I have no gasses in the coolant, or is this test inconclusive?

(I've been overheating up to 240 degrees. I put in new water pump(the old was leaking), a new thermostat, a new surge tank cap, I ran Prestone cleaner through the system, I burped the system, I had a flush/fill performed at Firestone AutoCare. And I'm still overheating)

My overheating testing - and logged my time, miles, speed, and temperature:

TIME MILES SPEED TEMP COMMENT
01:55 0 45 80 (Whatever outside temp was)
02:10 6 45 200
02:15 8 45 218
02:20 11 45 230
02:25 13 35 222 (Driving slower, about 35mph)
02:30 15 45 230 (Was at 45 for 5 minutes after 222)
02:35 17 45 240 (Stopped car, minor steam out cap)
02:24 17 0 225 (Car cooled down and I drove home)
02:50 18 35 230 (Parked in driveway and let it idle)
02:52 18 0 218 (Dropped while idleing to 218)
02:53 18 0 218 (I turned the A/C on)
02:54 18 0 220
02:55 18 0 220 (I pushed idle rpm up to 1500 rpm)
02:57 18 0 222 (I increased idle rpm to 2000 rpm)
02:58 18 0 222
02:59 18 0 230 (Shut car off, minor steam from cap)

What to try next? If I can rule out head gasket, I'll take the cooling system apart, but I don't know if I can rule out a leaky head gasket?

I have another thread on another board telling of my entire sage, but I can't post the link here as I am a new member.

Submariner409
07-15-10, 10:13 PM
What car, engine, year ???

The coolant gas test is OK.

Are we talking about a Northstar ??? Fans and relays/fuses OK ???

None of your temperatures indicate overheating.........

Fans run in SLOW any time any A/C function is called for. Fans go to SLOW at 224 degrees if A/C is OFF, FAST at 236 degrees.

You replaced the water pump. Even at 240 degrees there's no way you get steam out the reservoir cap unless the reservoir is grossly overfilled. At 16 (18 ?) psi the 50/50 coolant does not boil until 265 degrees. That reservoir should be halfway full, cold. NEVER check coolant levels hot.

mnalep
07-15-10, 11:02 PM
It is a 1997 Aurora, 4.0 Northstar engine.

Fans are working, both low and high speed good seem right where you indicate they should be.

The 230 - 240 temp is overheating. Temps of 210 - 220 are normal for my car. The red line on my gauge starts at just over 240. To me, this is overheating. At 240 I smell coolant, and see steam from my surge tank cap.

My cap is a 15psi cap, but is from Autozone. What temp would cause my 50/50 to boil given it's a 15 psi cap? (I did rent a pressure kit from AZ and someone said it might mess up threads on surge tank, so maybe cap is not locking on - although it seems to grab real tight).

I have been only adding coolant when the engine is cold, and keeping it no higher than the "FULL COLD" mark on the surge tank (about 1/2 full).

I was hoping to hear my block test indicated no head gasket leaks - so I am relieved to hear you think mine is OK.

I had a service tech at Firestone look at the car, and he says it is either a plugged up radiator, or a head gasket. He said he could not be sure, and he said I should spray wash the radiator at a car wash, and if that did not help that I should take the car to a dealer, or a radiator shop and let them inspect it.

Ranger
07-15-10, 11:25 PM
You could do a leak down test to test the head gaskets. See the Tech Tips section.

You didn't do the above test right after adding coolant, did you?

ibm4mad
07-16-10, 12:06 AM
It does not look yellow to me. ...

I looked at your picture. Rest assured that fluid does not look yellow by any stretch of my imagination. :histeric:

zonie77
07-16-10, 11:48 AM
Initial failure includes a loss in clamping force due to thread deterioration.That's a reduction, not a total loss. At idle and light cruise there is usually enough force to contain the combustion, as acceleration increases the clamping force becomes insufficient.

You should try a couple of hard acceleration runs, then do the test immediately.

Several people got positives if done this way.

I've never done the test myself but from what people have said the greenish tinge is suspect.

mnalep
07-16-10, 12:20 PM
Ranger, I will read that test.

The coolant was replaced a few days earlier, but I did top it off and drive a couple of times to get it mixed in and also thinking that would be enough to get gasses in the coolant - but maybe that is not enough time for the test kit to detect exhaust gas?

Zonie, if I do some hard acceleration runs, would I get big boil over if I took the surge tank cap off right afterward?

mnalep
07-16-10, 12:20 PM
Another note, I had it at Firestone for a diagnosis.

The mechanic there said it could either be the radiator is plugged, or that the head gasket is leaking. He suggested I hose out the radiator at a carwash and see if it helps, or take it to a radiator shop.

I have not tried spraying it down, I would need to take the radiator cover off, and loosen the fans to nudge them away from the rad so I could blast water out towards the front of the car, but will prob do that later.

But I called a radiator shop, and he doubts the rad is bad, as he said since it does not overheat at idle, it is prob not clogged or dirty! He suggested I remove the thermostat and drive it, and if does not overheat then that would tell me the head gasket was leaking. His reason was that exhaust gas in the coolant from a leak in the exhaust side would force the t'stat closed.

Necrosan
07-16-10, 12:29 PM
Uh, no.
Find a new mechanic RIGHT away.
(Firestone are NOT mechanics.)

mnalep
07-16-10, 01:01 PM
Necrosan, I'm confused by what your saying "no" about?

Submariner409
07-16-10, 01:42 PM
For starters, the thermostat in your cooling system is a necessary part of the coolant flow control - without a thermostat the system bypasses a LOT of coolant (far too much) coming from the heater circuit to the water pump.

The 4.0 has the same system as the 4.6, so here's the thermostat and housing, showing the difference from a "normal" single-ended thermostat.

mnalep
07-16-10, 02:25 PM
submariner,

So your saying the rad shop guy gave me bad advice, and I should not test the cooling system without the thermostat?

By "normal single ended thermostat", do you mean mine has flow to both the block, and the bypass to the surge tank?

BTW, The new thermostat I put in had a "wiggle valve" which is supposed to let gases escape past the thermostat, because the buildup of gases stop the t'stat from opening. Old t'stat did not have that wiggle valve.

What do you think the prob is?

mnalep
07-16-10, 02:57 PM
So I decided to test the coolant concentration. The tester said it was good to about -20, but I noticed 'particulate' matter in the coolant. I also too some pictures of the coolant in the tester, and in the surge tank to show the black 'specs' floating in the coolant, and on the surge tank.

Is this normal? Would this indicate bad head gaskets, or anything?


http://img710.imageshack.us/img710/3135/img2478e.jpg
http://img710.imageshack.us/img710/3135/img2478e.jpg

http://img710.imageshack.us/img710/6168/img2479eo.jpg
http://img710.imageshack.us/img710/6168/img2479eo.jpg


http://img710.imageshack.us/img710/3558/img2480t.jpg
http://img710.imageshack.us/img710/3558/img2480t.jpg

http://img710.imageshack.us/img710/5770/img2481c.jpg
http://img710.imageshack.us/img710/5770/img2481c.jpg


http://img710.imageshack.us/img710/4755/img2482c.jpg
http://img710.imageshack.us/img710/4755/img2482c.jpg


http://img693.imageshack.us/img693/1773/img2476y.jpg
http://img693.imageshack.us/img693/1773/img2476y.jpg

Submariner409
07-16-10, 03:01 PM
If your thermostat looks like the one in the picture, you're OK.

You should NEVER run a Northstar without a thermostat. - for the reasons stated and noted on the diagrams.

The coolant reservoir is a volume tank, nothing more. It uses a 3/4" line at the bottom to "float" on the cooling system, absorbing coolant expansion and contraction as temperatures change. The "purge line" is a constant slow bleed off the high point water pump housing, so that is a low-flow line which allows air and gas bubbles to escape into the airspace over the coolant, thus preventing bubbles in the coolant and subsequent water pump cavitation.

The little wiggle valve is also a bleeder - it prevents air bubbles from forming in the top of the lower radiator hose bends. Remember: coolant flows from the radiator INTO the thermostat, not OUT OF it.

Your black specks are probably the remains of the original GM sealant tablets installed at the factory to cure nuisance leaks in the field. GM has gotten away from installing those tablets - Bar's Leaks G12P (powder) or HDC tablets. (OR someone has gotten creative with some sort of sealant - that's a lot of crap floating around in that cylinder of coolant........) You might want to have a GM dealer do a coolant exchange using their vacuum machines.

I thought your car originally came with DEX-COOL installed.................Proper coolant concentration is about - 35 or so (??).

mnalep
07-16-10, 04:09 PM
My thermostat does look like the one pictured.

The picture with the particles floating in them is the coolant AFTER I had a power flush/fill done at Firestone. I guess I could flush it again.

I just got done spraying the radiator from behind with the garden hose. I removed the fans, and top radiator faceplate to get in there real close. It now needs to dry out. Not sure this will help, but it cost me just a few hours time.

I'm thinking about detaching the lower hose, and using the hose to push water through the radiator and out the top where the top hose connects.

I wish I knew what to fix?

STSS
07-16-10, 04:46 PM
That crap in your coolant might be from the firestone guys coolant flusher.... thats why everyone says to only get the coolant flushed (exchanged) at the dealer.... If not, just drain and refill.

mnalep
07-16-10, 05:09 PM
Oh, and it did come with Dexcool. I decided to switch to the Prestone universal when I swapped out the water pump.

Ranger
07-16-10, 10:18 PM
Ranger, I will read that test.

The coolant was replaced a few days earlier, but I did top it off and drive a couple of times to get it mixed in and also thinking that would be enough to get gasses in the coolant - but maybe that is not enough time for the test kit to detect exhaust gas?

Zonie, if I do some hard acceleration runs, would I get big boil over if I took the surge tank cap off right afterward?
The surge tank is not a high flow tank. Coolant does not constantly flow through it. You never want to test it soon after topping it off. That can give a false negative. The best time to test it is after one or more over heats with no recent top offs.

zonie77
07-18-10, 09:40 PM
I said to do a couple acceleration runs before testing coolant. When you have it warmed up do a fast run around the block, a couple blasts up to 40 should be enough. You should be able to leave the cap on loose for the run around the block. If it's blowing coolant out at that point it's almost sure to be HG's.

mnalep
07-20-10, 12:10 AM
Zonie, Ranger...Thanks. I'll try tomorrow. (I pulled radiator out today, and sprayed the radiator and the condensor off with a hose. I also flushed the radiator while it was out of the car - just to prove to myself that the water would flow though it well.

Submariner409
07-20-10, 10:21 AM
The new coolant fill will need to remain in the system for a few days - the coolant gas test depends on concentration, and the whole enchilada needs time to settle out..............

zonie77
07-20-10, 11:27 PM
The new coolant fill will need to remain in the system for a few days - the coolant gas test depends on concentration, and the whole enchilada needs time to settle out..............


Yes, as mentioned before, you need to drive it awhile with fresh coolant.

mnalep
07-21-10, 01:12 PM
Understood. I'll idle and drive several times before testing again, and I'll let you know how the test went. Thanks.

mnalep
07-21-10, 09:00 PM
I drove for over an hour today. With the A/C off, the temp was steady between about 225 and 230 - except for one time it went over 230.

But when I turned the A/C on - it climbed quickly to 240, within about 2-3 minutes. I turned the A/C off, and the temp dropped back to 225-230 in a few minutes of side street driving.

So it appears that flushing the radiator, and spraying the radiator and condensor off - has helped with the cooling.

I also am wondering if it is running cooler without the radiator top cover being on? (the black piece that covers the radiator and the condensor).

But driving with the A/C pushes the temp into the red zone. Is there anything else I can do?

I tested with the block test fluid, and it changed again to a light blue color, with a tinge of green - but not quite yellow. I'll drive more tomorrow and test again.

Ranger
07-21-10, 09:19 PM
I also am wondering if it is running cooler without the radiator top cover being on? (the black piece that covers the radiator and the condensor).
That should make it run hotter if anything. It gives the ram air someplace to escape rather than being forced through the radiator.


I tested with the block test fluid, and it changed again to a light blue color, with a tinge of green - but not quite yellow.
Sounds like the early stages of a head gasket failure.

mnalep
07-22-10, 09:39 AM
I will put the radiator cover back on, and if it aids in keeping the forced air going into the radiator, and engine running cooler, I'll be happy.

I forgot to mention, I also have a higher concentration of antifreeze now. When I removed the rad I lost about 4-5 quarts of liquid. when I put rad back on, i added about 3.5 quarts antifreeze and about 1 quart water. SO I am probably around 60% antifreeze and 40% water now.

I also was driving with the resonator off, so there was a 5inch round hole allowing air into the intake in addition to the air coming in through the air filter.

I also noticed a small amount of tear in the plastic air dam that forces the air towards the radiator/condensor coils. I am going to tape that up so no forced air leaks away from the radiator.

When I stopped for gas, the temp had been around 225. When I shut engine off the temp climbed to 240. I looked under the hood, and the surge tank was boiling and steaming off. If I really was at 240 - seems to me that I should not have been boiling coolant. I read that "A 50/50 mixture of water and ethylene glycol antifreeze in the cooling system will boil at 225 if the cap is open. But pressurizing the system with a spring-loaded cap raises the boiling temperature of the mix about 3 for every 1 psi of pressure. With a 15 psi cap, the boiling temperature will be up around 265 F." So I should not boil until over 265 with a 60/40 mix?

Would that water wetter product help much?

I am fearing head gasket starting to go also. But maybe the radiator is my problem, as it is running at normal temps longer now after cleaning it?

I had a oxygen sensor warning a while ago. This would not affect cooling would it? I read a car might run leaner, which would mean less gas, which would to me mean cooler rather than hotter if anything - since it's the burning of gas that produces the heat?

mnalep
07-22-10, 10:36 AM
Oops on the O2 sesnor comment above....

I read that " If the sensor dies altogether, the result can be a fixed, rich fuel mixture. Default on most fuel injected applications is mid-range after three minutes. This causes a big jump in fuel consumption as well as emissions. And if the converter overheats because of the rich mixture, it may suffer damage." Since burning produces heat - would more gas create more heat - might that be a reason for my overheating?

Ranger
07-22-10, 11:51 AM
When I stopped for gas, the temp had been around 225. When I shut engine off the temp climbed to 240. I looked under the hood, and the surge tank was boiling and steaming off. If I really was at 240 - seems to me that I should not have been boiling coolant. I read that "A 50/50 mixture of water and ethylene glycol antifreeze in the cooling system will boil at 225 if the cap is open. But pressurizing the system with a spring-loaded cap raises the boiling temperature of the mix about 3 for every 1 psi of pressure. With a 15 psi cap, the boiling temperature will be up around 265 F." So I should not boil until over 265 with a 60/40 mix?

Would that water wetter product help much?


Forget the "water wetter". It won't help.

What you saw was not boiling, but more likely "false boiling". It's exhaust gases being pumped into the cooling system via a breached head gasket, bubbling up in the tank and being vented via the cap. Not a good sign.

tateos
07-22-10, 05:33 PM
I agree with Ranger and Sub and Zonie

ejguillot
07-22-10, 06:31 PM
+1 on the above. Start getting the $$$ ready to pay for a headgasket repair (or buy the parts to do it yourself).

mnalep
07-26-10, 02:44 PM
If you're all correct, then I may as well stop playing with it.

I don't think I could handle drilling to install new bolts...so I'd have to find a repair shop locally. Anyone got recommendations for shop in Detroit, MI area? I'm in a western suburb, Redford. Any idea regarding price?

Anything I can do to nurse this car along if I don't do head gasket?

tateos
07-26-10, 03:07 PM
If you're in Detroit, then you're not too far from Jake's place, are you? I think most of us consider him to be the mother lode for HG repairs. And you are probably still in good enough shape to drive the car there, if you baby it a little.

http://www.northstarperformance.com/hg.php

zonie77
07-27-10, 01:49 AM
If you're in Detroit, then you're not too far from Jake's place, are you? I think most of us consider him to be the mother lode for HG repairs. And you are probably still in good enough shape to drive the car there, if you baby it a little.

http://www.northstarperformance.com/hg.php

I think Jake's is the best, unless you do it yourself. Nothing was rocket science! It was all standard stuff, just a long tedious job. Drilling the block wasn't hard, just a careful procedure. PM me if you want.

mnalep
07-27-10, 04:02 PM
Zonie- Thanks for the offer of advice - I may end up doing this!



I tested again, and got these results:


I tested again at idle - and logged my time, miles, speed, and temperature:



TIME MILES AVG. SPEED TEMP COMMENT
02:00 0 0 80 (87 degrees outside, car idling in driveway)
02:30 0 0 210
02:45 0 0 220
02:55 0 0 230 (at this time I turned the A/C on, and continued to idle it)
02:56 0 0 225 (temp coming down)
02:58 0 0 220
03:00 0 0 222
03:03 0 0 230
03:05 0 0 220 (temp coming down again)
03:15 0 0 225



So it basically idled for almost an hour with no overheating, and almost another 30 minutes with the A/C on - and no overheating - with the outside temp at 87 degrees.


I then tested again driving - and logged my time, miles, speed, and temperature:



TIME MILES AVG. SPEED TEMP COMMENT
09:40 0 0 100
09:53 6 45 200 (75 degrees outside, car driving an avg 45mph, stop and go traffic)
10:15 12 45 220
10:17 13 45 235
10:19 14 45 241 ( I stopped driving, pulled over and idled wit the hood up to cool off)
10:21 14 0 220
10:22 15 45 220 (I started driving again)
10:28 18 45 220
10:30 19 45 210
10:37 22 45 225
10:38 22 45 230
10:40 23 45 220
10:41 24 45 220 ( I continued driving and turned the A/C on)
10:45 26 45 240
10:46 26 45 250 ( I pulled over, idled, turned A/C off, and opened hood to cool off)
10:48 26 0 225 ( I started driving home. A/C off, after temp came down to 225)
10:50 26 0 220
10:55 29 45 220 ( I drove home and stopped driving)



I drove for almost 40 minutes before it jumped to 240. Again after drving with te A/C on it hit 240-250 in less than 5 minutes.

zonie77
07-27-10, 04:19 PM
Zonie- Thanks for the offer of advice - I may end up doing this!



I tested again, and got these results:


I tested again at idle - and logged my time, miles, speed, and temperature:



TIME MILES AVG. SPEED TEMP COMMENT
02:00 0 0 80 (87 degrees outside, car idling in driveway)
02:30 0 0 210
02:45 0 0 220
02:55 0 0 230 (at this time I turned the A/C on, and continued to idle it)
02:56 0 0 225 (temp coming down)
02:58 0 0 220
03 begin_of_the_skype_highlighting**************58 0 0 220 03******end_of_the_skype_highlighting:00 0 0 222
03:03 0 0 230
03:05 0 0 220 (temp coming down again)
03:15 0 0 225



So it basically idled for almost an hour with no overheating, and almost another 30 minutes with the A/C on - and no overheating - with the outside temp at 87 degrees.


I then tested again driving - and logged my time, miles, speed, and temperature:



TIME MILES AVG. SPEED TEMP COMMENT
09:40 0 0 100
09:53 6 45 200 (75 degrees outside, car driving an avg 45mph, stop and go traffic)
10:15 12 45 220
10:17 13 45 235
10:19 14 45 241 ( I stopped driving, pulled over and idled wit the hood up to cool off)
10:21 14 0 220
10:22 15 45 220 (I started driving again)
10:28 18 45 220
10:30 19 45 210
10:37 22 45 225
10:38 22 45 230
10:40 23 45 220
10:41 24 45 220 ( I continued driving and turned the A/C on)
10:45 26 45 240
10:46 26 45 250 ( I pulled over, idled, turned A/C off, and opened hood to cool off)
10:48 26 0 225 ( I started driving home. A/C off, after temp came down to 225)
10:50 26 0 220
10:55 29 45 220 ( I drove home and stopped driving)



I drove for almost 40 minutes before it jumped to 240. Again after drving with te A/C on it hit 240-250 in less than 5 minutes.

With early stage HG leak the car will idle and cruise (even with the AC on) without a problem. Acceleration and engine load (long uphill) will cause overheating and coolant loss. What I would want to know is was your testing done on flat roads with mild acceleration or a hilly area and/or heavy acceleration? Did acceleration precede the overheating events?

jrwoods
07-27-10, 04:21 PM
Sorry for hijacking thread. I moved the question about insurance to the seville forum.

Ranger
07-27-10, 04:39 PM
Posts removed.

tateos
07-27-10, 07:38 PM
HG gets my vote

jeffrsmith
07-31-10, 08:29 AM
With early stage HG leak the car will idle and cruise (even with the AC on) without a problem. Acceleration and engine load (long uphill) will cause overheating and coolant loss.

This is exactly what mine did, but when mine did it I was new to the N* and didn't know better, so I tested with a block leak detector kit and confirmed my suspicions.

HG get my vote also.

mnalep
08-02-10, 05:45 PM
Zonie, I was just driving, what I would call normally, when the overheating occurred. I had stopped at red lights sometimes, but I was not accelerating like I was racing, and the roads were flat.

Jeff, My tests with the blue test fluid that turns yellow shows very little change to a light blue, or maybe slight blue/green tint after 20 minutes of testing. I placed some fluid in contact with gases from the tailpipe and it turned yellow in less than 1 minute - so I am not getting definitive results with the block test fluid for exhaust gases in the coolant.

I had a mechanic say it sounds like the radiator is not cooling efficiently - from the radiator being plugged up. He said that overheating under a load, without losing much coolant sound more like a bad radiator than a leaking head gasket. What do you think?

I called a rad shop, and they said to bring the rad in, and they would look at it, and if plugged could clean it with a mixture of a de-greaser and muratic acid. This is only $35.00. I think I'll do this.

zonie77
08-02-10, 11:25 PM
The HG's still have some pressure on them, that's why the N* acts in a different fashion.

The only things worth checking first are the surge line, pressure cap, and water pump belt. After that it's check the HG's.

Anyone without N* experience has a hard time accepting HG's from these symptoms but most of the guys here have fought through and accepted that the HG's were the problem.

jrwoods
08-03-10, 10:36 AM
Jeff, My tests with the blue test fluid that turns yellow shows very little change to a light blue, or maybe slight blue/green tint after 20 minutes of testing. I placed some fluid in contact with gases from the tailpipe and it turned yellow in less than 1 minute - so I am not getting definitive results with the block test fluid for exhaust gases in the coolant.
In my opinion, the fact that you have a slight green tint is evidence of small amounts of exhaust gasses in your cooling system. Remember that blue + yellow = green. It wouldnt have a green tint unless the gasses caused the slight yellowing of the blue liquid, or the greenish color.




I called a rad shop, and they said to bring the rad in, and they would look at it, and if plugged could clean it with a mixture of a de-greaser and muratic acid. This is only $35.00. I think I'll do this.

Also, in my opinion, this sounds like pretty harsh treatment for an already failing HG.

jeffrsmith
08-06-10, 04:48 PM
Run it again until you get it to "boil" in the overflow tank - then test it. I would be willing to put money on it that the test fluid will turn yellow.

Submariner409
08-06-10, 06:54 PM
Post #7 - If you ran the snot out of the car, parked and took the pressure cap off - any normal car - all hell would break loose: You NEVER take the pressure cap off a hot cooling system.

The Northstar series thermostat is set to begin opening at 188 and be fully open at 206. The system will normally run at 198-210 or so.

Everybody read Post # 34 again. Explain why this engine consistently runs at around "220" regardless of whether it's idling or at 45 mph. This is NOT typical of head gasket failure, and the "20 minute" coolant gas tests are not called for in the tester directions. A change to "light blue" is paranoia at its best. If the fluid doesn't change to definite green or yellow, the test is good/inconclusive. The picture of coolant in the test tube negates every subsequent test unless the entire test rig was washed and cleaned with fresh water.

Has the reservoir pressure cap (16 psi ??) been tested (if so, I didn't see that), the coolant has been drained/changed at least 3 times since the start of the thread, and has the OP checked the water pump drive for proper belt tension and operation ??

I believe this car has a coolant circulation problem or maybe fan control problems, not bad head gaskets, but that belief does not explain why there are a million other Northstars running around out there with no clogged radiators or blown head gaskets - 'tis a mystery...........

mnalep
08-12-10, 06:52 PM
Submariner, The surge tank cap is new. I also tested it with a pressure gauge I rented from Autozone - and it holds good pressure - as does the entire cooling system.

I have not yet ordered a new rad - but I do plan on doing that soon.

jrwoods, Why does cleaning the radiator seem harsh to you?

jrwoods
08-13-10, 04:50 PM
jrwoods, Why does cleaning the radiator seem harsh to you?

Be careful of harsh chemical flushes because they can cause more damage than good, especially to aluminum heads, intake manifolds, and the engine block, read the warning carefully on the label.

Submariner409
08-13-10, 05:08 PM
jr, The Northstar intake manifold is a fiberglass/plastic composite and is dry: no coolant comes anywhere near it. All head/block coolant transfer is done by the coolant crossover on the rear of the block.

mnalep, if you are truly worried about doing a radiator cleaning, remove it and have a professional radiator shop clean and pressure test it for you. jr is correct in the cleaner caution - some of that stuff is death on aluminum.

mnalep
08-15-10, 11:00 PM
jrwoods. submariner, Thanks for that warning. I think I will buy a new radiator instead of cleaning the old one at the rad shop. I saw a radiator on rockauto.com for about $150 (Spectra premuim brand)

KHE
08-16-10, 08:56 AM
Is the purge line flowing? I did not see where that was checked during the troubleshooting process. Pull the line at the surge tank and have someone start the engine. There should be coolant flow from the hose. If not, the purge line is plugged.

In my opinion, replacing the radiator is a waste of time and money.

mnalep
08-16-10, 01:48 PM
KHE, You might be correct, but half the folks I am speaking to think it might be the radiator.

I found one from Rockauto.com. It's $146.79 for a Spectra Premium CU2490. This is the same one Autozone sells for almost $100 more.

At this point I figure it's worth it to try it. If it does not resolve overheating, I'll have an almost new rad for sale, lol.

Anyone know if this is a good brand radiator? Or have other recommendations?

mnalep
08-18-10, 09:53 AM
jrwoods, i was just wondering when you were warning of harsh chemicals doing damage to the engine heads and block - was that even if I take the radiator to a radiator shop for cleaning?

The radiator ship is who said they use a solution of muratic acid, and degreasers, to clean the radiator while it is out of the car.

I would hope they rinse that out well - before I would reinstall in my car, so that none of that acid gets to the heads/block?

submariner, Is this what you are telling me also? Let them clean and test it? I hope I did not leave you with the impression that I was going to clean it myself with a muratic acid solution

Submariner409
08-18-10, 10:32 AM
I shudder to think how many brass and aluminum radiators I have had professionally cleaned during my gearhead career. Not one of them gave me a seconds' problem afterward. If those guys can build a radiator from scratch I would hope they at least know how to clean one...........

Some of the chemicals we use to clean marine heat exchangers (coolant-to-seawater "radiators") would curl your hair............

mnalep
08-18-10, 05:04 PM
khe, yes, te purge line is flowing

mnalep
08-18-10, 05:07 PM
The radiator shop said the plastic tanks looked to weak to test it, he said he would break the tanks if he pressurized them, or do a flow test on them. So - no cleaning after all. He saw small crack in the ribs of the black plastic side tanks.

I ordered a new radiator for $125, should arrive in 3 days or so - even though I am not sure that is the problem - the only other choices are a head gasket repair. or rebuilt engine - so I think spending the $125 is a calculated risk - that some think could fix the problem

mnalep
08-18-10, 05:29 PM
So I've tested 2 new 180 degree thermostats from Autozone in a pot of water on the stove, with a candy thermometer to read the water temp.

Both thermostats did not open at 180 degrees - they started to open at around 190 to 195.

They appear to open at around 200 degrees - and stay open at that temp.

At 200 it stays open about 1/2 inch.

At 190 it stays open about 1/4 inch.

Is this normal?

Submariner409
08-18-10, 07:07 PM
Yes. The Northstar thermostat is supposed to begin at 188 and be fully open at 206. That's an 18 degree warmup spread. Allow a few degrees either side for wax pellet and spring tolerances and you're right in the target. Not a problem. Your engine should run at 198 - 220 all day long, depending on the A/C function called for: remember that the cooling fans are either run in SLOW by the PCM when A/C is set, or if A/C is OFF then 224 to SLOW and 236 to FAST. I would scratch my head at 240, otherwise, drive the car.

ANGONA24
08-18-10, 10:56 PM
I have a 2000 De ville DTS that had a similar problem every time I drove I lost fluid out of the expansion tank and it was overheating, I was told it was a head gasket because there was too much PSI in the system from exhaust gas, so I did a PSI Test on all the cylinders and they checked out fine, I then took the surge tank out and cleaned the heck out of it I rain my hoes through it along with tapping it just a little on the ground to break up old sludge/build up that was in it, I then tried to clean my return line but ended up breaking it. I could not find one nobody seemed to have it. So I did the next best thing make one, I got a 5/8 truck brake line from advanced auto cut it to the same length and I used a pipe bender to curve it just a little like the old one was then ran the hose to the return line and from the t-stat. I also got a kit from thermagasket at rxauto.com which adds another line to the return line from the upper hose and treats for a blown head gasket from doing all of this my cars overheating problem is fixed I do not overheat AT ALL and I never lose any fluid I have drove the car 2k miles since I did this. I was very skeptic with doing this because never in my life would of thought a fix in the bottle would work but I just bought the car and did not want to spend $3K-5K for a new engine the kit was around $130 and to me it was worth it, even if it the problem does come back in a few months I got my money’s worth. So now on to the next head-ack.

Submariner409
08-19-10, 09:15 AM
:hmm: Huh ?

I think you said that you broke the purge line nipple off the reservoir and repaired that, which is good; then you poured Thermagasket into the upper radiator hose, which is a no-no.

.........remember that the proper coolant level in the reservoir is half full, cold.

ANGONA24
08-19-10, 10:15 AM
No the return line that runs by the T-Stat back to the tank is what I broke and had to replace (under the N* cover there is 2 steel coolant lines I think they are 3/4 black lines one goes from the rubber hose that is attached to the tanks Nipple to rubber hose that goes by the T-stat housing thats the one i broke) Also I did not ad the Thermagasket into the upper radiator hose I added it in to the tank, but it also comes with this kit that plugs into the upper hose and makes a 2nd return line to the tank. I will get some pics up with what it is I am trying to explain All I know is that I had the same problem that this guys having and like I said my dts runs like a dream well at least the engine and for now. but I do have some other issues I need to work out.

mnalep
08-19-10, 11:33 AM
angona,

Thanks, but I'm not ready to add stuff like thermagasket to my car.

I am still trying to fix it with a through cleaning, and then a new Radiator (which is on order). Yesterday after taking the rad out, I disconnected several coolant hoses and flushed as much of the system as I could with a garden hose.

I put the ends of upper and lower house on the engine (but no on the radiator since that is now out of the car), and with the thermostat removed - I flushed from both directions.

Then I removed the upper purge line to the purge tank, and flushed through there.

Then I removed the bottom 1" thick hose from the bottom of the purge tank and flushed through there.

Lastly I removed on of the heater core hoses (the one that is near the purge tank, and runs to the thermostat housing and sprayed through that). This one was interesting because what came out of the upper hose for about 1 minute appeared to be a white foamy stuff, almost like dish soap bubble. After a few minutes of spraying water through - it turned clear.

I am wondering if this was some cleaner left either in the heater core, or the block, that I managed to flush out?

mnalep
08-19-10, 11:37 AM
Oh, and I just noticed what looked like a oxygen sensor plugged into the bottom drivers side of the engine. Real easy to get at now. Maybe I should change this? I did get an O2 sensor message of 'no signal' a few months ago, I think it said bank 2, sensor - but I'll need to look for where I wrote it down, and then see if that is the one. It does look like it could have gotten dripped on when the water pump was leaking...

Ranger
08-19-10, 12:03 PM
Don't replace any O2 sensors unless they are throwing DTC's and then figure out which one it is.

mnalep
08-19-10, 12:31 PM
Ranger, I found my note and I had a P0154 - no signal received, from bank2, sensor 1 - and that is the one I can see clearly now with the rad and air ducts and hoses out of the way.

I got that P0154 a while ago, maybe 2 months or so. I have not had another SES code since then, So maybe the problem was a loose or wet wire that resolved itself?

If not, I was thinking now might be a good time to test/replace that O2 sensor.

Or maybe I should just wait and see if the new radiator resolves my engine heating problems?

Ranger
08-19-10, 11:37 PM
Hard to say. You're call. "No signal received" leads me to think it is not the sensor.

mnalep
08-23-10, 12:14 PM
Well I won't touch the oxygen sensor until I see if the new radiator resolves the overheating problem.

I just received the new rad today, and will be installing it soon.

jimsbox
08-25-10, 02:00 AM
For what its worth, my 00 DHS did exactly what yours is doing as far as symptoms including several negative block tests (stayed blue), te but none on boiling surge tank after driving on hills and eventually losing antifreeze at prodigious rate but none on the ground, then one day I was working on the air conditioner and ran into the house for a couple of minutes, came back out and temp gauge went way up and then had a solid yellow block test. It sounds like you are in the early stages of HG failure as many of the previous posters mentioned. I changed out radiator, thermostat, waterpump etc. before I got my yellow test.

I am in the process of studding a yard engine now to swap out (my engine has 280k, this one about 65k). Good luck and put Jake on your speed dial.

mnalep
08-25-10, 04:51 PM
I installed the new radiator today, and took the aurora for a test drive.

It seems things have improved, but I am still on the fence about overheating being fixed.

I drove for about 30 minutes, no a/c on, and the car stayed around 210 or less.

I turned the a/c on, and drove for 45 minutes with the temp staying around 220 to 225. Previously the temp would hit 240 or more within 3 minutes of turning a/c when driving. So - there is big improvement.

BUT, when I parked it in the driveway after the test drive and opened the hood, I could hear bubbling in the surge tank - sort of like the sound you hear when you blow into a glass of water with a straw in it!

I also am seeing the "LOW COOLANT" message show on the dash.

I saw LOW COOLANT when the car was basically cold when I started to drive it. I tried topping the tank off when it was cooler, but it coolant was getting above the 'FILL COLD' mark, so I stopped filling it and went for a test drive. i hit the RESET button on the dash.

Then at the end of the test drive, after I was hearing the bubbling in the surge tank, I turned the key to accessory position to see the temp reading, and the LOW COOLANT message appeared again. The temp indicated about 225 - so the 50/50 coolant mix should not be boiling, right?

After it cools I am going to inspect the level in the surge tank, and test the coolant concentration again.

If the coolant level looks ok, and concentration looks ok, the only thing I can think to do is to jack up the drivers side, again, and try burping it, again.

mnalep
08-25-10, 04:55 PM
Jimsbox, You reminded me to check for gases with the blue liquid also!

Good luck with the studding and gasket job. I am still holding out a little hope that I don't have to do that also, because I have improvement after the new radiator was installed (see my post above).

mnalep
08-25-10, 10:54 PM
Well the coolant has cooled down, and the coolant level is at the FILL COLD mark on the surge tank.

But the LOW ENGINE COOLANT is still coming on?

And, now I am seeing some black dots on the surface of the coolant, and the inside of the surge tank. If this is oil, then do I have bad head gasket?

It's looking like the pictures I posted on page 1 of this post...

Ranger
08-26-10, 12:55 PM
BUT, when I parked it in the driveway after the test drive and opened the hood, I could hear bubbling in the surge tank - sort of like the sound you hear when you blow into a glass of water with a straw in it!

I also am seeing the "LOW COOLANT" message show on the dash.
It is almost a sure bet that the head gasket has a breach.

mnalep
08-26-10, 11:12 PM
Ranger, Not what I want to hear! And I'm confused as to why I am getting a noticeable lack of overheating with the a/c on?

I will revisit some more testing, block test fluid again, maybe inspect plugs, maybe figure out how to do the leak down test you mentioned earlier.

I was looking for pictures posted on the web of others who knew they had oil in the coolant tank, and the one picture I found did not look like mine:

http://img291.imageshack.us/img291/9175/copyof1004591fr4.jpg

I did stumble across a site that was following a class action suit against GM for the DexCool coolant, and saw one picture that looked much more like the black stuff in my surge tank. They were calling it iron oxide? It's about the 6th picture when you scroll down the link below:

http://www.imcool.com/articles/antifreeze-coolant/dexcool-macs2001.php

But then here is another pic of so called iron oxide problem, and it looks nothing like mine:

http://pics.tdiclub.com/data/3629/medium/Dexcool.JPG

Also, I just remembered that when I took the rad out and flushed the system, I also took the surge tank off and cleaned it, and used some dish soap to try and clean out the black 'stuff' that was on the sides of the tank.

Could the dish soap, or hose spraying in the tank, caused the coolant sensor to break?

How do you test the sensor? I am a novice with meter. Does it put out current when it is covered with coolant, or when there is a certain amount of pressure? How much current? DC volts, or DC Amps?

I'm getting pretty tired of this! I just want my car running again!

Ranger
08-27-10, 11:41 AM
Ranger, Not what I want to hear! And I'm confused as to why I am getting a noticeable lack of overheating with the a/c on?
When you put the A/C on, the cooling fans automatically come on. I suspect that is the reason, though as it gets worse that will no longer help.


I was looking for pictures posted on the web of others who knew they had oil in the coolant tank, and the one picture I found did not look like mine:
Oil in the tank?


Could the dish soap, or hose spraying in the tank, caused the coolant sensor to break?

Soap wouldn't, but who knows what a hard spray from a garden hose would do.


How do you test the sensor? I am a novice with meter. Does it put out current when it is covered with coolant, or when there is a certain amount of pressure? How much current? DC volts, or DC Amps?

:noidea:

tateos
08-27-10, 02:26 PM
You can keep screwing around this thing for awhile, but those of us that have been down this path know what you understandably are reticent to believe - you have a HG problem and your engine needs to come out and be drilled and tapped for studs or inserts.

mnalep
08-27-10, 07:23 PM
When you put the A/C on, the cooling fans automatically come on. I suspect that is the reason, though as it gets worse that will no longer help.


Oil in the tank?


Soap wouldn't, but who knows what a hard spray from a garden hose would do.


:noidea:

Ranger,

What I meant was - before I put the new radiator in, the car would climb to 240+ within a few minutes of driving. Now, with new radiator, I drove it for 40 minutes with a/c on, and it never went over about 225.

Regarding 'oil in the tank', I was referring to black specs in the coolant surge tank, that I was hoping, was not oil. That is why I was searching the web for pics of how oil really looked in other peoples coolant surge tanks.

As I think about that coolant sensor, I think it was located where it probably did not get directly sprayed on by the garden hose when I had the surge tank out to clean it.

mnalep
08-27-10, 07:24 PM
Tateos, I hate to hear that ....

Submariner409
08-28-10, 10:19 AM
Black specks in the reservoir..........black chips or black oil slick floating around on top of the coolant ?





Ranger,

What I meant was - before I put the new radiator in, the car would climb to 240+ within a few minutes of driving. Now, with new radiator, I drove it for 40 minutes with a/c on, and it never went over about 225.

Regarding 'oil in the tank', I was referring to black specs in the coolant surge tank, that I was hoping, was not oil. That is why I was searching the web for pics of how oil really looked in other peoples coolant surge tanks.

As I think about that coolant sensor, I think it was located where it probably did not get directly sprayed on by the garden hose when I had the surge tank out to clean it.

mnalep
08-28-10, 12:52 PM
submariner,

Black specs is how I describe it. They feel 'waxy', but I don't think it's oil.


http://img710.imageshack.us/img710/5770/img2481c.jpg
http://img710.imageshack.us/img710/5770/img2481c.jpg

http://img710.imageshack.us/img710/3135/img2478e.jpg
http://img710.imageshack.us/img710/3135/img2478e.jpg

(These 2 pics, and a few more, are on page 1 of this post).

Ranger
08-28-10, 02:52 PM
That MIGHT be sealant tab sediment.

Submariner409
08-28-10, 04:04 PM
That's some sort of residue or sediment - not engine oil.



That MIGHT be sealant tab sediment.

mnalep
08-28-10, 06:14 PM
sub, mariner, That's what I thought also - some residue, seal tabs, rust, or?

I drove it today for over an hour, and things were looking positive.

Drove for about 40 minutes with a/c off - and the temp stayed around 210.

Drove for about 40 minutes with a/c on - and the temp stayed mostly around 220 - 225.

Temp spiked once to about 230+ as I was stuck in traffic, waiting for a long funeral procession to pass.

Came back down to around 220 - 225 with more driving and a/c still on.

I pull in driveway, a/c still on, and decide to let it idle to see how it would get. It climbed to about 245 in under 5 minutes.

Under the hood, i again heard bubbling in the overflow tank. I decided to sniff around the coolant cap with the blue block test fluid, and still no change to yellow.

I opened the coolant cap a bit, thinking I'd help the air/gas escape, and tested with the blue fluid some more - and still no change to yellow. Since I was just driving and hour, and the temp was up to about 240 - I figured this would be a great test. Still don't know what that blue block test means? I did open the cap a bit more - too much that time, and lost a bit of fluid.

I was starting to feel good driving it, and seeing the temp stay under 225, for over an hour! I'm still not sure what is going on - but I'll drive it a few more times. I also think I'll order that OEM 18 psi cap from rockauto.com - maybe my cap is bad - even though it's only 1 month old. But it is a 15 psi, no oem, from autozone.

I was also reading a link yesterday that says a car can overheat if the catalytic converter is plugged up - which causes back pressure into the engine. It suggested to test the vacuum while revving - and if vacuum drops - it may indicate bad cat. Also something about temp diffrence of over 10 degress from front and back of the cat converter.

Here's the links I was reading:

http://www.aa1car.com/library/overheat.htm
"Excessive exhaust backpressure -- A clogged catalytic converter will restrict the flow of exhaust and cause heat to back up in the engine. Other causes include a crushed exhaust pipe or a collapsed double wall pipe. Check intake vacuum at idle. If intake vacuum reads low and continues to drop, inspect the exhaust system."

http://www.aa1car.com/library/converter.htm
"If the outlet temperature is a lot hotter (more than 500 degrees F) than the inlet temperature, it indicates unburned fuel in the exhaust"


http://wiki.answers.com/Q/Why_is_catalytic_converter_overheating
'A catalytic converter overheats due to an excess of unburned hydrocarbons reaching it through the exhaust stream for an extended period of time. This overworks the catalyst bed inside the converter, which then starts to become plugged, generating even more heat as it does. In short order, the converter will become a significant exhaust obstruction, causing the engine to overheat and lose power."

http://autos.yahoo.com/maintain/repairqa/battery_electrical/ques083_0.html
"The easiest test for converter plugging is done with a vacuum gauge. Connect the gauge to a source of intake vacuum on the intake manifold, carburetor or throttle body. Note the reading at idle, then raise and hold engine speed at 2,500. The needle will drop when you first open the throttle, but should then rise and stabilize. If the vacuum reading starts to drop, pressure may be backing up in the exhaust system. "

Ranger
08-29-10, 12:51 AM
Under the hood, i again heard bubbling in the overflow tank.
bubbling in the tank is either coolant boiling or exhaust gases pressurizing the cooling system and escaping into the tank.


Still don't know what that blue block test means?
Blue means no exhaust gases in the cooling system. Head gaskets good. Yellow means just the opposite.

mnalep
08-29-10, 04:34 PM
Test drove it again today, while it was 90 degrees out, and with the a/c on it remained at around 205 for about 15 minutes, and did get to 220 after about 20-25 minutes. I pulled in my driveway, and this time when I shut the car off I did not hear the bubbling in the surge tank.

This is better than last time. I will need to drive more to see if this remains good.

mnalep
08-30-10, 10:37 AM
I drove it last night for over an hour, while it was 75 degrees out, and things were looking positive again.

Drove for about 30 minutes with a/c off - and the temp stayed around 200.

I pull in driveway, and turned engine off, left key on. Temp rose to 220 in a minute or so just sitting. Opened the hood and did not hear bubbling.

I decided to drive it more, and pulled out of drive, and within 1 mile the temp came down to 205, and within 3 miles came down to 200.

Drove for about 30 minutes, with a/c on, and the temp stayed around 205.

Then pulled in driveway, engine off, key on, and again see temp rise to 220. Listened for bubbling and did not hear any, but I thought I heard a small hissing noise - from near the surge tank cap. Not really sure what I heard though.

So this was the 3rd test drive, and I am beginning to feel pretty good, but I am afraid to call it fixed! I am going to drive it again today when it gets up to 90 degrees out (much hotter than the 75 degrees it was last night).

I was reading that the pressure test kits, which have metal screw on attachments that screw on the coolant tank, can mess up the plastic threads on the coolant tank. Since I did this earlier in this saga - maybe my threads/cap are not perfect anymore.

Seeing as how my 'low coolant level' message' persists, and I thought I heard hissing from the cap area - I am thinking I should order, another surge tank with the sensor in it. Then maybe get a new 18 psi cap?

Submariner409
08-30-10, 11:01 AM
For the reservoir, snoop around on Amazon.com, automotive. I scored a Seville tank, with level sensor, for $60 shipped.

If you even think you heard that cap hissing, spend the $8 for a new one at NAPA. 16 or 18 psi is OK.

220 at idle with A/C or no A/C is not uncommon. You know the fan sequences now....your temp indication after the 1 mile-3 mile drive is right on target.

A pressure test kit at this point will tell you nothing - if you're not losing coolant, the engine doesn't miss for a minute after cold start and it doesn't overheat (as in: boil) going up hills, then you're on the right track: radiator and condenser cleaning as well as proper airflow from fans and grille area.

mnalep
08-30-10, 11:10 AM
Sub,

I'll shop around and see find the best price for surge tank/sensor, and cap.

The 220 was after I shut car down (not idling). I just left key on to see how temp rose after car was turned off. It was idling under 220 last time I tested.

The type of driving I did was on flat roads. mostly averaging around 40mph - 45 mph. There was very little traffic, as it was 11:00pm at night, and a 75 degree, nice, cool night.

It's not hilly where I live. I am building up the courage to take it on freeway, and gun it a few times. The steepest hills around me are the freeway off-ramps!

Ranger
08-30-10, 12:07 PM
Rising temps after shut down is normal. The engine is hot, but the cooling system has been shut down. It's called "after boil".

The "hissing" you hear is probably the A/C system equalizing pressure from the low and high side after being shut down. Also normal.

Submariner409
08-30-10, 02:58 PM
From the old memory bank: The A/C system shutdown noises - it can also sound exactly like a radiator boiling as the accumulator equalizes.



Rising temps after shut down is normal. The engine is hot, but the cooling system has been shut down. It's called "after boil".

The "hissing" you hear is probably the A/C system equalizing pressure from the low and high side after being shut down. Also normal.

mnalep
08-30-10, 03:52 PM
OK, This is the 4th test drive this afternoon, after installing the new radiator, and I drove for over an hour, while it was 90 degrees out, and things were looking mostly positive again.

Drove for about 30 minutes (15 miles) with a/c off - and the temp stayed just a hair over 200.

Then turned a/c on, and after 10 miles the temp was mostly about 220. (up almost 20 with a/c on).

Then it went to about 230, and I started to worry. I kept on driving though, and for another 20 minutes the temp fluctuated between about 225 and 230.

So then I decided to test if tunring the a/c off brought the temp down. So I turned a/c off, and in about 2 miles the temp was around 220, and around 4 more miles it was around 210, and around 6 miles about 205.

Then pulled in driveway, engine off, key on. Listened for bubbling - and did not hear any, and no hissing noise either - from near the surge tank cap.

So this was the 4rd test drive, and it seems fine with no a/c on.

Is around 230 ok with a/c on, and 90 degrees out?

mnalep
08-30-10, 03:59 PM
Also, the process I used to fill the coolant back up after installing my new radiator was I looked up the coolant capacity, and it said 13 some quarts.

So, figured I probably had water left in the system from flushing, I added 6 quarts of pure antifreeze. (About half the capacity).

I was then going to add as much 50/50 as needed to top of the coolant tank, and I figured another 4 quarts at least, but it only took about 1 more quart?

This would mean the system had about 6 quarts of water from the flushing still in the block and heater and hoses? Does this sound right?

If not I may have too high a concentration of antifreeze to water (which is not good as water has better heat transfer than antifreeze.)

Submariner409
08-30-10, 05:53 PM
GM allows you to go to a maximum of 70/30 coolant to water. FWIW, a 70/30 mix at 16 psi raises the boil point to 276 degrees (a 50/50 mix at 16 psi is 265 degrees). Don't sweat it, but remember not to overfill that reservoir: half full, cold. No more.

4,5,6,7 quarts will [I]always[I] remain in the block and heater unless you use a vacuum exchange process. One reason we never recommend flushing: if your old coolant concentration is close to 50/50 before the change, the new mixture has more than enough additive package to protect the engine.

Carefully read the back label of a jug of raw coolant. The fine print says the same as Para.1.

mnalep
08-30-10, 08:52 PM
submariner, So I'm in the ballpark, probably close to 50/50. That's good.

I do need to check the reservoir level again, because it is about an inch or so above fill cold mark last few times I've looked.

I keep checking the tank level, thinking it will go down, because it did before but it's staying constant.

I need to empty the tank and look into that coolant level sensor in the bottom of the tank. I'll make sure to add just to the fill cold line when I put the tank back in the car.

I do have a 15 psi cap, should I stick with that?

Does the temp, even up to 230, sound ok?

Ranger
08-30-10, 09:57 PM
Use whatever cap the car came with. 15 sounds about right. 230 is a tad on the high side. but if it doesn't go any higher it should be OK. Take it out and give it some WOT and see what the temp does.

mnalep
08-31-10, 04:43 PM
I took the coolant surge tank off the car to fix the coolant sensor level today. Good news is that after rinsing and shaking that coolant tank I hearrd the sensor level float arm start to move again, so it was stuck, and now my 'low engine coolant' warning is gone.

I had to siphon the coolant tank, and clamped the lower inlet hose, to not lose much from the system. After I reinstalled I added about 1 quart less than was in the tank - as it did look about 1" over the fill cold line. I also put about 1 quart of the old 50/50 and about 1/2 quart water - as I think I was closer to 60/40 antifreeze/water before.

Bad news is that I drove it 15 miles with a/c on, 90 degrees outside temp, and saw that is now running a bit hotter than yesterday.

Today the engine temp said it was around 230 - 235 for the last half or so for the drive, and went to close to 240 once while at a light. (Yesterday looked more like 225 - 230).

So I still don't know if it is fixed?

I am hoping that it may either be in need of burping by driving again (as I did open the system up partially at the coolant tank) - or that maybe the coolant level is lower that required. I'll check after it cools down later tonight.

Submariner409
08-31-10, 06:41 PM
I am hoping that it may either be in need of burping by driving again (as I did open the system up partially at the coolant tank) - or that maybe the coolant level is lower that required. I'll check after it cools down later tonight.


If there is an inch of coolant in the bottom of the reservoir, cold, technically that is enough. The reservoir is not a high flow part of the cooling system: as long as the rest of the system is air-free it will function properly - the reservoir is the high point in the system so it's the coolant expansion/contraction "pressure tank" so to speak.

mnalep
09-01-10, 12:48 PM
Submariner,

Thanks for the feedback.

I drove today for 2nd time after reinstalling surge tank.

This time with no a/c on it was at 220 most of the drive (10 miles), which was hotter than earlier test where it stayed at 205.

Then it hit around 230 for a few minutes, and then 240, at which point I pulled over (after about 15 minutes of driving).

I saw some coolant had escaped - probably vented from the cap, and I heard that bubbling in the tank again.

Maybe this is just the system self burping again, and it will take a few more drives to get air out - at least I hope that is what it is.

If this does not stop after a few more drives, the only thing i can think to try is a new cap, and/or coolant tank?

Darn! It was looking hopeful before I had to remove the coolant reservoir and shake loose that coolant level sensor in it.

This last test had a higher temp with the a/c off, than the previous drive with a/c on!

Ranger
09-01-10, 03:41 PM
I saw some coolant had escaped - probably vented from the cap, and I heard that bubbling in the tank again.
Those are not good signs, especially when accompanied by overheating.

mnalep
09-02-10, 08:43 PM
Drove 3rd time last night. Temp outside was around 75.

Car temp was 220 - 230 for about first 15 minutes, then around 230-235 for 15 minutes, no a/c on.

It did hit 240 after 30 minutes. I pulled over and saw an ounce, or two, of coolant was on the coolant tank.

It looked like the top coolant hose had leaked - so I tightened it up. Also looked like the cap had leaked, so I tightened that up also. NOT feeling too good right now

mnalep
09-02-10, 08:44 PM
Just took it for 4th drive since reinstalling coolant reservoir.

This time I did not open the coolant cap to ensure the coolant level was ok like I have been before every drive. I figured it the car was going to purge itself, I should not keep opening up all the time. Not sure this makes any sense, but I figured the coolant level sensor is now working, so I'll just drive and see what happens.

I drove it for 45 minutes, no a/c on at all.

Temp was at 205 for about first 30 minutes or so.

Temp stayed at just around 220 for last 15 minutes.

After parking I did see a real small amount of coolant, less than a teaspoon, and could hear steam/hissing coming from the cap.

But it never went over 220 in 45 minutes (28 miles) of driving.

Submariner409
09-02-10, 08:59 PM
[QUOTE=mnalep; After parking I did see a real small amount of coolant, less than a teaspoon, and could hear steam/hissing coming from the cap.[/QUOTE]

Didn't go back through this convoluted thread; did you ever install a new pressure cap ??? You should NOT have hissing and steam at 220 - never. No, nada.

The fans don't even go to SLOW until 224 without A/C.....................

mnalep
09-02-10, 10:30 PM
sub,

The coolant cap is about 2 months old, 15psi, from Autozone.

The coolant cap has been through several bouts of temps to, and over, 240 degrees. Do these cap get 'worn out'?

I also had at one time rented a coolant pressure tester, that had steel adapters, that threaded onto the plastic threads of the coolant tank, and the tank cap, while testing. Could the steel adapters messed up the plastic tank, or cap threads?

Regarding the fans, I think they may have been on slow speed when I stopped and parked, and before I turned the engine on...if I recall correctly.

I know this thread is convoluted!! This car is driving me crazy.

Submariner409
09-03-10, 11:37 AM
sub,I also had at one time rented a coolant pressure tester, that had steel adapters, that threaded onto the plastic threads of the coolant tank, and the tank cap, while testing. Could the steel adapters messed up the plastic tank, or cap threads?

Take the cap off the cold tank, and lay it upside down next to the filler neck. Post a couple of pictures from 2 angles..............

mnalep
09-03-10, 04:09 PM
I just took it for another drive, and for about 40 minutes of driving- it was under 225. (Around 205 for first 20 minutes or so).

Then it slowly climbed to 230, then a few miles later to 240 again.

I parked, and again heard steaming and gurgling.

Ranger
09-03-10, 09:55 PM
Don't sound good.

mnalep
09-03-10, 10:41 PM
68103
68104
68105
68106
68107
68108

How do I get the pictures of coolant tank cap/neck inserted inline here?

I managed to get these pictures uploaded as attachments though, please let me know if you can see them by clicking on them.

Submariner409
09-04-10, 09:37 AM
please let me know if you can see them by clicking on them.

Yep - load more than 1 picture and they show up as attachments. "Insert inline" and the attachment links all show up as one "sentence". Weird.

I don't see anything damning in those 6, though.

mnalep
09-04-10, 12:49 PM
I tried just selecting 1 picture, and clicking on post inline, but that did not work for me.

What did wok is if I click the image link above tht I got into this thread from 'manage attachments', then copy the entire url that is displayed in the browser location line.

Then I can paste that image url into the pop up that appears after clicking on 'insert image'.

http://www.cadillacforums.com/forums/attachments/northstar-performance-technical-discussion/68103d1283567854-pics-coolant-test-exhaust-gas-head-img_0036.jpg

Seems like a long cumbersome method.

Anyways, the threads looked ok to me also. Its time to get a pressure tester and test the cap and the system again.

It is seeming more like compression gases causing the bubbling at this point. I need to decide if there are any other cheap things to try, and what test to do next.

mnalep
09-04-10, 01:14 PM
Do you guys ever hear bubbling in the coolant tank?

If this is head gasket, is this just now starting to get bad from the description, or is this as bad as it gets?

Also, I never did put the GM coolant seal tabs in with the new coolant. (A GM parts guy advised that if I had no leaks in the system then do not add the seal tabs). Do seal tabs help this sort of problem, or am I grasping for straws?

Submariner409
09-04-10, 02:18 PM
[QUOTE=mnalep;2353492 .....Also, I never did put the GM coolant seal tabs in with the new coolant. (A GM parts guy advised that if I had no leaks in the system then do not add the seal tabs). Do seal tabs help this sort of problem, or am I grasping for straws?[/QUOTE]

I have never had any indication of bubbling in the coolant reservoir, regardless of how hard I run the car, and my "gauge" has never gone past the 12:45 tick mark under any circumstances. (EDIT at 7 PM: Except when I disabled the fans and did the temperature gauge readings to Paint over JimD's gauge picture.)

If the system was not obviously leaking coolant, there was no reason to install the Bar's tablets (HDC) or powder (G12BP). Sealants won't help - if the head gasket is failing, nothing short of a top overhaul with inserts or studs will stop the process.

Aftermarket sealants are used to plug holes and cracks, so by definition, if the hole or crack is slowly enlarging, the cat is chasing its tail, and depending on the type, over use of sealants may leave the engine and radiator in unusable/non-repairable condition.

Ranger
09-04-10, 04:27 PM
It will slowly get worse to the point of being undriveable.

mnalep
09-06-10, 02:07 PM
sub, well you convinced me not to use sealants.

Ranger, that's what I was afraid of.

I am thinking of trying a new 18psi cap?

Also going to start reading about that leak down test mentioned earlier, and tests to eliminate catalyctic converter as a possible cause.

mnalep
09-06-10, 04:12 PM
Well, I tried this vacuum test for possible clog in the cat converter:

"EXHAUST BACKPRESSURE CHECKS:
To diagnose a plugged catalytic converter, you can check intake vacuum or exhaust backpressure. To check intake vacuum, connect a vacuum gauge to a vacuum port on the intake manifold. Start the engine and note the vacuum reading at idle. Then increase engine speed to about 2,500 rpm and hold steady. Normal vacuum at idle for most engines should be 18 to 22 inches Hg. When the engine speed is increased there should be a momentary drop in vacuum before it returns to within a couple of inches of the idle reading. If the vacuum reading is lower than normal and/or continues to drop as the engine runs, it probably indicates a buildup of backpressure in the exhaust".
http://www.aa1car.com/library/converter.htm

My vacuum at idle was about 19, fell momentarily to about 14 on rev, then came back to about 20 at 2,500 rpm. This indicates that the cat is probably fine per the test above.

Ranger
09-06-10, 09:43 PM
A higher pressure cap MAY help for a while, but it's just a bandaid that will not last.

Eldo1953
09-06-10, 11:36 PM
Sorry man. But stop wasting your time. Time to visit Northstar Performance.

Submariner409
09-07-10, 12:17 PM
My vacuum at idle was about 19, fell momentarily to about 14 on rev, then came back to about 20 at 2,500 rpm. This indicates that the cat is probably fine per the test above.

Due to the Northstar cams and emissions timing the average engine vacuum will be 2-3" less than a comparable carbureted V-8. Your readings are perfect for an unloaded engine - they will drop several inches under driving conditions - normal.

mnalep
09-07-10, 12:21 PM
ranger, I guess I was thinking if the overheat is not from head gasket, that might lower the boiling point a few degrees to where I don't start a bubbling and overheating reaction? I can see that if it's a bad head gasket, the temp will still get as hot as it wants to, it would just take longer to boil and vent - maybe not a good thing for the engine itself.

mnalep
09-07-10, 12:24 PM
ranger, I've been re-reading the cylinder leak down test you pointed me to earlier:

http://www.cadillacforums.com/forums/cadillac-tech-tips/107933-how-do-cylinder-leak-down-test.html.

I had a couple of questions about this test:

The tricky part of the leak down test, to me anyways, is manually rotating the engine, using the 'harmonic balancer' stud, and getting the valves into the correct position (compression stroke, not exhaust stroke).

Would I be able to manually move that engine, even with a long leverage pipe?

Also - would I be screwing up the engines timing or something manually turning it? Does it all have to end up being cranked back into the same exact position as when the test was first started?

Oh, and is this the definitve test for bad head gaskets? I'd hate to do this if this could be inconclusive.

mnalep
09-08-10, 03:57 PM
While it was jacked up I 'burped' it through three separate heat up and cool down cycles.

I had the surge tank cap off, and did notice a few bubbles when I revved it to around 2500rpm. I only notice about 6 or fewer bubble 'events' on each burp cycle. What struck me as odd was I never saw any bubbles while motor was colder, only after it hit around 220 or so.

I figure this is due to thermostat opening up around 220, and letting bubbles pass?

I also tried using the 'block test fluid' on the coolant tank opening for quite a while during this process, and especially after I saw some bubbles, but it never change to yellow color, only to a lighter blue as posted in the pics on page 1 of this post. Makes me think the bubbles may not be exhaust gas? Or very small amount of exhaust gas? (And by bubbling I mean a few random bubbles, about half the size of a dime. Nothing like frothing, or blowing through a straw into a liquid.)

I'm going to test drive it later tonight or tomorrow. See if I what I did changed anything.

I also ordered a new Delco coolant cap. Should be here in the next day or so. I realize it may not help - but since I'm into a very expensive head gasket repair, or engine swap - I figure I may as well try.

Submariner409
09-08-10, 05:58 PM
I figure this is due to thermostat opening up around 220, and letting bubbles pass?


The original thermostat was set to begin at 188 and be fully open at 206. A Northstar and its cooling system in good condition, with no A/C function called for (because then fans run continually in SLOW), will run at 196 to 222, depending on speed and traffic, all day 24/7/365: fans go to SLOW at 224 or so.

tateos
09-08-10, 07:57 PM
Sorry man. But stop wasting your time. Time to visit Northstar Performance.

Yup - no offense, but you bring "denial" to whole new level. When the head gaskets are sealing properly, you can beat the piss out of these things and they will never overheat. When they're blown, no amount of babying, burping, farting, or anything else is going to get you anywhere but the final conclusion that your head gaskets are blown

mnalep
09-09-10, 08:17 PM
Tateos,

No offense taken. You're probably correct.

I just don't see why that test liquid does not turn yellow? It seems to me that if science says the liquid should turn yellow - then it should turn yellow! Or is this just a product that is not worth buying?

I was trying to burp it - hoping that maybe I had air trapped in the system.

mnalep
09-10-10, 05:42 PM
Someone told me to check the trans fluid level, that if too low will cause an overheat.

I think my trans fluid level is ok. It tested HOT just about 1/8 inch below the hatch marks on the trans dip stick. I followed the procedure in the owners manual to test.

Funny thing was when I checked the fluid COLD it did not register on the dip stick?

It overheated again driving after about 15 minutes. But this was still with old coolant cap. I just received a new 18 psi Delco cap, and will test with it later.

I also notice a little bit of trans fluid on the plastic on the undercarriage again.

This is after I tightened up the trans cooler line going into the rad a few days ago.

It's too hot to put my hand down there and see if the trans line nut came loose again, or even if that is where possible drip is happening. I am hoping it is just some left over fluid from the earlier drip that completed falling down. (I know that plastic undercarriage was dry, after tightened up the trans line nut earlier, because I had wiped off that plastic under the car a few days ago).

I also notice the trans fluid had some bubbles at the top when I tested the fluid level. Is this normal after driving for 15 minutes?

Submariner409
09-10-10, 06:45 PM
Remember that the transmission is a dry sump unit: with the engine OFF there will be NO FLUID on the stick. Hot, idling in P, the fluid should be about halfway up the HOT hashmark.

Transmission fluid level has no bearing on engine temperatures.

Because the transmission is a dry sump unit, the pan scavenge pump is designed to pump far more fluid than ever returns to the pan: dry sump. Entirely possible that the fluid surface, when running, could have a few bubbles: that scavenge pump is a great bubblemaker, hence the vent tube with the rattle top clipped to the side of the main throttle cable bracket. Modern transmission fluids have a pretty impressive anti-foam package of additives, and that's the reason for the vent - the fluid in the side tank and pan runs at atmospheric pressure to hasten the deterioration of any foaming.

mnalep
09-10-10, 08:38 PM
sub,

I have to say, you're car knowledge is fantastic.

And thanks for all the help from everyone here.

Now I have a new problem. Either the heater hose rubber line, or steel line, is leaking. I put on the 18 psi cap, and was driving for about 15 minutes. At a stop light I see steam, and a soon after the LOW ENGINE COOLANT turns on. I pull over to cool off, steam everywhere.

When I pull the coolant cap, the reservoir is empty.

I put in coolant, and I see it drain out the bottom.

I nurse the car home (2 blocks) and took out the coolant reservoir and air ducts, and I can feel the clamps & rubber hose & steel hose on the lower heater line is the one that looks like it's leaking. I can just reach it with my hand, and I can feel/see rust on the clamp, on the steel line.

I guess the higher pressure cap caused the pressure to find another way out. The temp was around 220 when this happened.

Now I have to get pliers, or something to reach down to get the clamps off. I might get the top one with my regular pliers. The bottom hose has the clamp grips almost facing downward. Both are right under the brake lines from the master cylinder. So it's tight, and far to reach.

I am really starting to get mad at this car.

Any advice on the heater core lines, pliers or other tool, and if my theory about the 18 psi cap would be helpful, and appreciated.

mnalep
09-10-10, 09:59 PM
The heater hose clamps are under the master cylinder, and the brake lines.

I googled hose pliers and found an abundance of types, some even on a flexible length of cable. I'll head to tools stores, harbor freight, sears, etc. and see what would work.

I'd like to not take the brake lines off the master cylinder for more room, because I don't want to have to bleed the brakes, so I am going to find pliers that will get me down there.

johnny kannapo
09-11-10, 08:44 AM
submariner,

Black specs is how I describe it. They feel 'waxy', but I don't think it's oil.


http://img710.imageshack.us/img710/5770/img2481c.jpg
http://img710.imageshack.us/img710/5770/img2481c.jpg



(These 2 pics, and a few more, are on page 1 of this post).I believe one source of the black specks could be from crossover gaskets

http://i826.photobucket.com/albums/zz183/billytheshoe/100_1166.jpg

The upper rear port gasket just disinegrated. I can see the black material is flaking away on the three gaskets that were still sealing from inside out.

The front lower port gasket has the silicone material exposed where the black material has washed away. The black material was very flakey and appeared to desolve.

I wouldn't rule out that it may be head gasket maerial.

Ranger
09-11-10, 12:05 PM
The tricky part of the leak down test, to me anyways, is manually rotating the engine, using the 'harmonic balancer' stud, and getting the valves into the correct position (compression stroke, not exhaust stroke). Would I be able to manually move that engine, even with a long leverage pipe?
Pull all the plugs and you should be able to rotate the engine with a wrench on the balancer bolt.


Also - would I be screwing up the engines timing or something manually turning it?
No. It will remain in time since the timing chains have not been touched.


Does it all have to end up being cranked back into the same exact position as when the test was first started?
No. It's no different than running the engine except that you are manually turning it (you are the fuel so to speak).


Oh, and is this the definitve test for bad head gaskets?
Yup. That said, I really don't think you need to waste your time.

mnalep
09-11-10, 06:44 PM
Johnny,
That could very well be what those specks in mine are. Are the head gaskets in the 4.0 Northstar NON-metallic? Did you notice stuff like that in your coolant tank?

Ranger,
You think it's my head gasket too?
Would a compression test be a definitive test for bad head gaskets?

Submariner409
09-11-10, 07:18 PM
Johnny,
That could very well be what those specks in mine are. Are the head gaskets in the 4.0 Northstar NON-metallic? Did you notice stuff like that in your coolant tank?


The OEM gaskets are an organic/metallic/graphite composition with a steel seal ring around the top of each cylinder liner.

The sheer volume (amount) of flakes in that test tube (8 fluid oz.) would require one hell of a lot of flaky gasket material to maintain the same concentration throughout the cooling system, not including what would be lying around in the low spots and low flow areas............

No, a compression test will not normally define a head gasket leak: we're not talking open faucets here - it's tiny pinholes, but at combustion chamber pressures that's all it takes to screw up the engine.

mnalep
09-11-10, 10:24 PM
sub,

I guess the flakes are probably not gasket material then. I won't bother trying get a compression test kit then.

I was just thinking that would have been an easier test to perform than the cylinder leak down test that ranger spoke of.

I'm not sure I should put the 18psi cap back on after I do the heater hose? Could the 18psi cap be the cause of the heater line giving out?

Ranger
09-11-10, 11:08 PM
A leak down test is the most definitive, though more tedious. As Sub said, a compression test will show you nothing in regards to a bad HG. If you have overheated a few more times (I did not go back and reread it), do the block test again (if you have not topped off the coolant).

You should not need a higher pressure cap than it came with if the system is operating properly. A higher pressure cap just means that the system will build more pressure before it overflows and obviously put more pressure on the entire system, hoses and all. It won't cure the problem, which does sound a lot like a HG.

Submariner409
09-12-10, 10:05 AM
sub, I was just thinking that would have been an easier test to perform than the cylinder leak down test that ranger spoke of.



The liquid chemical/vacuum coolant gas test is the determinant: Performed properly according to the directions, if, after 2 minutes, that fluid turns green or yellow then your head gasket(s) are leaking. No ifs, ands or buts - all this second guessing and jerking around is fruitless - if it has a leak somewhere it takes nuts and bolts to fix it, not speculation.

(If we go back to Post #1 and the pictures, even though you incorrectly performed the test for 6 minutes, there is certainly no indication of a gasket leak there - what is the test result now, after fooling with this for ~150 posts ????)

The correct coolant reservoir cap for your engine will be listed in GM parts lists or the Stant catalog hanging by the shelf in a large parts house. Some Northstars came with 16 psi, some have 18 psi (my 2002).

mnalep
09-12-10, 10:32 PM
sub,

I've done the block fluid test numerous times now.

All the latest block fluid tests have been done after I have driven the car several times, for a combined mileage of perhaps 150 miles or more.

I've tested while the cap was on, and while it was hissing. I've placed a plastic bag over the hissing cap trying to contain the gas in the plastic bag, while testing with the block fluid tester in the plastic bag.

I've taken the cap off and tested at idle, and while revving the engine to 2000 rpm or more.

I've done each of these tests several times, and for several minutes each. The blue liquid changes to the same light blue as in the pictures first posted. It's not turning yellow - which is why I am having trouble with a diagnosis that the head gasket is leaking.

I did just look up the cap in the Stant online catalog, and it lists 15psi. The cap I ordered was from Rockauto.com, which lists a 15psi, and an 18psi cap. The 18psi I ordered and just used was the 18 psi Delco cap from rockauto.com.

I am going to rent a pressure tester tomorrow, and make sure that new cap is actually releasing at 18psi.

Here are pics of the heater hose clamps, and location.

I plan to go to Harbor Freight tomorrow for tool to reach lower clamps.

http://img831.imageshack.us/img831/7938/img0057bc.jpg
http://img831.imageshack.us/img831/7938/img0057bc.jpg

http://img831.imageshack.us/img831/1037/img0055ad.jpg
http://img831.imageshack.us/img831/1037/img0055ad.jpg

Submariner409
09-13-10, 09:09 AM
Your second picture - the heater hose that loops around over the transmission top and goes to the metal pipe attached to the water crossover - that pipe is held into the crossover fitting by a nylon quick disconnect. If that pipe or the threaded connector at the crossover is partially blocked it will screw up heater circuit flow. (You have it labeled, in the blue rectangle - 1st upper heater hose clamp.)

johnny kannapo
09-13-10, 12:21 PM
Johnny,
That could very well be what those specks in mine are. Are the head gaskets in the 4.0 Northstar NON-metallic? Did you notice stuff like that in your coolant tank?

I am sure the head gaskets would be far different from the cooling system seals. I cant really say I noticed any debris in the fluid. It was new last fall and I did use a chemical flush back then and it appeared a bit cloudy. My reservoir is black so it would not be easily seen at the tank. You can clearly see the in side perimeters of all those gaskets are washing away after 14 years.


http://i826.photobucket.com/albums/zz183/billytheshoe/233d254f.jpg

http://i826.photobucket.com/albums/zz183/billytheshoe/100_1180.jpg

mnalep
09-13-10, 06:47 PM
Here are some more pictures of the heater core hoses, and lines.

I have found a small hole, a little more than a pinhole, in the steel part of the heater core lines. You can see it in the picture.

So, I assume the hole just blew open on my test drive!

The steel line has rust on it, and would have been weak.

The last pic show the awful location of the steel line as it enters some more rubber hoses that go into the firewall.

Anyone think I can just try and pull the rubber hose over the pinhole and re-clamp it? I doubt that is a good idea!


http://img29.imageshack.us/img29/8677/img0065an.jpg
http://img29.imageshack.us/img29/8677/img0065an.jpg


http://img38.imageshack.us/img38/4030/img0066ah.jpg
http://img38.imageshack.us/img38/4030/img0066ah.jpg


http://img834.imageshack.us/img834/1038/img0074ad.jpg
http://img834.imageshack.us/img834/1038/img0074ad.jpg

http://img683.imageshack.us/img683/8499/img0078aa.jpg
http://img683.imageshack.us/img683/8499/img0078aa.jpg

mnalep
09-13-10, 07:17 PM
Your second picture - the heater hose that loops around over the transmission top and goes to the metal pipe attached to the water crossover - that pipe is held into the crossover fitting by a nylon quick disconnect. If that pipe or the threaded connector at the crossover is partially blocked it will screw up heater circuit flow. (You have it labeled, in the blue rectangle - 1st upper heater hose clamp.)

I think my crossover is under the thermostat housing. I do see the heater hose line coming out near the thermostat housing. I think this is the heater core inlet line? If the crossover is blocked, I don't see a nylon quick connect?

I did run garden hose water into this heater core line, and saw it come out the top radiator hose, as part of my flushing. It seemed to flow pretty good. But I guess the crossover could still have blockage? The black specs do look like they could be the crossover gaskets deteriorating?

mnalep
09-13-10, 07:38 PM
Anyone know where I might buy that steel heater line (that has the pinhole in it)?

It looks like a pair of lines about 16 inches long. At the firewall end the steel lines go into 2 rubbers hoses, that go into the heater core.

At the other end the 2 steel lines go into the 2 lower rubber heater hose lines.

I've looked at rockauto.com, gmpartsdirec.com, autozone.com, and oreillyauto.copm.

tateos
09-13-10, 08:21 PM
Dealer, junkyard, or maybe hobble something together yourself with copper pipe? You will have plenty of access to it all once you drop the cradle to do the head gasket repair.

Ranger
09-13-10, 09:00 PM
http://www.gmpartsgiant.com/Page_Product/PartDetail.aspx?modelYear=1997&model=Aurora&make=Oldsmobile&catalogCode=35G&modelCode=3GR29&seriesCode=3GR&bodyStyleCode=29&engineCode=L47&transCode=MH1&majorIndexID=08&isBigPicture=False&minorIndexID=3G0801001

mnalep
09-13-10, 09:07 PM
Dealer, junkyard, or maybe hobble something together yourself with copper pipe? You will have plenty of access to it all once you drop the cradle to do the head gasket repair.

Tateos, I do not know how to 'drop the cradle'? I don't even know if I should attempt it. What tools (hoist?, etc.) would be required? I've repaired a ton of things on this car already. I like to learn new repairs, but I'd have to really read up on how to do that before attempting.

I did think about junkyard, but figured they would be rusty also. I thought about taking this one off and shortening the steel in by cutting after the pinhole.

Does this type of hole happen often? My car is 1997 with about 168,000 or so on it.

mnalep
09-14-10, 11:13 AM
http://www.gmpartsgiant.com/Page_Product/PartDetail.aspx?modelYear=1997&model=Aurora&make=Oldsmobile&catalogCode=35G&modelCode=3GR29&seriesCode=3GR&bodyStyleCode=29&engineCode=L47&transCode=MH1&majorIndexID=08&isBigPicture=False&minorIndexID=3G0801001

Ranger, that's it! Thank you so much for that find!

I was unaware of that site before, but it's going to get bookmarked with other favorites.

I was looking for the coolant surge tank cap on that site, but could not find it. I did not see an option to search by part name? (I wanted to see if they listed 15psi, or 16psi, or 18psi). Do you know how I'd find the cap on that site?

STSS
09-14-10, 11:30 AM
They list 18 psi for your car

http://www.gmpartsgiant.com/Page_Product/PartDetail.aspx?modelYear=1997&model=Aurora&make=Oldsmobile&catalogCode=35G&modelCode=3GR29&seriesCode=3GR&bodyStyleCode=29&engineCode=L47&transCode=MH1&majorIndexID=01&isBigPicture=False&minorIndexID=3G0101501

mnalep
09-14-10, 12:50 PM
STSS, Thanks! I had trouble finding that cap on their site.

STSS
09-14-10, 01:40 PM
No prob, I know it's not the best site for searching, but I sure love the diagrams!

tateos
09-14-10, 09:46 PM
Tateos, I do not know how to 'drop the cradle'? I don't even know if I should attempt it. What tools (hoist?, etc.) would be required? I've repaired a ton of things on this car already. I like to learn new repairs, but I'd have to really read up on how to do that before attempting.

I did think about junkyard, but figured they would be rusty also. I thought about taking this one off and shortening the steel in by cutting after the pinhole.

Does this type of hole happen often? My car is 1997 with about 168,000 or so on it.

I think exterior rusting of those steel pipes is rather common in the rust belt - my '97, which spent its first 5 years in New England, and the rest of it's life in the AZ desert, has pipes in very good condition. If your pipe rusted out form the inside out, then it proves that you did not have adequate corrosion protection form the coolant.

Here is a link to my thread on doing the HG repair - it's rather lengthy, but will give you a good overview:

http://www.cadillacforums.com/forums/northstar-performance-technical-discussion/126253-97-etc-n-head-gasket-project.html

Also look here - where I learned a lot from Zonie - the knowledge to try this method:

http://www.cadillacforums.com/forums/cadillac-tech-tips/31831-n-head-gasket-repair.html

mnalep
09-15-10, 12:09 PM
Tateos,

Thanks for those links, I started reading last night and my eyes got tired...I'll read some more in the next few days.

mnalep
09-15-10, 12:10 PM
I rented the coolant pressure tester again yesterday.

The 3 month old 15 psi cap will only hold 15 psi for about 20 seconds - during which the needle visibly drops slowly to about 2psi! SO, it seems with that cap not holding pressure properly - could that have been part of my overheating problem? I don't recall testing it when I bought it new 3 months ago. (The several years old 15psi cap that was on prior to this 3month old 15 psi cap, won't hold pressure at all!)

The brand new 18psi Delco cap holds 18psi for about 30 seconds, and after 6-7 minutes has only dropped to 15psi. (I'm still watching it as I type this).

This new 18spi Delco cap also vents properly when I over pump the pressure to around 19-20psi. (So it was properly venting at 18psi, so I guess was just enough to put a hole in the rusty steel heater line).

Maybe...if I get the steel heater hose line fixed, and use the new 18psi cap (or a new 15psi that really holds 15 psi) - maybe I'll have success?

Ranger
09-15-10, 12:31 PM
The 3 month old 15 psi cap will only hold 15 psi for about 20 seconds - during which the needle visibly drops slowly to about 2psi! SO, it seems with that cap not holding pressure properly - could that have been part of my overheating problem?

Absolutely. Boiling temps are directly related to the system pressure. Lower the pressure and you lower the boiling point.

mnalep
09-15-10, 08:32 PM
That chart gives me a little hope that after I fix the heater core lines, and put on the good coolant cap, I might not overheat.

Ranger, do the rows, other than 50%, mean the percentage of coolant? (IE: the 33% row means 33% antifreeze, 67% water, right?)

Submariner409
09-15-10, 09:30 PM
That chart gives me a little hope that after I fix the heater core lines, and put on the good coolant cap, I might not overheat.

Ranger, do the rows, other than 50%, mean the percentage of coolant? (IE: the 33% row means 33% antifreeze, 67% water, right?)

never mind............

Ranger
09-15-10, 10:10 PM
Yes, those percentages are coolant IE: 33% antifreeze, 67% water.

mnalep
09-17-10, 12:32 AM
Well, the heater core hose assembly is out. The steel line that had a hole is part of an assembly part number 25642183. GM is apparently out of stock, so I got a friendly person at GM parts to find a dealer who still had one in their inventory. (He said he only saw 6 dealers in the country with this part). It's expensive, around $130.00 !

I should receive the assembly in the mail some time in the next 3-4days.

Below are pictures I took of this time consuming process. I did have to buy a special tool, a flexible clamp remover, to get at the clamps on the firewall. (There was no way to get any kind of pliers, vice grips, needle nose pliers, or hose pliers on the clamps, which were just under the a/c lines and on the rubber hoses on the heater core inlets on the firewall). The tool was $35.00 at Autozone.


http://img830.imageshack.us/img830/9568/img0119ai.jpg
http://img830.imageshack.us/img830/9568/img0119ai.jpg


http://img641.imageshack.us/img641/6126/img0124as.jpg
http://img641.imageshack.us/img641/6126/img0124as.jpg

http://img826.imageshack.us/img826/826/img0126ak.jpg
http://img826.imageshack.us/img826/826/img0126ak.jpg

http://img20.imageshack.us/img20/708/img0131aw.jpg
http://img20.imageshack.us/img20/708/img0131aw.jpg


http://img525.imageshack.us/img525/3132/img0134ay.jpg
http://img525.imageshack.us/img525/3132/img0134ay.jpg


http://img267.imageshack.us/img267/5210/img0143af.jpg
http://img267.imageshack.us/img267/5210/img0143af.jpg

http://img46.imageshack.us/img46/42/img0144ac.jpg
http://img46.imageshack.us/img46/42/img0144ac.jpg

http://img243.imageshack.us/img243/5526/img0149au.jpg
http://img243.imageshack.us/img243/5526/img0149au.jpg

tateos
09-23-10, 11:08 PM
We're all waiting for an update.....

mnalep
09-24-10, 02:15 PM
Tateos,

Sorry about that. I've only been able to work on it a little bit this week.

I did manage to get the new heater hose lines installed, and things hooked back up. I put coolant in, and I am going to 'burp' it while it is still up on the jack stand.

Then I'll take it for a test drive, and let you know.

mnalep
09-30-10, 10:43 PM
Sorry guys, I've been away from this for too long.

I had a real bad cold, and with the fever and lack of energy could not work on this car until recently.

I finally took it for a short ride today, with the new 18spi cap, and new heater line assembly. I drove it 22 miles. This was mostly easy driving on side streets, and surface roads, under 45 mph. So about 45 minutes time-wise.

The temp gauge stayed under 220, which is good news.

However, after I parked the car, and if I put my ear right up to the coolant surge tank cap, I could hear a very quiet hiss. I mean very quiet. If I move my ear 12 inches away I could not hear it - and it was a quiet night.

So, I don't know what is up with it yet. I plan to drive it more tomorrow, at higher speeds, and see/hear what happens next.

mnalep
10-03-10, 07:53 PM
I drove it more this evening. This time I drove 50 miles. About 90 minutes. Temp outside was 50, and I had no heat or a/c turned on.

Half of this driving was stop and go driving at up to 45 mph.

Half was on the freeway at up to 65 mph. Actally did about 8 laps onto and off the freeway.

The good news, again, is that the temp gauge only went to 220 four times, then came back down to around 205. During most of this driving (85 of 90 minutes) the temp was at 205.

Bad news, again, is that if I put my ear right up to the coolant surge tank cap, I could hear a very quiet hiss. There was a drop of coolant on the tank adjacent to the cap, and a drop or two on the side of the tank.

I still don't know what is going on here. Do you guys?

Submariner409
10-04-10, 10:28 AM
My guess would be that the tank itself is cracked, the filler neck is somehow leaking (nick in the seal surface ?), the cap is unsatisfactory, or the coolant overflow nipple (is there one on an Aurora engine ?) is cracked.

mnalep
10-04-10, 01:23 PM
Sub, The very quiet hiss I hear is near the tank cap threads.

I was worried the hiss might be from excessive pressure, from exhaust gas entering the cooling system?

Although the tank itself is showing signs of age.

I will check the coolant reservoir threads, and cap, again.

Come to think of it, I was, at one point, thinking about getting a new reservoir, when I was worrying about the steel adapter threads, on the pressure tester adapter I rented, possibly re-threading the plastic threads on the coolant tank.

mnalep
10-04-10, 08:53 PM
I posted some pictures, and a video, of the coolant tank below.

Below is a pic of the coolant tank.

http://i926.photobucket.com/albums/ad107/mnalep/Aurora%20Coolant%20cap%20pics%20and%20Hiss%20video/IMG_0195.jpg

http://i926.photobucket.com/albums/ad107/mnalep/Aurora%20Coolant%20cap%20pics%20and%20Hiss%20video/IMG_0195.jpg

Below is a close up of some of the tiny amount of coolant (green coolant).

http://i926.photobucket.com/albums/ad107/mnalep/Aurora%20Coolant%20cap%20pics%20and%20Hiss%20video/IMG_0196.jpg

http://i926.photobucket.com/albums/ad107/mnalep/Aurora%20Coolant%20cap%20pics%20and%20Hiss%20video/IMG_0196.jpg

Below is a small crack in the coolant tank seam (no leak here...yet)

http://i926.photobucket.com/albums/ad107/mnalep/Aurora%20Coolant%20cap%20pics%20and%20Hiss%20video/IMG_0197.jpg
http://i926.photobucket.com/albums/ad107/mnalep/Aurora%20Coolant%20cap%20pics%20and%20Hiss%20video/IMG_0197.jpg

Below is a pic of the threads on the coolant reservoir.

http://i926.photobucket.com/albums/ad107/mnalep/Aurora%20Coolant%20cap%20pics%20and%20Hiss%20video/IMG_0200.jpg

http://i926.photobucket.com/albums/ad107/mnalep/Aurora%20Coolant%20cap%20pics%20and%20Hiss%20video/IMG_0200.jpg

Below is a close up of the threads on the coolant reservoir.

http://i926.photobucket.com/albums/ad107/mnalep/Aurora%20Coolant%20cap%20pics%20and%20Hiss%20video/IMG_0201.jpg

http://i926.photobucket.com/albums/ad107/mnalep/Aurora%20Coolant%20cap%20pics%20and%20Hiss%20video/IMG_0201.jpg


In the VIDEO below you can hear the pressure escape AFTER I start opening the coolant cap. I could not hear any before opening the cap as this time the car had cooled down overnight.




http://s926.photobucket.com/albums/ad107/mnalep/Aurora%20Coolant%20cap%20pics%20and%20Hiss%20video/?action=view&current=MVI_0199.mp4

http://i926.photobucket.com/albums/ad107/mnalep/Aurora%20Coolant%20cap%20pics%20and%20Hiss%20video/th_MVI_0199.jpg (http://s926.photobucket.com/albums/ad107/mnalep/Aurora%20Coolant%20cap%20pics%20and%20Hiss%20video/?action=view&current=MVI_0199.mp4)


Next time I drive it I'll remember to get a video of the much quieter hiss with the cap still on.

Ranger
10-04-10, 09:24 PM
I don't see any video, but I don't like the looks of that tank in picture #3. Maybe there is another small unseen crack leaking the coolant in picture #2.

mnalep
10-04-10, 10:27 PM
Ranger, the 6th pic (closeup of coolant cap) is actually a link to a video. I can click on it and watch the video (on photobucket).

Please let me know if you can't.

Submariner409
10-04-10, 10:52 PM
Ranger, the 6th pic (closeup of coolant cap) is actually a link to a video. I can click on it and watch the video (on photobucket).
Please let me know if you can't.

I don't like the creases and crevices in the reservoir seal lip - that lip seats into the rubber gasket in the cap, but that rubber cannot fill tiny void spaces.

mnalep
10-05-10, 09:56 AM
I don't see any video, but I don't like the looks of that tank in picture #3. Maybe there is another small unseen crack leaking the coolant in picture #2.


Can you see the video with this link?

http://s926.photobucket.com/albums/ad107/mnalep/Aurora%20Coolant%20cap%20pics%20and%20Hiss%20video/?action=view&current=MVI_0199.mp4

Ranger
10-05-10, 12:06 PM
OK, I could view the last link. Sure looks like from the last part of the video it's leaking from the cap seal and running down. Hard to say if it's the cap or the tank, but being a new cap and the condition of the tank seal at the lip, I'd suspect the tank. Maybe a few light strokes with a file will clean it up.

mnalep
10-05-10, 08:22 PM
I drove the Aurora almost 40 miles today. Made 2 stops, but mostly just driving. The temp stayed around 205 for first part of driving, then went up and down from 210 to 220 for the majority of the drive.

When I parked I saw coolant again - a very small amount. I heard hissing again and tried to shoot the video below to pick up the hiss. You can just hear the hiss when I put the camera right up to the coolant tank cap. It was getting dark when I took this video, so I tried to use a flashlight, but it is still a bit dark.

Video of hissing after I turn car off.
http://s926.photobucket.com/albums/ad107/mnalep/Aurora%20Coolant%20cap%20pics%20and%20Hiss%20video/?action=view&current=MVI_0204.mp4

http://i926.photobucket.com/albums/ad107/mnalep/Aurora%20Coolant%20cap%20pics%20and%20Hiss%20video/th_MVI_0204.jpg (http://s926.photobucket.com/albums/ad107/mnalep/Aurora%20Coolant%20cap%20pics%20and%20Hiss%20video/?action=view&current=MVI_0204.mp4)

Submariner409
10-05-10, 09:57 PM
Get on www.amazon.com (http://www.amazon.com) - automotive - and find a GM coolant reservoir for the car. The damaged filler lip and the side seam crack point to ever increasing problems. For $68 or so, level sensor and shipping included, you can take the tank out of the equation. If no joy on Amazon, try www.gmpartsgiant.com or rippypartsmaster.

EDIT at 10:15 : GMPartsGiant - your car, cooling, hoses and radiator, surge tank - $55.

mnalep
10-06-10, 06:56 PM
sub, I see Amazon has it for 52.79, with free shipping.

I was not sure the coolant tank included the level sensor?

When I click on the "Make Sure It Fits" dropdown box for my 97 Auroral, the notes say: "Notes: REQS RETAINER WHEN REPLACING TANK RETAINED BY NUT/WASHER ASM WITH SENSOR". I can't figure out what that means! There is no 'retainer' that I'm aware of. Just 2 screws that fasten the tank to the car body. I suppose the level sensor has to be included. What are they trying to say about a NUT/WASHER?

I'll order the coolant tank, and see if it fixes the hissing, and coolant seepage.

I'm still afraid that the head gasket is leaking, and creating pressure above 18psi, and then the cap is venting it. But the engine temp should keep going over 220, like it was before? So far I've driven 100 miles, and it's staying under 220.

I suppose a new coolant tank will answer that question.

mnalep
10-07-10, 02:10 PM
I ordered the new coolant tank. Should get it next week. Sure would be great if that is the problem.

I'd like to try that cylinder leak down test, but my air compressor is giving me shocks. Must have a short? Maybe I'll go to Harbor Freight and buy one, along with a spark hole adapter kit.

Maybe I'll try to find the parasitic leak that is draining my battery down every 3 days.

mnalep
10-07-10, 02:11 PM
Ooops

Submariner409
10-07-10, 05:36 PM
I ordered the new coolant tank. Should get it next week. Sure would be great if that is the problem.

I'd like to try that cylinder leak down test, but my air compressor is giving me shocks. Must have a short? Maybe I'll go to Harbor Freight and buy one, along with a spark hole adapter kit.

Maybe I'll try to find the parasitic leak that is draining my battery down every 3 days.

I thought your coolant test was negative - so your head gaskets should be OK. That tank runs at 18 psi - that's quite a bit of pressure - remember that 30 psi holds the car up on 4 tires.........the new tank will come with the level sensor.

You might get to the PorterCable tools site - every now and then they offer a small 6 gallon pancake compressor and hose/fitting kit for $129. I have one - NO, it's not a HD shop compressor, but it's great for small stuff - tires, cleaning parts, that sort of stuff.

mnalep
10-07-10, 11:41 PM
sub,

I'll look into that.

But what test are you referring to when you by 'coolant test was negative'?

Submariner409
10-08-10, 10:57 AM
But what test are you referring to when you by 'coolant test was negative'?

You're still trying to do pressure tests and such - I thought that, way back on the first page or so, you did a coolant test for exhaust gas and it came up OK ??? (negative result = no gas products)

(EDIT: Yep, Post #1. Block test. No color change. Head gaskets good.)

mnalep
10-08-10, 01:14 PM
OK, test the block fluid test for gases appears to be negative. I say 'appears' since the fluid changed from deep blue, to a light blue. I've been overheating and battling this cooling system for so many months - and fearing a head gasket leak - that I can't let go of that fear, and feel the need to confirm. That is why I was talking about doing that cylinder leak down test - to absolutely confirm.

Since I have hissing, and seepage of coolant, and even on some days pressure release the next morning after cooling overnight - I still have a worry about that head gasket.

I've done so much, I just wanted to be sure I understood your question. Also wanted to make sure that you were not thinking of another test I should be doing.

Also had some folks here thinking I had a head gasket issue even after that test appeared negative. This car is making me paranoid.

Submariner409
10-08-10, 05:31 PM
One stuck piston ring, one valve with a microscopic nick at the seat and your cylinder leakdown test will give you gray hair. Your block (coolant) test said your engine was OK. If it floats your boat, do it again. If that fluid doesn't turn green, or worse, yellow, then you're still OK. You posted that you did the test for 6 minutes: totally unnecessary time and you probably falsely skewed the test. The directions say "2 minutes". Why try to outguess the tool manufacturer ?

Have you replaced the coolant reservoir (that distorted seal lip.......) yet ?

Once again: Failed head gaskets don't cause barely audible hissing and coolant seepage: they cause rapid overheating, false boiling and excessive, rapid loss of coolant as the cap pressure spring vents off system pressures way above any 16 or 18 psi.

mnalep
10-08-10, 08:42 PM
The coolant tank is on order. The estimated delivery date is 10/12/2010.

I was using the block coolant test liquid longer than the 2 minutes, because I thought the longer exposure would eventually turn the color yellow, in case I was doing something wrong, or maybe even got some bad test fluid.

Thanks for the encouragement.

mnalep
10-12-10, 10:31 PM
So, I have the new coolant tank installed, and I am still getting that hissing, and coolant venting from the cap. No Joy!

Video is below. You an just hear the hissing in the first half of the video:

http://s926.photobucket.com/albums/ad107/mnalep/Aurora%20Coolant%20cap%20pics%20and%20Hiss%20video/?action=view&current=MVI_0214.mp4

Clickable image of same video is below:
http://i926.photobucket.com/albums/ad107/mnalep/Aurora%20Coolant%20cap%20pics%20and%20Hiss%20video/th_MVI_0214.jpg (http://s926.photobucket.com/albums/ad107/mnalep/Aurora%20Coolant%20cap%20pics%20and%20Hiss%20video/?action=view&current=MVI_0214.mp4)

And 2 pics below of the new coolant reservoir, where you can see the 'green' coolant has vented onto the coolant tank:

http://i926.photobucket.com/albums/ad107/mnalep/Aurora%20Coolant%20cap%20pics%20and%20Hiss%20video/IMG_0212.jpg
http://i926.photobucket.com/albums/ad107/mnalep/Aurora%20Coolant%20cap%20pics%20and%20Hiss%20video/IMG_0212.jpg


http://i926.photobucket.com/albums/ad107/mnalep/Aurora%20Coolant%20cap%20pics%20and%20Hiss%20video/IMG_0211.jpg
http://i926.photobucket.com/albums/ad107/mnalep/Aurora%20Coolant%20cap%20pics%20and%20Hiss%20video/IMG_0211.jpg

This is just not good!

What do I try now?

Submariner409
10-13-10, 09:18 AM
I'm stumped. This is a real head scratcher.

Again - how much coolant is in that reservoir - cold ?

When you made that video how hard was the top radiator hose ? In order to vent off an 18# cap that hose must have been like a baseball bat.........

mnalep
10-13-10, 01:35 PM
Sub, I am beyond stumped.

Anyways, when I took the coolant cap off today, there was a little more that vented, just for like 2 seconds this time, where before it was venting for like 10 seconds or more.

I also saw something this time that I had not seen before - 2 or 3 air bubbles rose from the bottom of the coolant reservoir, as if escaping from the tube that is attached to the bottom of the surge tank. This tube is a 1" rubber hose, that feeds coolant to and from the engine.

I don't know what to make of that - maybe trapped air?

The coolant level was a bit over the FILL COLD line (maybe .25 inch) - so I tooks about 6 ounces of coolant out.

I did not check the upper rad hose this time, but on past occasions when I've stopped driving - it has been very hard. Not quite baseball bat hard, I could squeeze a little bit - but a very little bit. I will verify again today.

I also reversed the rubber washer on the inside of the coolant cap - just to make sure the rubber gasket is going to form fit to the new tank (not the old tank's indentations).

I am going to drive it again today to see what happens.

mnalep
10-14-10, 04:17 PM
Bad news. I think it is a head gasket leak!

I went to NAPA, and got their BLOCK TEST FLUID. I figured maybe the stuff from AutoZone was not reliable. (A good guess I think).

The stuff from NAPA turned GREEN. And it took about 15 seconds - while the engine was COLD!

Below is the pic of the BLUE fluid in the bottle, and in the test container:
http://i926.photobucket.com/albums/ad107/mnalep/Block%20test%20fluid%20indicates%20head%20gasket%2 0leak/IMG_0228.jpg

http://i926.photobucket.com/albums/ad107/mnalep/Block%20test%20fluid%20indicates%20head%20gasket%2 0leak/IMG_0228.jpg


Below is the BLUE test fluid before testing (in sunlight):
http://i926.photobucket.com/albums/ad107/mnalep/Block%20test%20fluid%20indicates%20head%20gasket%2 0leak/IMG_0216.jpg
http://i926.photobucket.com/albums/ad107/mnalep/Block%20test%20fluid%20indicates%20head%20gasket%2 0leak/IMG_0216.jpg

Below is the pic of the fluid TURNED GREEN in the bottle, after testing for about 30 seconds:
http://i926.photobucket.com/albums/ad107/mnalep/Block%20test%20fluid%20indicates%20head%20gasket%2 0leak/IMG_0217.jpg
http://i926.photobucket.com/albums/ad107/mnalep/Block%20test%20fluid%20indicates%20head%20gasket%2 0leak/IMG_0217.jpg

Below is a pic of the GREEN color (after test) vs, original BLUE color(in bottle):
http://i926.photobucket.com/albums/ad107/mnalep/Block%20test%20fluid%20indicates%20head%20gasket%2 0leak/IMG_0224.jpg
http://i926.photobucket.com/albums/ad107/mnalep/Block%20test%20fluid%20indicates%20head%20gasket%2 0leak/IMG_0224.jpg

One more pic of the GREEN color (after test) vs, original BLUE color(in bottle):
http://i926.photobucket.com/albums/ad107/mnalep/Block%20test%20fluid%20indicates%20head%20gasket%2 0leak/IMG_0220.jpg
http://i926.photobucket.com/albums/ad107/mnalep/Block%20test%20fluid%20indicates%20head%20gasket%2 0leak/IMG_0220.jpg

This is a pic of the BLOCK TEST FLUID from NAPA (On the left, with me pointing at it) vs. the BLOCK TEST FLUID from Autozone(which didn't really work for me):
http://i926.photobucket.com/albums/ad107/mnalep/Block%20test%20fluid%20indicates%20head%20gasket%2 0leak/IMG_0233.jpg
http://i926.photobucket.com/albums/ad107/mnalep/Block%20test%20fluid%20indicates%20head%20gasket%2 0leak/IMG_0233.jpg

I guess I should get my money back from Autozone for the unreliable Block Test Fluid!

What do I do now???

Submariner409
10-14-10, 06:32 PM
Well, dog poo !!!

"What do I do now?"............flip a coin and ask yourself if you want to be in the Northstar head gasket replacement business - either in your garage or that of a shop..............If your car is clean and looks good, it's worth saving. Not cheap, but worth it.

mnalep
10-14-10, 09:51 PM
So it HAS to be a headgasket - right?

That is - it can't be anything else that is causing exhaust gas in the cooling system?

My car is 1997 and 167,00 miles - but I've put so much into it in the last few years. (New plugs, wires, coil packs, fuel pump, water pump, radiator, heater hoses, rad hoses, coolant tank, cap, rear shocks, battery just a week ago, tires are 2 years old, fuel filter, front rotors and brake pads, read brakes, recent fuel rail recall done, and possibly some other stuff that I can't remember at the moment).

It has very little rust. Paint job is fading. But is nice black exterior and tan interior, also showing some wear.

If I believed I could do it myself - I'd try to. But I have no hoist, and probably some other equipment/tools I'd need to get. And it's almost November here in Michigan.

I'd put $1500 into it if I knew that with the head gasket fixed I'd get two, or more, years out of it (trans, etc.). I'm not sure how much over $1500 I'd go...

I don't think I'd get a used car with so many new parts/maintenance on it - and so nice to drive. And the car is not worth much as is.

mnalep
10-15-10, 12:19 AM
What I don't understand is why has it not overheated the last 3 times I drove it?

Ranger
10-15-10, 12:10 PM
So it HAS to be a headgasket - right?

That is - it can't be anything else that is causing exhaust gas in the cooling system?
Correct. The only way exhaust gases get in the cooling system is from a bad HG.

tateos
10-15-10, 03:33 PM
What I don't understand is why has it not overheated the last 3 times I drove it?

Why? Because you probably have more than one head bolt not holding full tension, but you still have some clamping pressure, so depending on the circumstances of the drive, you may or may not get massive expulsion of coolant by combustion gases and subsequent overheating.

I don't think $1,500 is going to do it, even if you do it all yourself. since as you say, you would need to buy some things like an engine hoist. That car, with 167K miles on it, is not worth the repair, unless you like the car enough to fix it and drive it for awhile. I did the HG repair on my '97 ETC at 144,700 miles, not because I needed the car or could financially justify the ~$2,000 I spent to do the job, including new/specialty tools - I did it because I had owned the car since new and it was in pretty good shape overall (it's been in the AZ desert since 2001), I still drive the car today - gone about 19K miles with the new HG. Since the repair, I've had to replace the parking brake release vacuum motor, the water pump tensioner pulley, and the fuel pressure regulator - that's it. Not perfect, but less that $100 cost (just parts - I did the repairs myself) for 2 1/2 years driving pleasure, so I'm glad I did the repair.

To address your other question, the only way for combustion gases to enter the cooling system is NOT just from blown HG - it could also be caused by a cracked block, cylinder liner, or head, but those things are almost unheard of in a Northstar. I would only look in another direction if, when you disassemble the engine, all 20 head bolts "snap" loose when loosened and there is absolutely no sign of leakage on the head gaskets.

mnalep
10-16-10, 04:37 PM
Tateos, Thanks for that info. I am going to start looking to see if anyone near me does this for a price I can justify.

Anyone near Detroit area do this?

mnalep
10-21-10, 10:40 PM
I no longer can perform 'edit this post' function on my posts in this thread? I am logged in!

Anyone know why? sub, tateos, can you guys still edit posts in this thread? I can in my other thread.

STSS
10-22-10, 09:05 AM
I think they lock after a certain amount of time (24 hrs?)

Submariner409
10-22-10, 11:34 AM
I no longer can perform 'edit this post' function on my posts in this thread? I am logged in!

Anyone know why? sub, tateos, can you guys still edit posts in this thread? I can in my other thread.

EDIT ability expires after a period of time. You gotta be quick to CYA.....:sneaky:

mnalep
10-22-10, 01:02 PM
STSS, Sub,

Thanks - I didn't realize there was an expiration on editing older posts!

Ranger
10-22-10, 02:12 PM
If you need something edited I can do it for you.

mnalep
10-22-10, 06:30 PM
Ranger, I'm OK. I just got confused because the PC had just updated windows, and thought it changed a setting somewhere, but thanks.

mnalep
10-25-10, 10:38 AM
Jake, Here are the pictures of my 1997 Aurora you asked about. It is far from mint, but I've done a lot of mechanical maintenace. I was hoping to fix the body up this year, but head gasket, and battery problems got my attention instead...

http://img199.imageshack.us/img199/1500/img0084zq.jpg

http://img513.imageshack.us/img513/6265/img0089r.jpg

http://img835.imageshack.us/img835/5499/img0090b.jpg

http://img543.imageshack.us/img543/1134/img00871.jpg

http://img525.imageshack.us/img525/4250/img00861.jpg

http://img34.imageshack.us/img34/5247/img00881.jpg

http://img204.imageshack.us/img204/7259/img0085marked.jpg