: New '98 Deville Owner with coolant questions



olsonscottm
01-11-09, 10:51 PM
Hello All,
New to the group, and new to Cadillac ownership.
I just picked up a 1998 Deville with 128K miles on it. Runs and drives great, with the exception of steam coming from under the hood. Not a lot, but a little. I bought the car, drove it 50 miles home, and could smell antifreeze.

I changed the oil and filter, reset the oil life indicator and fired her up. I got the "Check Coolant Level" message in the DIC. I added about 1/2 to 3/4 of a gallon of Dex-cool and went for a drive. When stopped, I could see a small amount of steam coming from under the hood on the left side. It was cold, about 5 deg. F. There isn't any puddling under the car, so I'm not sure where the coolant went.

I've read quite a bit about the car the last couple of days (thanks to all who participate in this forum, it's been very educational!) and hope it isn't the proverbial head gasket. Temps stay right between 210-220. I haven't seen anything hotter than 219.

My questions are: 1- Will a pressure check tell me if it's a head gasket? If not, will it show me where the leak is coming from? How do I check the water pump? How would I change the radiator? Pull the front bumper and all that stuff under the front of the hood?

Also, when I changed the air filter, I forgot to plug the air sensor back into the box, fired up the car and went for a 10 mile drive and the "Service Engine Soon" light came on. Once I plugged in the airbox sensor, I thought it would go away, but the light is still on.

Well, I've talked too much, but would like to thank all who participate for the benefit of others that you haven't met, it is appreciated.

Thanks, I'm looking forward to many, many miles in my new-to-me Cadillac (my first).

Scott
Palmer, AK

Ranger
01-11-09, 11:20 PM
Destroyer will guarantee you that it is a head gasket, but he is a malcontent so ignore him. Head gaskets rarely if ever leak externally. If it is on the left side it most likely is a water pump, but could also be a hose or radiator side tank. Watch more closely to pinpoint where it is coming from. Use an inspection mirror and a flashlight to check the pump shaft seal behind the pump pulley. First find out where it is leaking from, then we'll help you fix it.

A cooling system pressure test will usually not diagnose a head gasket leak, but will locate a cooling system leak as the leak will eventually drip and not evaporate.

You can enter the diagnostic mode to clear the DTC stat set the SES light or wait for 3 ignition cycles after you plugged the sensor in. 3 cycles with no fault detected will send the DTC to history and turn off the light.

olsonscottm
01-11-09, 11:26 PM
Ranger,

Thanks for the info. I just read another post that said to feel the inside of the tailpipe to see if it's slimey or not. So, I went and checked my tailpipes, and no slimey, just the usual black soot.

Now, how do I enter the diagnostic mode to clear the DTC Stat Set? (if it's already been covered, can you point me to the post?)

Ranger
01-11-09, 11:42 PM
Go to the Tech Tips section and see the sticky at the top.

You DO NOT have a head gasket problem. Like I said, they almost never leak externally. If you where loosing coolant with no external leak, then it would be suspect.

dirt_cheap_fleetwood
01-12-09, 02:53 AM
If it is not a headgasket issue and you do not see any puddling under the car and it is steaming than the leak is most likely near the top of the engine. The coolant is probably dripping onto the hot engine and evaporating/boiling off. Check the coolant return hose at the top of the engine for signs of wear/cracks/dry rot and replace as necessary.

olsonscottm
01-12-09, 03:55 AM
I'm gonna have it inspected in the next day or two, but we found an auto shop invoice in the back seat, dated 11 days before we bought the car that states "over 1200 hydro carbons in cooling system witch show blown head gaskets and or cracked heads!! recomend engine replacement. note water pump housing is leaking also."

We'll see what a second opinion gets us.

Ranger
01-12-09, 11:34 AM
Well that's not good. Save that invoice. That is good evidence that they knew of the condition and did not tell you should you decide to try for a refund. I still find it hard to believe that a head gasket is leaking externally unless you have 2 seperate conditions as the invoice seems to suggest.

olsonscottm
01-12-09, 01:28 PM
I took it to a shop today, and the guy that can do the testing is off on mondays, so I have to wait until tuesday.

I'll let them check it out and see what they say.

The external leak may in fact be the water pump. If it is, I think I can tackle that repair myself. I'm no pro, but do know my way around an engine.

If the head gasket is in fact leaking, I'm presented with a quandary: do I suck it up and replace the engine, or try and fight to get my money back. I paid $2600.00 for the car (first clue should have been the low price, I guess) so by the time I add an engine in for who knows how much, is it worth it?

I found a place that will sell me a reman. 4.6L for $3250, plus $600 for shipping. I don't know if I can swap this engine or not. I only have a two-car garage, and don't know if I have room to drop the engine and pull it out.

Anybody know how much time it takes to swap one of these? Am I better off with a new engine for $4K, or getting a used one?

Thanks all, and especially Ranger.

dirt_cheap_fleetwood
01-12-09, 01:43 PM
If you can have the head gaskets repaired do that over an engine swap. HG job usually costs between $3500 and $4000 and it will cause far less problems than an engine swap may cause. These cars are very technologically advanced pieces of machinery and they do not like when things change. Like Ranger said, use the invoice as evidence and try to get a refund for the car. I am sure there are laws in your area designed to protect consumers from this kind of thing so use them to your advantage.

misfit6794
01-12-09, 01:48 PM
What was the date on the invoice? If it was from awhile ago, they may have had the hg's fixed, but I think they would have asked for money for the car if that was the case. That invoice could be your ticket out.

You can buy the kit that tests your coolant and will show you a hg problem at napa, i think its like 50 bucks, its just some strips that change color, I'm not sure why your mechanic needs "a guy" for that.

Take it out on the highway and see what it does, if it overheats (250-260+) theres a good chance its hg's , or you wil definetly see an external leak. Just bring some coolant with you.

olsonscottm
01-12-09, 01:58 PM
I bought the car on 1-10-09, and the invoice (which shows one hour shop time) is dated 12-29-08. So I think they knew, didn't disclose it, and we wouldn't have known if not for finding the incriminating evidence.

When I suggested an engine swap, I meant replacement. If you've got to pull the engine out to change head gaskets, why put an engine with 128K miles back in?

I drove for about an hour at 60-65 mph and didn't see temps above 215. Runs fine, lots of power.

I'm not sure if the mechanic wants to just run that test, or actually do a cylinder leak-down test, or some other kind of test.

I know my way around a 350, even rebuilt a couple back in high school, but this is much more complex and don't know if I should even try tackling it.

Ranger
01-12-09, 02:34 PM
I would not replace the engine for a head gasket. Especially with a used one. Never know if that one will go. If you are going to attempt this yourself, there are several people here who have done it and have written some very good tutorials on doing it. Check the Tech Tips section. Might also want to contact 97eldocoupe (Jake). http://www.cadillacforums.com/forums/northstar-performance-technical-discussion/153232-northstar-repair-without-inserts.html

Destroyer
01-12-09, 08:22 PM
Destroyer will guarantee you that it is a head gasketHow'd you know?:D

Ranger
01-12-09, 08:30 PM
Your reputation precedes you.

buckeyemerritt
01-12-09, 08:50 PM
This board is full of a lot of great information but will totally freak you out about the dreaded HG issues these cars have.

Maybe I am confused but as I have read the thread I have not seen that your car has overheated, am I wrong?

The most concerning thing in the invoice.........

I have a 96 Deville and I thought for sure it fell to the HG monster as it would overheat on the freeway when I would go over 60 mph.

I switched out the cap, thermastat, water pump, belt and tensioner and the problem has not come back, car runs at 70mph at between 196-203 now.

BTW that is one easy water pump to switch out.

Also did you buy from a dealer or private seller?

Laws are much different on what they are required to tell you.

If it is a private seller you might be out of luck as most states do not require private sellers to disclose any defects and all sales done are done "Buyer Beware"

Destroyer
01-12-09, 09:26 PM
Your reputation precedes you.The reputation for "keeping it real" right?:D

olsonscottm
01-12-09, 10:17 PM
As far as I know, the car hasn't overheated. I pulled the trouble codes and didn't get a "P0107 - Manifold Absolute Pressure (MAP) Sensor Circuit Low Voltage" or
"P0108 - Manifold Absolute Pressure (MAP) Sensor Circuit High Voltage."

Doing 65-70 on the highway, temperature running a consistent 213-217. The water pump may be leaking, and I plan on replacing that.

I might also have the radiator tanked, pressure tested - something. So far I haven't been able to find the location of the leak. It is hard to see in there, as I'm sure you all know.

I bought from a private seller, so I don't know what recourse, if any, I have. If I hadn't found the invoice, then I would be none the wiser, but since I did find the invoice, and get an email where I was told there are no mechanical problems or leaks, I have proof I was flat out lied to and that is what is ticking me off.

If it needs head gaskets, I may just go ahead and do that. I was thinking since I was going to have to pull the engine anyway, why put an engine with 128K back in. But, replacing head gaskets is several hundred dollars (doing the work myself, with some friends) vs. several thousand dollars.

Should be inspected tomorrow, I'll post the results when I get them.

Ranger
01-12-09, 10:25 PM
If it needs head gaskets, I may just go ahead and do that. I was thinking since I was going to have to pull the engine anyway, why put an engine with 128K back in.
The head gasket is the weak link. The lower end will last forever. When you open it up you'll still see the factory hone pattern on the cylinder walls. Bearings, rings & cylinders will not need to be touched.

olsonscottm
01-12-09, 11:24 PM
That makes me feel better about just replacing the head gaskets.

I didn't know the bottom end was so durable on these engines.

olsonscottm
01-14-09, 01:28 PM
I had a shop test the coolant yesterday, and they confirmed hydrocarbons in the coolant. They used some sort of hydrocarbon sensitive liquid and tested in a tube, similiar to a pH test, the liquid changed color from dark blue to dark green. If it had changed to yellow, that would have indicated lots of hydrocarbons in the coolant.

The good news, if there is any, is that there evidently isn't that much leaking at the present time, so maybe I've got some time to dwell on possibilities.

Thanks all for the replys, and I'm glad I joined this forum.

Ranger
01-14-09, 03:17 PM
Yeah, you have some time. They generaly start slow and slowly get progressively worse. It will start using coolant and overheating under heavy loads or climbing hills. Then it will start a rough idle at start up and finally start to overheat all the time.

buckeyemerritt
01-14-09, 05:55 PM
Ranger now you got me a bit freaked as my deVille tempartature climbs a bit when under load or up hills.

it generally drive stays around 196-203 cruising 65-70.

Merging onto the freeway it migh go as high as 212 rarely usually 208, on hills it might go to 206.

I always thought this was normal

Ranger
01-14-09, 08:56 PM
Relax, that IS normal. My '97 was a digidash so I could see the temperature and it ran a consistent 206 (summer) to 213 (winter). Reread my post. I said "overheating under heavy loads or climbing hills".

buckeyemerritt
01-14-09, 09:22 PM
Ok got a bit nervous there.

I would think it would run cooler in the winter with the cool air.

Is that not the case?

This is the first Digital Dash I have had and I am a bit nervous about overheating these N* engines.

Ranger
01-14-09, 09:55 PM
That was my thought as well, but when I saw that and questioned our old Guru, he said that it was because during the summer, the thermostat was wide open and during the winter it is only partially opened.

The best thing you can do is set it to MPG and quit watching the coolant temp. It's gonna drive you nuts. 80% of the things you worry about never happen and the other 20% you can't do anything about anyway. Drive it and enjoy it. My neighbor bought my '97 3 years ago at 107K and it is still without problems.

buckeyemerritt
01-14-09, 10:29 PM
To get back to the issue at hand.

I would file against the seller in small claims court.

The filing fee should be a little of nothing and really pretty easy you can research the process on line.

The worse case is you loose the case and might be out $50 and a little time.

You never know with the owners knowlege of the problem anything could happen.

I have seen judges do a lot crazier things.

You might want to contact the seller and give him a chance to make this right before filing.

olsonscottm
01-15-09, 02:52 AM
Buckeyemerritt,

I did a little preliminary research on small claims court in Alaska. The first thing to do is give the potential defendent the chance to make it right. So I sent him an email stating the facts as I saw them. So far I haven't received a response, but it's only been one day.

Next step will be to send a letter certified mail. Once he receives that, I'll give him a couple more days and then probably file in small claims court.

The filing fee for small claims in Alaska is only $40 bucks, so I think it would be worth it. I just don't want the guy to get away with it.

I'll keep you posted, it you want.

Ranger
01-15-09, 03:53 PM
Please do and good luck.

Douglass Harroun
01-25-09, 10:44 PM
I've got a pair of '97 Deville cylinder heads for sale, rebuilt, 40,000 miles, just posted in parts for sale section. Look like new. Not fitted.
Doug

olsonscottm
01-31-09, 02:48 AM
Update...

I haven't filed in small claims court, been too busy with my new job, my second job, and the family.

I have put about 1000 miles on the caddy, and it gets 25 mpg running average, 28-30 on the highway.

I've added just over a gallon of anti-freeze during that time. It runs rough for the first thirty seconds or so, and then just purrs.

Going down the road, it will stay between 203-219 most of the time. Tonight, stuck in traffic on the highway (fresh snowfall, must've scared the wimps) it got to 224 a couple of times, then cooled off to 206. Then, it peaked at 233 once. Kinda scared me 'cause I was moving along about 50 mph, but it cooled down and ran fine the rest of the way home.

I'm hoping I can nurse it until summer and have some more money in the bank.

Sure is nice! One sweet riding car. Heated seats would be nice, though.

Scott,
Palmer, AK

cadillac_al
01-31-09, 07:34 AM
It's just a matter of time before it needs head gaskets. The previous owner knew that and unloaded it. You have an open and shut case to get your money back. I had a friend that sold a vehicle and the engine died shortly afterward. He got sued in small claims court and had to refund the money; simple as that. You have the invoice that verified the engine needs "replacement". You really should get your money back or at least some money back for the head gasket job if you really like the car. Good luck.

olsonscottm
07-27-09, 11:23 PM
Yep, it's head gaskets. I've got the engine out and the left head almost ready to come out. Right now I'm stuck trying to remove the water pump drive pulley without forking over $100 bucks for the "special" tool. Any suggestions?

I hope to have the car back together in two or three weeks. And yes, I've got the stud kit on order, should be here next week.

Scott
Palmer, AK

Ranger
07-28-09, 10:28 AM
That pulley tool is a P/S pump pulley remover. Should be able to pick one up for a lot less than $100.

olsonscottm
07-28-09, 11:38 PM
Right you are Ranger, I lucked out and found a GM power steering pump pulley puller (I love saying that!) and got the water pump drive pulley off tonight.
Next, removing the crankshaft balancer, front cover, and then the left head.
Stud kit will be in sometime next week.
Head gaskets still need to be ordered. Is it worth the extra money to get dealer head gaskets or will Fel-Pro work as well?
Looking forward to getting this thing done, back together and driving my Caddy again.

Scott
Palmer, AK

Ranger
07-29-09, 12:11 PM
I think Jake uses Felpro.

olsonscottm
07-29-09, 11:08 PM
If Jake uses Fel-pro, that's good enough for me.

olsonscottm
09-16-09, 02:42 AM
UPDATE:

Completed the head gasket repair!! Used Jake's stud kit - highly recommended!

But now I have a low oil pressure problem at hot idle. I changed the oil pressure sending unit but the problem persists. Probably bearings. Not sure what to do now. Maybe run 10w40? No oil pressure problems above about 800 rpm's.

Scott
Palmer, AK
1998 Deville

Submariner409
09-16-09, 09:09 AM
Check the torque on the crankshaft pulley: proper torque is essential to assure correct oil pump drive - it's driven by clamping friction of the balancer itself.

The bolt must be torqued to 37 ft/lb and then further rotated 120 degrees. You must lock the crankshaft to get this torque, so remove the flywheel (flexplate) cover under the bottom of engine/transmission joint and use something to lock the flexplate teeth.

olsonscottm
09-16-09, 10:06 AM
When I put the crankshaft balancer back on when the engine was out, I did just that. Actually, I torqued the bolt to 40 ft-lbs and then went the additional 120 degrees.

When I started the engine for the first time, I didn't have any oil pressure so I shut it down. I then removed the right front wheel and splash shield and tightened the bolt another 3/4 to 1 turn, fired up the engine and had oil pressure.

I have oil pressure when cold, and when warm, but after driving down the highway, the light will come on below about 800 rpm. I don't have an oil temperature gauge, but the oil temp has to be in the 150-175 degree range by then.

The car doesn't get hot anymore, so the head gasket issue is fixed. I just hope I didn't fix an engine with bigger problems.

Scott

Ranger
09-16-09, 12:00 PM
I doubt it. You had no oil pressure problems before the HG job. It has to be something you did or did not do. Oil pumps and the lower ends on these engine seem to be very reliable.

Submariner409
09-16-09, 12:56 PM
If you did the original torque sequence, had no oil pressure, then "tightened" the crank dampener bolt another 3/4 turn, something is wrong. You should not be able to turn that bolt 1/4 turn if it was properly done in the first try - you wind up with close to 200 ft/lb of torque there - practically impossible to go any farther without long extensions or a 3 foot pipe on the end of the torque wrench.

Ranger
09-16-09, 02:58 PM
If you did the original torque sequence, had no oil pressure, then "tightened" the crank dampener bolt another 3/4 turn, something is wrong. You should not be able to turn that bolt 1/4 turn if it was properly done in the first try - you wind up with close to 200 ft/lb of torque there - practically impossible to go any farther without long extensions or a 3 foot pipe on the end of the torque wrench.
Not that it makes much difference, but I thought I once heard something like 320. Either way you are right, it should be TIGHT.

olsonscottm
09-16-09, 10:14 PM
The only thing I can think of is that when I put the crankshaft balancer back on I got to 37 lb-ft of torque before the balancer was seated completely. If that's the case, then I can see how I could get more turns out of the bolt.

That may very well mean that I installed it incorrectly. Hard to see how that happened though. I mean, it it's supposed just slide on, put the bolt in the only hole available, and tighten. You'd think if I could do the head gaskets, I could do the balancer.

Any and all thoughts greatly appreciated.

Scott

Submariner409
09-17-09, 09:42 AM
No criticism here, Scott.

That crank bolt is an obscure reason for oil pressure problems in a Northstar, so it's worth a look, which is why I did the entire 37 + 120 shtick.

IF there were a burr on the crank snout or in the balancer bore, then it's entirely possible that 37 ft/lb would be reached before the hub was seated on the oil pump face. You have now probably fully seated the hub, so the hour required to go back, slack off the bolt, and go through the torque sequence may well solve your low speed oil pressure. It's only a recommendation, but it addresses a common problem. There are other possibilities, including an air leak into the oil pump pickup line, but you weren't that far into the engine to disturb that.

Way back in here there were threads on how to overfill the engine to clear a pick up tube air lock from a stuck drainback valve - that also leads to a "no oil pressure" on start because the oil pump is higher than the oil level, it's a gerotor, so must be always primed. No easy answers, just thoughts............

EDIT at 0955. Just saw your other post on the same subject - hope it worked. Tight, huh ?

Submariner409
09-17-09, 03:25 PM
:bump:

Thought I'd put this next to the same question - different thread.

tateos
09-17-09, 08:56 PM
No criticism here, Scott.

That crank bolt is an obscure reason for oil pressure problems in a Northstar, so it's worth a look, which is why I did the entire 37 + 120 shtick.

IF there were a burr on the crank snout or in the balancer bore, then it's entirely possible that 37 ft/lb would be reached before the hub was seated on the oil pump face. You have now probably fully seated the hub, so the hour required to go back, slack off the bolt, and go through the torque sequence may well solve your low speed oil pressure. It's only a recommendation, but it addresses a common problem. There are other possibilities, including an air leak into the oil pump pickup line, but you weren't that far into the engine to disturb that.

Way back in here there were threads on how to overfill the engine to clear a pick up tube air lock from a stuck drainback valve - that also leads to a "no oil pressure" on start because the oil pump is higher than the oil level, it's a gerotor, so must be always primed. No easy answers, just thoughts............

EDIT at 0955. Just saw your other post on the same subject - hope it worked. Tight, huh ?


Yeah - we are of the same mind Sub - that balancer was never seated in the first place.