: It overheated again - any idea why?



Lebowski
10-29-08, 09:15 PM
My '99 STS overheated again today. It did the same thing a couple of weeks ago. When I checked the oil it was 3+ quarts low so I changed the oil and put in some fresh Dexcool. I drove it a few times since then with no problems but only for a couple of miles around the neighborhood. This afternoon I drove it 20 miles into Louisville and it overheated a couple of miles from my destination so I just drove it the rest of the way there. After letting it sit for an hour my 2 brothers-in-law looked at it and one thinks it's the thermostadt and the other thinks there's air bubbles in the cooling system. Could it be either of those things? It took half a gallon of water and there were a lot of bubbles coming up through the top of the surge tank when he squeezed the bottom radiator hose when the engine was running. After 15 minutes the temp gauge went up to the H so we shut it off. Should I remove the thermostadt and drive it home without it and see what happens? I don't want to take it to the dealer and blow several hundred dollars letting them fix it. Thanks in advance for any suggestions....

misfit6794
10-29-08, 09:36 PM
Headgasket.

Ranger
10-29-08, 09:49 PM
It could be either, but since it is using coolant AND overheating, have the coolant tested for exhaust gases. You can get a kit at most auto parts store, but don't do it right after adding coolant. I have a feeling it is going to cost a LOT more than a couple of hundred to fix it.

Destroyer
10-29-08, 11:04 PM
Thermostat and simple stuff is what anybody not familiar with the inherent problems of these cars always think it is. I did the T-stat, water pump, etc. The end result is usually HG. Sorry.

ted tcb
10-29-08, 11:48 PM
Not to be a killjoy, but what everyone here doesn't want to tell you is that a Northstar headgasket repair will
run past $3000 .... as the car sits now, it's worth pretty much nothing.
I'd take Ranger's advice and hope no exhaust gasses are present.

Destroyer
10-30-08, 01:18 AM
Not to be a killjoy, but what everyone here doesn't want to tell you is that a Northstar headgasket repair will
run past $3000 .... as the car sits now, it's worth pretty much nothing.
I'd take Ranger's advice and hope no exhaust gasses are present.I woulda told him if that was the question. :D Its a damn shame cause they really are nice cars. The equivalent to going home with Jessica Alba only to find she's a man. :annoyed:

misfit6794
10-30-08, 08:46 AM
Or that shes got herpes.


I paid 3600 for my engine to be fixed after the majority of my headbolts decided they would like to be out of the block.

Lebowski
10-30-08, 02:33 PM
have the coolant tested for exhaust gases. You can get a kit at most auto parts stores

I called 4 auto parts stores including NAPA and also the parts dept. at a Cadillac dealership and none of the 5 people I talked to ever heard of a kit that tests the coolant for exhaust gases to determine if the head gasket is bad. Can I have some specific info regarding this kit and also the cost? Thanks....

zonie77
10-30-08, 03:00 PM
Try a radiator shop. They do it quickly and inexpensively, and they do it more often.

Mark C
10-30-08, 03:48 PM
Heres one on Ebay;

http://cgi.ebay.com/UVIEW-560000-Diesel-Gas-Combustion-Leak-Tester-Kit_W0QQitemZ120319001082QQcmdZViewItem?hash=item1 20319001082&_trkparms=72%3A1420%7C39%3A1%7C66%3A2%7C65%3A12%7C 240%3A1318&_trksid=p3286.c0.m14

Lebowski
10-30-08, 04:00 PM
Thanks for posting that. So it's $60 with shipping and there's enough for 16 tests? Does anyone know where I can get enough for one test for under $10 with shipping? I don't have that kind of money to burn. Or, better yet, would anyone like to buy a very clean '99 STS with 114K miles on it for $3900? I bought it in November 2007 for $7500. I must have been :cookoo::cookoo::cookoo: to buy a late model Cadillac....:(

tateos
10-30-08, 04:04 PM
Save yourself the cost of the kit - it is the HG. Now you have to decide if you like the car enough to spend a lot of time and/or money on the repair. I did it, on my '97 ETC and I'm glad I did, but it's really up to you. These cars have depreciated to the point where it's sometimes hard to justify, purely on a financial basis

Ranger
10-30-08, 04:18 PM
http://www.arrowheadradiator.com/head_gasket_or_combustion_leak_test.htm

Lebowski
10-30-08, 04:21 PM
My wife already told me we're not spending that kind of money to fix it. The worst part is last November I talked her into letting me buy it (for $7500) when we didn't really need it. Now I look like the world's stupidest jerk and she's furious with me. I need to get rid of it ASAP because her employer is cutting back and she may lose her job in the next couple of months and, as you can see in my signature, I already have 3 other vehicles not counting her Honda Insight....:confused::confused::confused:

misfit6794
10-30-08, 06:48 PM
Well the bad news is that the most you will probably get for it is around 1000 bucks. I've never seen a caddy with a shot hg sell for anywhere near 3900.

Lebowski
10-30-08, 08:58 PM
The chrome wheels with an almost new set of low profile tires have to be worth close to a grand alone. I'm going to remove the thermostat this weekend. If that doesn't help I've got a tip on some sealer that might work. What have I got to lose?

zonie77
10-30-08, 09:36 PM
I would advise against sealer in a can. They don't work on N*s and they clog up the cooling system. If you decide to have it fixed properly the cooling system will have to be cleaned out and not just a flush!

Ranger
10-30-08, 10:04 PM
Now I look like the world's stupidest jerk and she's furious with me.
Don't feel TOO bad. Anytime you buy a used car you take a chance. The only guarantees are with new cars. It's called a warranty and comes with a price. Not saying you shouldn't feel bad, just don't beat yourself up too much.

Lebowski
10-30-08, 10:48 PM
I've bought dozens of old cars over the years and obviously have had better luck with some than with others. I bought my truck in December of 06 with 2 miles on it but it was a LOT cheaper than the $53K my Seville cost new in 1999.

If the K&W sealer works I'll have the car up for sale really fast. If I ever buy another Cadillac it'll be a '59 like the light blue 2 door I had a few years ago....:yup:

Lebowski
10-31-08, 03:21 PM
I went and got it today. I drove it home 20 miles on the interstate and the temp gauge stayed at the normal halfway point until I got off the offramp half a mile from my house. Then it started going up fairly quickly but by the time I parked it in my driveway it was only about 3/4 of the way to the H. I cruised at 75-80 most of the way with no problem. It smoked a little for the first half mile or so and then it stopped smoking and ran great. Is that any kind of a hint if it's the thermostat or the head gasket? I'm going out now to try to remove the thermostat. I have to remove the air cleaner assembly first. At least I have the factory shop manual so that should help a little...

Lebowski
10-31-08, 06:01 PM
I replaced the thermostat and it still overheats. My next step will be to try one of those sealants. Hopefully that will solve the problem....

dkozloski
10-31-08, 06:10 PM
I replaced the thermostat and it still overheats. My next step will be to try one of those sealants. Hopefully that will solve the problem....
All you're going to do is create more problems for yourself but there are those people that can't learn any other way.

tateos
10-31-08, 07:56 PM
Don't waste your time or money on the sealer. The sealers might work if the coolant is going into the combustion chamber or lubrication system - maybe - but your problem is the combustion gases are going into the cooling system. If you don't like the car enough to repair it or pay someone else to repair, pull the plug now.

Lebowski
10-31-08, 07:58 PM
I've read a lot of positive testimonials for K&W Block Sealer and, unlike kozloski, I'm an optimist. Since I don't have $3000 to spend having the head gasket replaced I'll spend $16 on 2 cans of that and hope it works for me too....:yup::yup::yup:

zonie77
10-31-08, 08:46 PM
My niece had her HG's go last winter in Chicago. Against my recommendation they tried block sealer. Did not work. After getting the HG's repaired they wound up spending extra to get the cooling system cleaned. As I said before, it was not just a flush. That stuff kept clogging the system and it cost hundreds extra to get it cleaned out.

Do what you gotta do.

Since you have all those cars do you work on them yourself? While it's a long job you can do the HG's yourself and keep the car.

dkozloski
10-31-08, 09:16 PM
I've read a lot of positive testimonials for K&W Block Sealer and, unlike kozloski, I'm an optimist. Since I don't have $3000 to spend having the head gasket replaced I'll spend $16 on 2 cans of that and hope it works for me too....:yup::yup::yup:
You can find testimonial letters for block sealers, oil additives, gas savers, intake tornados, UFOs, astrology, and crop circles. The problem is that they are all written by the same people.

Submariner409
10-31-08, 09:51 PM
To compound the proposed "fix" is that he doesn't realize that the problem is not coolant leaking into the oil or, primarily, the combustion chambers. The problem is exhaust gas blowing into the coolant passages (block liner deck reliefs) so the potential "sealer" is being blown out, not sucked in.

TANSTAAFL. Fix the mechanical problem first.

Ranger
10-31-08, 09:54 PM
It won't work, but I understand where you are coming from. "Repairs in a bottle" are also know as "hope in a bottle". Good luck and keep us posted.

Lebowski
10-31-08, 11:08 PM
This is from the sticky above on Northstar headgasket failure....:D


Mine is a 97 @ 89,000. I bought it with the bad HG and fixed it. I had a 96 that started acting up at 145,000. Did a K&W job and it was holding fine for over 15,000 miles until a soccer mom broadsided me.

Ranger
10-31-08, 11:35 PM
Hard to believe. Maybe it wasn't a blown head gasket in the first place and was misdiagnosed. Give it a shot and let us know what happens. Good luck.

Lebowski
11-01-08, 11:02 AM
I did a Google search for "K&W Block Seal" (in quotes) and read a lot of positive testimonials including one from a guy with a T-Bird who said he drove the car for 5 years after using it with no problems....

Submariner409
11-01-08, 12:00 PM
Seems as if you're going the block sealer route so it's simple from here on out: Pour the stuff in the upper hose or wherever the manufacturer says, fill up and drive. If it works, fine. If not, not so fine.

But............come back in a few weeks and let us know, pro or con.

(Good luck.....)

dkozloski
11-01-08, 06:42 PM
The problem with Northstars is not with the HG blowing. The problem is with the headbolt threads letting go and the head lifting. There is nothing you can add to the radiator that will repair this.

ghutchin
11-17-08, 01:26 PM
Why would you even consider adding junk to your engine before you have diagnosed the problem. Unless I missed something, I don't think you ever confirmed that it was a HG issue. Perform the block test to determine if there is exhaust gas in the coolant. Napa has a kit for $50. The part number is BK-7001006 and it is called Leak Detector Kit / Engine Block.

On a side note. Did you check your coolant bypass line to see if it is clogged. I had a similar issue recently which I thought was a HG issue. Turned out the bypass was clogged. I even seemed to be loosing coolant. I think it was just bubbling out when the car was running hot and I didn't notice it.

Regardless of the issue, diagnose the problem before attempting to fix it. You will save a lot of money and frustration in the end.

Destroyer
11-17-08, 09:26 PM
If the K&W sealer works I'll have the car up for sale really fast. I understand your frustration as I went through this as well. I decided to get rid of mine and I could have sold as not having the H/G problem cause it would start up and drive fine until it got to operating temperature. Morally I just couldn't bring myself to that. Selling the car and knowing it has this fatal problem without disclosing it is just plain wrong. Yeah, I had $8k into my '98 Deville cause I did a lot of repairs and added some custom touches and I only got rid of it for $1600 fully disclosing the problems it had. Had it 1 year and put almost exactly 10k miles on it. I dont think I could have slept at night knowing I screwed someone by selling them a broken car and not telling them. Look at what it has done to you, why pass it on to someone else?. Pisses me off too cause what I didn't know is that I sold mine to a dealer (came to my house as a private buyer) and 1 week later I saw it on his lot. Guess the ole' Deville lived enough to screw another buyer. Upside is that the dealership which was in business for over 15 years went out of business within 6 months of buying my car. I know it wasn't because of my car but it made me feel warm and fuzzy inside knowing that he was out of business.

97EldoCoupe
11-20-08, 12:09 AM
Hey Lebowski - come on over to Canada. I'm 487 miles from you. $1250 and your car will be cool as a cucumber even when you pass someone doing 100+MPH.....
I've done the HG's on over 40 Northstars to date, no failures. I beg you, don't add that coolant system sealer. I've seen too many times what it does.

If you want to mapquest me, type in "N0J 1Y0, Canada".

Lebowski
11-20-08, 04:40 PM
My daily "commute" is a 9/10 mile drive to the post office every day. (I'm a full time Ebay Power Seller and I work out of our house.) I've been driving it every day there and back with no problems because it doesn't get hot enough to overheat. I guess I'll just keep doing that and will use my 07 Chevy pickup or my wife's Honda whenever we have to go anywhere farther than 5 miles. I'm still not sure if it's a head gasket or water pump problem. I'm not going to sell it without having it fixed or disclosing the problem to a potential buyer....

Krashed989
11-20-08, 09:08 PM
The ONLY way I can see that sealer working is if you put it in, run the engine to get it all mixed thoroughly, then pressurize the cooling system (engine off) so you reverse the leak to go into the cylinders and seal the gasket. Otherwise, it's probably a waste of time.

Submariner409
11-20-08, 10:29 PM
The downside to that idea is that the cylinder pressures in the combustion cycle are on the order of hundreds (thousands ?) of psi, while the coolant is pressurized to 18 psi.

Which way will the gas go ??

neverstuck
11-21-08, 03:21 PM
there is no magic cure to the hg problem ..Ive seen everything tried over the years n* and others ,you might get a week or 2 ,maybe a month but it is not fixed at all

RickyHenry
11-27-08, 02:00 PM
Or that shes got herpes.


I paid 3600 for my engine to be fixed after the majority of my headbolts decided they would like to be out of the block.

wow, I love the way you phrased that, very funny. :thumbsup: