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1998 STS overheating!


UKcat

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"The car idled for 13 minutes without a sign of any bubbles. Finally, the level of the water in the bottle rose up in the neck and ran over."

This is normal. Straight water, idling for 13 minutes brought your car easily to operating temp and higher, water boils at 212 degrees. Thermostat open, cap off, water boiled, and ran over. I don't see why this is considered a criteria for taking it to the dealer, you are lucky it did not spontaneously boil and EXPLODE out of the reservoir and scald you. If nothing else no bubbles for 12 minutes was a positive. What you should have done was put coolant in the engine at the correct 50/50 concentration and drive it after you 'reverse' flushed it. For future reference, flushing is not recommended, you just introduced minerals from tap water and now its difficult to get a 50/50 mix as you have straight water in your engine.

Why not buy a coolant combustion by products tester at NAPA before running to the dealer?

http://www.napaonline.com/MasterPages/NOLM...2f+Engine+Block

One more thing, I have asked a couple of questions that you did not answer unless I missed it:

1) did you check for codes? Y or N?

2) Is your AC ON or OFF during all of this?

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I did not know how to check for codes until I read it on one of the forums here yesterday.

Yes, the A/C was on when it initially overheated Saturday and Sunday. Also, it was on Wednesday after I put some coolant in the radiator hose. I drove it about 5 miles that afternoon; forgot to put that in the earlier post; it got extremely hot before I got home. That was the day that I got the message about the engine being hot and shutting the a/c off.

My "other car"

100_05472.jpg

1968 Pontiac GTO, 400, 4 speed, 366 h.p., matching numbers car

*Get well soon, John Force!!!*

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Also, this is a two party effort here; I was against taking it to the dealer so quickly; the hubby made the appointment and arranged to have it towed up there against my better wishes :rolleyes:

Reading all of your thoughts on here has only made me more apprehensive; I just do not think it is a head gasket; hope we don't get taken in at the dealer. What scares me more than anything is the fact that they may take it apart and not put it back together properly. The timesert issue scares me; if they don't do that properly, we may be in worse shape that we were to begin with!

I hope they will do some testing that we did not do that will show them a better answer to this problem. It just seems that it should be something more simple.

Also, I asked the hubby, after he had already had it towed, if he had checked the oil since Saturday and he said no. Wish I had thought of that sooner. If it is a head gasket issue, would the oil have had water in it??? I know it probably would have if the head was cracked, but I didn't know if it would show if it was only a minor breach of the gasket.

My "other car"

100_05472.jpg

1968 Pontiac GTO, 400, 4 speed, 366 h.p., matching numbers car

*Get well soon, John Force!!!*

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No, Northstars rarely leak coolant into the oil when a head gasket goes because of it's design. I hate to say it, but your symptoms do not sound good. If it is head gaskets and you have it repaired, insist on ALL 20 bolt holes Timeserted. A competent deal mechanic should not have a problem with this procedure.

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Well......................as I was afraid of...............it is a blown head gasket :( . I was hoping for a one-sided repair to keep the cost down; I guess that is not a good idea; their initial indication is to take both heads off, send them to the machine shop to check for cracks or warpage; new gaskets, timeserts, pellets, coolant, etc.

My question is, is a one-sided job feasible; not a good idea; or what????? Cost estimate right now is $3500.00 for both sides.

The book value on the car in this area is not much more than that. I am not sure I want to put that much money in a '98 model car. Give me your thoughts. Should I do it or forget about it???????????????

I need to give them an answer today. I don't know what to do.

My "other car"

100_05472.jpg

1968 Pontiac GTO, 400, 4 speed, 366 h.p., matching numbers car

*Get well soon, John Force!!!*

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I don't believe that a one sided repair makes sense given that the engine is out, a lot of the cost is in R&Ring the engine/tranny. Plus, whatever caused the one head gasket problem most surely will affect the other, ie, coolant change interval, etc.

As far as the logic of spending $3500 on a 98, what are your alternatives, can you afford a new car? What can you sell this car for needing the head gasket job, as is? What kind of a car can you get for $3500, how much can you add to that? Maybe you can put $3500 down and lease? Only you can answer that question. But, once this job is done your engine will be bullet proof.. make sure they do case half seals.

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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From what I can understand, the engine is not out, yet. They diagnosed the problem through testing (and I don't know what); now they want us to tell them what to do.

I haven't actually talked to the service manager and the hubby is not smart enough to ask enough questions or the right questions. He says I don't know anything about it, and he is right, but I am smart enough to ask questions, to get the answers to the things that I don't know!

In answer to your question, No, we cannot afford to buy a new car at this point. Actually, I have never had a new car. The hubby has a body shop; when we get ready for a car, he trys to find something that does not have major damage, and fixes it himself. The car I have is a '98 STS. It had 19,000 miles on it when we got it in 2000. It has been a wonderful car and I was not ready to get something else. There is not really anything out there right now that I like any better than my car, so we were not even thinking about getting something else. However, I just don't know if it is smart to put that much money in a car that is almost 10 years old.

My "other car"

100_05472.jpg

1968 Pontiac GTO, 400, 4 speed, 366 h.p., matching numbers car

*Get well soon, John Force!!!*

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How did they determine that the head gaskets are shot? Did they do a combustion by-product test on the coolant or pressureize each cylinder with shop air? You need to be certain they properly diagnosed the problem and are not just shooting from the hip that any Northstar that overheats has bad head gaskets.

If the gaskets are shot, do both sides - otherwise, the other side will let go shortly after the engine is back in the car... Murphy's law.

Make sure they warranty the job and follow the Timeserting procedure to the letter - Make sure they do not free hand the drilling operation. The drill fixture MUST be used. Make sure they warranty the repair - if they won't, find another dealer.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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Usually when the head gaskets go in a Northstar the root cause is overage coolant corroding the threads in the head bolt holes, and a head bolt letting go. If that is happening, eventually a head bolt on the other bank will let go. I wouldn't consider a one-sided job.

KHE has the $64 question -- how did the diagnose a head gasket problem?

KHE also has the principal caveat on the Timesert job: make sure that the tech doesn't cut any corners. You MUST use the template and follow all the instructions to the letter, and you MUST use the taps by hand, carefully.

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They did the pressure test, I was told. They will not do just one side; shows how much I know about it. Hey, I am no mechanic!!! They said you must do both sides; from what you fellas have told me, that is true.

We have decided to fix it; we both love the car; just hope something else dosen't go wrong after we get it back!!!

Now, the important part is, I need them to hurry up!!!! We have tickets and reservations for the NHRA drag race in Norwalk, Ohio on the 28th. Going up Thursday, staying till Monday; I need my car back!!! Also, the following weekend, we are going to another drag race in Bristol, Tennessee. It was originally scheduled for the 18th of May; for those of you who follow NHRA, you may know that it had to be re-scheduled. It is now slated to be held on July 6,7,8. That makes us traveling to northern Ohio and eastern Tennesse in one week. Hope my repair job holds up!!! We are in central Kentucky, about 40 miles south of Louisville, so each trip is about 300 miles, one way. I guess we will find out pretty quick if our repairs are successful!!!

I do love the smell of nitro :P

My "other car"

100_05472.jpg

1968 Pontiac GTO, 400, 4 speed, 366 h.p., matching numbers car

*Get well soon, John Force!!!*

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I'd expect that car to be valued at nearly twice the figure you're suggesting, especially considering the business "hubby" is in. Have you done any research?

Or is this a case of the shoemaker's son who had no shoes?

Good luck in any event and watch those tool jockeys like a hawk! I'm guessing you're just the type to do that.

Regards,

Warren

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sorry to hear the outcome is the worse case.

not sure how many times the engine got a FLUSH, but the Prestome is

an acidic product designed to dissolve scales from the cooling system.

i never recommend that in any car younger than 1980 or even older

if the coolant system has been maintained well with no scaling.

problem is the chemical also takes some metal off the headgaskets and

headbolts.

it is too late for you but maybe others will see this and avoid.

do not flush with chemical flushes, ever, unless you got a vintage car

that sat for 10 years and the scales have to be removed. it is like

cleaning bird poop of the paint with a knife - you will remove the bird

poop alright, along with some paint.

curious .. what is the estimate for the headgasket repair?

thanks

I have pretty much stated every thing we have already done. I am not sure exactly when this first started; I think it may have been last fall. One day, while traveling in the eastern Kentucky mountains, the temp. guage went up to about the 3/4 point, which is very unusual. Most time, it never goes past half-way. We stopped for a while; after checking the coolant bottle, it was a little low, so we added some coolant to it.

I will admit that we have not done the recommended coolant changes like this forum states that we should have done; WE DIDN'T KNOW!!!! I don't remember when I first changed the water pump; possibly two years ago; I did flush the system and put in new coolant then, but I did not add the pellets; again, I didn't know!!!

The sudden overheating started last weekend. Twice, after driving about 15 miles, the guage went in the 3/4 level. It was not a false reading; the car was pretty hot; coolant was overflowing from the reservoir bottle on both occasions.

Sunday night, I decided that the thermostat may have been defective, so I got a new one (not Delco) and put it in. I refilled the system and started the car and let it idle about 10 minutes. It reached normal operating temperature and seemed to be o.k., so I drove down our street about two miles and turned around to come back to the house. The temp. guage got in the 3/4 level before I got back home.

Monday, I got a new water pump. I really did not think that it would be the problem, but I figured that I might as well try, so I put it in. Again, I refilled the system, started the car, let it idle about 10 minutes, and drove down the road. Same results; it got hot again before I got home.

Tuesday, somebody suggested that I had trapped air in the system. It does not seem that the radiator hoses get hot; I wondered if maybe the coolant was not circulating properly. I took the uppper hose loose at the fitting and poured some new coolant in the hose so that it would flow directly in to the radiator. I started the car and took the purge line loose at the reservoir bottle. It flows out of the line as it should.

Wednesday, I drained the whole system and reverse-flushed it. I filled it with water and added a Prestone flush product. It states that you are supposed to start the car and let it idle until it reaches normal operating temp. and then drain it out and refill, again, with plain water and repeat the idle process.

When I refilled the system with clean water I took the cap off of the reservoir bottle and watched for bubbles. The car idled for 13 minutes without a sign of any bubbles. Finally, the level of the water in the bottle rose up in the neck and ran over. As it reached the top of the bottle, it made one bubble as it ran over. I did not know if that is what I was supposed to be seeing or not.

We had the car towed to the dealer Friday; they are supposed to look at it Monday. I didn't know what else to do.

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Actually, this is the first time :o that we have actually flushed the system with another product. Before, we just drained it out, and filled with new product. I did not add the pellets then. We did not know about the bulletin or info. that suggested the frequent coolant changes, so this is probably our fault for poor maintenance. The owners manual that came with the car states to change the coolant at 150,000 miles. This is in the maintenance book that came with the car. We were never told anything different. I have talked to numerous guys this week concerning the frequent coolant changes and nobody has ever heard of it either; at least we are not by ourselves in this category!!! I have three friends with northstar engines in their cars; I asked them about their coolant; they have not done any changes either; I told them.............get ready............you're next!

The estimate for repairs that we were given Tuesday was $2800.00, plus the charge from the machine shop to inspect the heads. So, it is pretty close to what you all have suggested. The service manager said they have done the same work on several of the northstar engines; he said it was not unusual. I guess if we had taken it to the dealer for routine maintenance, we may have known about the recommended changes, but we are pretty much do-it-yourselfers; this time it didn't work!

My "other car"

100_05472.jpg

1968 Pontiac GTO, 400, 4 speed, 366 h.p., matching numbers car

*Get well soon, John Force!!!*

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I'd expect that car to be valued at nearly twice the figure you're suggesting, especially considering the business "hubby" is in. Have you done any research?

Or is this a case of the shoemaker's son who had no shoes?

Good luck in any event and watch those tool jockeys like a hawk! I'm guessing you're just the type to do that.

Regards,

Warren

I got my "value" information from the NADA web site. High price ( I think) was $7,000, low was $3500, average was $4500. This is with a $1400 deduction for high mileage. I would not think that 138,000 miles for a '98 car would be considered high, but that is what it said.

I did a search on auto trader, and the asking prices for a comparable model were not that low.

You're right; I will be watching; I wish I could be there to watch more closely, but they would probably not appreciate that! :P

My "other car"

100_05472.jpg

1968 Pontiac GTO, 400, 4 speed, 366 h.p., matching numbers car

*Get well soon, John Force!!!*

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Actually, this is the first time :o that we have actually flushed the system with another product. Before, we just drained it out, and filled with new product. I did not add the pellets then. We did not know about the bulletin or info. that suggested the frequent coolant changes, so this is probably our fault for poor maintenance. The owners manual that came with the car states to change the coolant at 150,000 miles. This is in the maintenance book that came with the car. We were never told anything different. I have talked to numerous guys this week concerning the frequent coolant changes and nobody has ever heard of it either; at least we are not by ourselves in this category!!! I have three friends with northstar engines in their cars; I asked them about their coolant; they have not done any changes either; I told them.............get ready............you're next!

The estimate for repairs that we were given Tuesday was $2800.00, plus the charge from the machine shop to inspect the heads. So, it is pretty close to what you all have suggested. The service manager said they have done the same work on several of the northstar engines; he said it was not unusual. I guess if we had taken it to the dealer for routine maintenance, we may have known about the recommended changes, but we are pretty much do-it-yourselfers; this time it didn't work!

PLEASE, Allow me to clarify the statement you made, it DOES state something different > "The owners manual that came with the car states to change the coolant at 150,000 miles. This is in the maintenance book that came with the car. We were never told anything different."

This is RIGHT out of your owner's manual from 1998, its 5 YEARS or 150,000 miles, whichever is OCCURS FIRST. Looks like you talked to the WRONG guys or didn't read the manual. Advise your friends who appear to not have read the manual before they have a problem! We have seen this before, many members think its 100,000 or 150,000 miles and they forget about the 5 YEAR limit....

post-2998-1181827916_thumb.jpg

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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The info. that I read was in the maintenance book; it is an insert that was inside the owners manual; and you're right; I haven't looked at it that much. I did read it when we first got the car; and have gone back and looked at it if we needed info. about something; I obviously didn't pay any attention to the coolant recommendations :(

My "other car"

100_05472.jpg

1968 Pontiac GTO, 400, 4 speed, 366 h.p., matching numbers car

*Get well soon, John Force!!!*

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O.K., just so you fellas won't feel too bad for me.......here is a picture of my "other car" that I am driving, while my STS is in the shop :lol:100_05472.jpg

My "other car"

100_05472.jpg

1968 Pontiac GTO, 400, 4 speed, 366 h.p., matching numbers car

*Get well soon, John Force!!!*

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And, on other days, I can drive this!!!

100_0549.jpg

My "other car"

100_05472.jpg

1968 Pontiac GTO, 400, 4 speed, 366 h.p., matching numbers car

*Get well soon, John Force!!!*

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The sad part is, we have taken better care of these the last few years than we have my Cadi!!! But, I guess that is a good thing!

My "other car"

100_05472.jpg

1968 Pontiac GTO, 400, 4 speed, 366 h.p., matching numbers car

*Get well soon, John Force!!!*

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That to me was the nicest GTO and the 66 is the second nicest. Love it....

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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