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Thinking Head Gasket?


jldro

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Ok, after reading hundreds of post in this forum, I think I have a bad head gasket or two on a 97 Seville STS.

Brief History: I bought this car from an older gentlemen about 2 months ago. He had kept up on standard maintenance with the help of a local garage. What I can tell basic oil changes, tire, etc. I doubt he ever replaced the antifreeze. I know that he had mentioned that he had an issue with the cooling fans not turning on and overheated a few times. The local garage fixed the fan problem and replaced the thermostat at his request. That took care of the overheating problem.

Symptoms: Ok I purchased the car with 124000 miles (of course before I read about the problems). Just to be safe I thought I would do a tune up on the engine, I replace plugs, wires, pcv valve, and belt. Plugs were a little white (assume burning lean) but not to much to be to concerned. After a couple of weeks of driving the car (average 500 miles per week) I received the check coolant message, so I filled it up with Dex Cool 50/50. The following week I received the light again and filled again. I am using about 3/4 of a gallon to 1 gallon a week. I have no visible leaks, but can smell antifreeze in the driver side engine compartment. I also noticed I was getting a little more condensation out of the exhaust in the morning, not to uncommon it 20 degrees outside. Well longer story shorter, I know have a fog machine when I start the vehicle whether it sits over night or for 5 minutes. I can defiantly smell antifreeze in the exhaust cloud that follows me. There is no oil discoloration or reason to think it is getting into the block. The engine will miss a little in the morning on a cold start but levels out with in a minute. Although every symptom says head gasket, I am unsure, I think the car runs to good with great pickup to be a head gasket, but can not think of anything else it could be. Please let me know what you think.

I can't wait to pull this engine!

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any caddy owner who has an overheating and coolant loss issue and than sells the car with a promise it is ok is suspect. IMHO, the seller should sell it as "condition unknown", buyer beware. you can get a test kit for the coolant to verify but it sounds like HG time. i used the timesert kit and than sold it so my total cost was reasonable. are you going to do the work? now i would lean towards studs but that is $500+ for just the studs plus any other new parts you put on the motor. the blocks seem fairly stable. cylinder liner cracks or porous blocks are rare but do occur. you should not have to touch the bottom end but think about sealing any case oil leaks if you have them.

Edited by joeb
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I thought it was possible that I had a bad head gasket, and I am going to give you a few things I was told to look for.

-Start your car with the coolant cap off (and the car cold) and look in the coolant tank for bubbles or "false boiling". This would be caused by exhaust gases in the coolant system.

-Check your oil. Do a change if necessary. Coolant in the oil will make it look milky or foamy...kinda like a milkshake

-Sweet coolant smell from exhaust (you said you have this)

-Have your coolant tested for combustion gases

-Do a coolant system pressure test: With the spark plugs removed from the engine, the coolant should be pumped up to 15psi with a cooling system pressure tester pump for several hours. The pressure should be maintained even if it is dropping. After several hours, the engine should be rotated with the starter. If coolant spews out of any the spark plug holes, the headgasket has failed.

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I thought it was possible that I had a bad head gasket, and I am going to give you a few things I was told to look for.

-Start your car with the coolant cap off (and the car cold) and look in the coolant tank for bubbles or "false boiling". This would be caused by exhaust gases in the coolant system.

-Check your oil. Do a change if necessary. Coolant in the oil will make it look milky or foamy...kinda like a milkshake

-Sweet coolant smell from exhaust (you said you have this)

-Have your coolant tested for combustion gases

-Do a coolant system pressure test: With the spark plugs removed from the engine, the coolant should be pumped up to 15psi with a cooling system pressure tester pump for several hours. The pressure should be maintained even if it is dropping. After several hours, the engine should be rotated with the starter. If coolant spews out of any the spark plug holes, the headgasket has failed.

Thank you for your reply.

My oil is ok. I will get the combustion gas kit before I attemp any head gasket repair, unfortunatly I live in the middle of no where and the closest autoparts store 25 miles away and my only vehicle looks like a fog machine I am scared to drive it. I did not think about doing a pressure test on the coolant system and I might even have an old tester laying around. I will try and find it and do that first.

Again Thank you for the reply.

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any caddy owner who has an overheating and coolant loss issue and than sells the car with a promise it is ok is suspect. IMHO, the seller should sell it as "condition unknown", buyer beware. you can get a test kit for the coolant to verify but it sounds like HG time. i used the timesert kit and than sold it so my total cost was reasonable. are you going to do the work? now i would lean towards studs but that is $500+ for just the studs plus any other new parts you put on the motor. the blocks seem fairly stable. cylinder liner cracks or porous blocks are rare but do occur. you should not have to touch the bottom end but think about sealing any case oil leaks if you have them.

I have looked around the forum and I think I agree that I will spend the extra money for the studs, if and when I replace the head gaskets. I believe the rest of the engine is ok, but then again I did not think the head gasket was bad when I bought the car, Maybe a little more looking should be done first.

Thanks

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I thought it was possible that I had a bad head gasket, and I am going to give you a few things I was told to look for.

-Start your car with the coolant cap off (and the car cold) and look in the coolant tank for bubbles or "false boiling". This would be caused by exhaust gases in the coolant system.

-Check your oil. Do a change if necessary. Coolant in the oil will make it look milky or foamy...kinda like a milkshake

-Sweet coolant smell from exhaust (you said you have this)

-Have your coolant tested for combustion gases

-Do a coolant system pressure test: With the spark plugs removed from the engine, the coolant should be pumped up to 15psi with a cooling system pressure tester pump for several hours. The pressure should be maintained even if it is dropping. After several hours, the engine should be rotated with the starter. If coolant spews out of any the spark plug holes, the headgasket has failed.

Thank you for your reply.

My oil is ok. I will get the combustion gas kit before I attemp any head gasket repair, unfortunatly I live in the middle of no where and the closest autoparts store 25 miles away and my only vehicle looks like a fog machine I am scared to drive it. I did not think about doing a pressure test on the coolant system and I might even have an old tester laying around. I will try and find it and do that first.

Again Thank you for the reply.

If you firmly believe the head gasket is gone, then you might want to try getting another ride to the auto parts store. It would probably do more harm than good to keep driving it in the condition it's in, especially if you are having overheating issues. Overheating causes head warping (especially on aluminum heads), and there's nothing you can do to fix that besides replacing the heads. Just a thought.

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Ok here is the update. I guess living in the middle of no where doesn't help working on cars. I got a ride to town, there are three auto parts store (Auto Zone, Napa, and Car Quest) and none of the carry what they call block tester fluid, I guess that is the same thing, they said that you put it in the radiator and it will change colors if it is getting any combustible gas into it. So I order it. It will be a few days until I can get it in the car to be sure. One thing I did was open the radiator cap and ran the car for about 20 minutes, I did not see any bubbling in the antifreeze, although it still smokes like hell. Just to clarify, I am not having any problems with the car over heating, the over heating problem was with the previous owner, and was fixed. The car did not smoke at all when I bought it but has got progressively worse over the last month. The car is currently parked and will not be driven until I am sure what is wrong. I am guessing it is the head or head gasket because I do not know of another way that anti freeze could get into the exhaust. I am looking for someone to help me confirm that this is the case, before I drop the engine and spend almost $1000.00 on the car. My luck GM would hide some stupid little vacuum hose somewhere and I would find it after I replaced the head gaskets and pulled bolts. I will keep you up to date with what I find. Also, since I am pretty sure I will be changing head gaskets I will take as many pictures as possible to post for the next person that get the lucky engine pull.

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Your symptoms sound like head gasket breach

miss in the morning for 5 minutes

coolant smell out of exhaust

steam at exhaust

Put your nose into the coolant tank and take a smell, you may smell exhaust fumes and you can save the cost of the tester

Compare the timeserts and the studs before you do the job

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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Your symptoms sound like head gasket breach

miss in the morning for 5 minutes

coolant smell out of exhaust

steam at exhaust

Put your nose into the coolant tank and take a smell, you may smell exhaust fumes and you can save the cost of the tester

Compare the timeserts and the studs before you do the job

Thanks for the advice.

Definitely exhaust in the antifreeze. Guess I am canceling the tester. Any preference to the timeserts or studs. Timeserts are definitely a little cheaper, just want to make sure I don't have to do this twice.

Thanks again.

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I guess i am the proud new owner of head gasket change. I have read several post in the forum and feel confident, that although it will be a pain, it is possible to change the mysterious head gasket on the northstar. I would like to thank everyone on this site, everyone has been very helpful and I will try to reciprocate where possible. This is my first Cadillac and with in a month of owning it I have meet all you great people and will be around for awhile. Love my car, just didn't think I would be into such a project so quick. I guess it's love.

Thanks again.

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The symptoms you have are different than the symptoms that Carla was showing. The coolant smell is probably a leak at the crossover seals or water pump body seal, but you have additional symptoms that indicate likely head gasket.

I have the miss in the morning, exhaust smell in the coolant and coolant smell at the exhaust plus it runs much hotter than in the past and will spike in temp if I get in traffic

I was very optimistic about the studs but I understand that there have been some problems with them pulling also, I plan to do a little more research before I do my job

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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I guess i am the proud new owner of head gasket change. I have read several post in the forum and feel confident, that although it will be a pain, it is possible to change the mysterious head gasket on the northstar. I would like to thank everyone on this site, everyone has been very helpful and I will try to reciprocate where possible. This is my first Cadillac and with in a month of owning it I have meet all you great people and will be around for awhile. Love my car, just didn't think I would be into such a project so quick. I guess it's love.

Thanks again.

How much did you pay for this car?, if you dont mind

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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I guess i am the proud new owner of head gasket change. I have read several post in the forum and feel confident, that although it will be a pain, it is possible to change the mysterious head gasket on the northstar. I would like to thank everyone on this site, everyone has been very helpful and I will try to reciprocate where possible. This is my first Cadillac and with in a month of owning it I have meet all you great people and will be around for awhile. Love my car, just didn't think I would be into such a project so quick. I guess it's love.

Thanks again.

How much did you pay for this car?, if you dont mind

$2000.00, but besides the great white cloud of smoke that follows me, the car runs great, the body looks like it came off the showroom floor, and the interior is in very good shape, it is fairly loaded and everything but the cd player works. The car looks to be very well kept. I figure if I have to dump another $1000.00 into it, it will be worth it.

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I guess i am the proud new owner of head gasket change. I have read several post in the forum and feel confident, that although it will be a pain, it is possible to change the mysterious head gasket on the northstar. I would like to thank everyone on this site, everyone has been very helpful and I will try to reciprocate where possible. This is my first Cadillac and with in a month of owning it I have meet all you great people and will be around for awhile. Love my car, just didn't think I would be into such a project so quick. I guess it's love.

Thanks again.

How much did you pay for this car?, if you dont mind

$2000.00, but besides the great white cloud of smoke that follows me, the car runs great, the body looks like it came off the showroom floor, and the interior is in very good shape, it is fairly loaded and everything but the cd player works. The car looks to be very well kept. I figure if I have to dump another $1000.00 into it, it will be worth it.

you should post a picture. I'm sure I'm not the only one who would like to see it.

big4870885.jpg

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I guess i am the proud new owner of head gasket change. I have read several post in the forum and feel confident, that although it will be a pain, it is possible to change the mysterious head gasket on the northstar. I would like to thank everyone on this site, everyone has been very helpful and I will try to reciprocate where possible. This is my first Cadillac and with in a month of owning it I have meet all you great people and will be around for awhile. Love my car, just didn't think I would be into such a project so quick. I guess it's love.

Thanks again.

How much did you pay for this car?, if you dont mind

$2000.00, but besides the great white cloud of smoke that follows me, the car runs great, the body looks like it came off the showroom floor, and the interior is in very good shape, it is fairly loaded and everything but the cd player works. The car looks to be very well kept. I figure if I have to dump another $1000.00 into it, it will be worth it.

you should post a picture. I'm sure I'm not the only one who would like to see it.

I will get a decent picture when I get it in the garage and get the 8 inches of snow off it.

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Hahaha, I hear ya. Mine's sitting in the driveway covered in snow right now, and it only snowed last night and a little this morning. I hate winter. Road salt is so bad for a nice car.

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Hahaha, I hear ya. Mine's sitting in the driveway covered in snow right now, and it only snowed last night and a little this morning. I hate winter. Road salt is so bad for a nice car.

Winter is the only time my cars break down. They will drive fine all sumer when its nice to work on them and then blow a head gasket in the winter. I think I am going to blow my head gasket, LOL

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I was gonna say sure sounds like HG to me, but you seem to have confirmed it.

As for Timeserts or studs. Studs seem to be the way to go. If not then I'd use Norms serts over Timeserts.

http://www.northstarperformance .com

Carla, don't count on coolant in the oil as a symptom. Northstars rarely do it.

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I was gonna say sure sounds like HG to me, but you seem to have confirmed it.

As for Timeserts or studs. Studs seem to be the way to go. If not then I'd use Norms serts over Timeserts.

http://www.northstarperformance .com

Carla, don't count on coolant in the oil as a symptom. Northstars rarely do it.

I'm aware of that, I just forgot to note it. I read that when I was looking for info on mine a few days ago actually. I was just listing general things to look for, as rarely doesn't mean never. Good catch though. I wonder why though? Maybe due to such high compression in the cylinders making it harder for coolant to get in there, but easier for combustion gases to get into the coolant? Just a thought....

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what state do you live in? cold makes an already tough job just that much more miserable. i did my headgaskets in july-august. you have a cherry picker? and engine stand? and shop manual? somewhat tricky job for a caddy novice. i remember drilling and tapping the headbolt holes and wondered if it was going to work.

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Can anyone tell me the difference between studs and timeserts? And what would a Cadillac - Dealer use if they repair the head gaskets? My head gaskets have been replaced some months ago with original gm parts, I only know how it's called in german... they used "Dehnschrauben" The only translation for the german word I can find would be "extension bolt", would you call a stud or a timesert an extension bolt??

If you do the head gasket job I would think of changing anything that is better (or only) accessable with the enging off the car. The upper oil-pan seal is now leaking a little bit on my car and the mechanican told me that he would have to remove the engine to change it. :(

My Northstar had no oil in the coolant when the head gaskets were faulty and it was good to drive as well. I drove the car until the message "overheating enging, switch off" came up on the dic. I know many cars where driving with an overheated engine would probably cause a crack in the cylinder head. I was told because the Norhstar is an all aluminium engine it can tolerate a little bit more, but however be aware of driving under this conditons.

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Pretty sure "extension bolt" would fall under stud, as that is pretty much what a stud is. A timesert on the other hand is a steel, threaded insert that gets put into the block (after drilling and tapping out the original hole to make it bigger) where the original bolts came out, then new bolts are put into the timeserts.

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