Head Gasket Question
Thread Starter
Instructor
Joined: Jun 2008
Posts: 122
Likes: 1
From: Turnersville New Jersey
Head Gasket Question
1989 coupe L-98. I am in the process of changing the left head gasket.(Driver Side) When I pull the head, the gasket was broken at the number 7 cylinder. This confirmed my problem. In the process of removing this head I broke off the three exhaust bolts that were rusted really bad.
My question is should I replace the right side head gasket as well. There is no sign of failure and the plugs and compression are fine. I was wondering if I can leave it alone since I don't want to mess with that other exhaust manifold and all that additional work.
Any information would be appreciated.
Thanks!!!!
My question is should I replace the right side head gasket as well. There is no sign of failure and the plugs and compression are fine. I was wondering if I can leave it alone since I don't want to mess with that other exhaust manifold and all that additional work.
Any information would be appreciated.
Thanks!!!!
Corvette Enthusiast
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From: So. Cal.
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How many miles on engine? If its got over a 100,000 miles I would probably do both. You already have all the intake stuff off. Good Luck
L98's are known for blown head gaskets.
L98's are known for blown head gaskets.
Safety Car
Joined: Jul 2008
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From: Made In America
St. Jude Donor '10-'11
Head gasket experience here. Replace both of them. It will bite you in the @$$ and when you least expect it! Once you get that high, it's just a ticking time bomb. Like said, you already got most of it off, replace it all and be done with it for another 100,xxx miles. It's a real task to get them replaced.
It's a real task to get them replaced.
Pro
Joined: Jan 2004
Posts: 565
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From: Toronto ON
original specs
Could you explain this, please?
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Especially the 1989's. Couldn't remember the reason why they let go with such regularity in that model year.
Safety Car
Joined: Jan 2004
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Why did you suspect a head gasket failure, and what tests did you run? I was told to pull one spark plug at a time and start the engine. Then look in the spark plug hole to see if coolant comes out. Changing the head gaskets look like a pain for someone with no experiance and no proper tools.
I have an 89, and my compression checked out to spec. I have noticed some oil in the coolant, but no coolant in the oil.
From Left to Right: 1234
From Left to Right: 5678
I have an 89, and my compression checked out to spec. I have noticed some oil in the coolant, but no coolant in the oil.
From Left to Right: 1234
From Left to Right: 5678
Thread Starter
Instructor
Joined: Jun 2008
Posts: 122
Likes: 1
From: Turnersville New Jersey
There was a cloud of white steam comming out my exhaust. When I pulled the plugs number #7 was soaked with coolant. The other plugs were fine. Also I will used the Fel-Pro Gaskets. Thanks for the tip.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
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From: San Diego, Ca
See my response to your Fan Post: http://forums.corvetteforum.com/c4-g...-question.html
Typical failure for the reasons GM gave us back in '90, though I'd guess yours may have blown before (given the mileage).
Typical failure for the reasons GM gave us back in '90, though I'd guess yours may have blown before (given the mileage).
Team Owner
Joined: Mar 2001
Posts: 54,124
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From: Cincinnati, Oh USA
OEM is bore: 4.130" and compressed thickness: .055". Does the replacement have to be the same spec? Having a hard time sorting this out... Can I use the Felpro HS7733PT9 gasket set? Rock Auto says something about this set (containing head gaskets) is "used for upper engine repair only, typically on a valve grind."
Could you explain this, please?
Could you explain this, please?
Safety Car
Joined: Jan 2004
Posts: 3,759
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See my response to your Fan Post: http://forums.corvetteforum.com/c4-g...-question.html
Typical failure for the reasons GM gave us back in '90, though I'd guess yours may have blown before (given the mileage).
Typical failure for the reasons GM gave us back in '90, though I'd guess yours may have blown before (given the mileage).
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Nope - There were 5 or so lawsuits over the issue posted at NHTSA.gov back in 2000. That's an amazing number, given the state of the internet at the time, and these postings covered claims dating to the early '90's. GM's Bulletin was issued in November '90 yet the redesign was only installed on the '91, though the Bulletin addresses any vehicle using the 113 Heads. Certain language referencing galvanic corrosion has now been edited out.
There were plenty of owners with the same issue when I joined the Forum. Many reported that they found evidence that the gasket had been leaking for some time before discovering the problem. Mine probably started leaking at 25,000 miles or less and finally let loose at around 50,000 miles. My theory is that it always occurs at the rear of the heads due to the coolant restrictors in the intake gaskets. That allows more coolant to sit around there longer and once electrolysis takes over, it eats away the head gasket (in amazingly short time). To prevent it from happening, you need to make sure that no dissimilar metals come in contact with whatever coolant you're using so be sure to use pipe thread sealant on any sensors (CTS, Aux Fan Switch etc) and the thermostat bolts.
There were plenty of owners with the same issue when I joined the Forum. Many reported that they found evidence that the gasket had been leaking for some time before discovering the problem. Mine probably started leaking at 25,000 miles or less and finally let loose at around 50,000 miles. My theory is that it always occurs at the rear of the heads due to the coolant restrictors in the intake gaskets. That allows more coolant to sit around there longer and once electrolysis takes over, it eats away the head gasket (in amazingly short time). To prevent it from happening, you need to make sure that no dissimilar metals come in contact with whatever coolant you're using so be sure to use pipe thread sealant on any sensors (CTS, Aux Fan Switch etc) and the thermostat bolts.
Safety Car
Joined: Jan 2004
Posts: 3,759
Likes: 8
Nope - There were 5 or so lawsuits over the issue posted at NHTSA.gov back in 2000. That's an amazing number, given the state of the internet at the time, and these postings covered claims dating to the early '90's. GM's Bulletin was issued in November '90 yet the redesign was only installed on the '91, though the Bulletin addresses any vehicle using the 113 Heads. Certain language referencing galvanic corrosion has now been edited out.
There were plenty of owners with the same issue when I joined the Forum. Many reported that they found evidence that the gasket had been leaking for some time before discovering the problem. Mine probably started leaking at 25,000 miles or less and finally let loose at around 50,000 miles. My theory is that it always occurs at the rear of the heads due to the coolant restrictors in the intake gaskets. That allows more coolant to sit around there longer and once electrolysis takes over, it eats away the head gasket (in amazingly short time). To prevent it from happening, you need to make sure that no dissimilar metals come in contact with whatever coolant you're using so be sure to use pipe thread sealant on any sensors (CTS, Aux Fan Switch etc) and the thermostat bolts.
There were plenty of owners with the same issue when I joined the Forum. Many reported that they found evidence that the gasket had been leaking for some time before discovering the problem. Mine probably started leaking at 25,000 miles or less and finally let loose at around 50,000 miles. My theory is that it always occurs at the rear of the heads due to the coolant restrictors in the intake gaskets. That allows more coolant to sit around there longer and once electrolysis takes over, it eats away the head gasket (in amazingly short time). To prevent it from happening, you need to make sure that no dissimilar metals come in contact with whatever coolant you're using so be sure to use pipe thread sealant on any sensors (CTS, Aux Fan Switch etc) and the thermostat bolts.
My 89 has 90K miles on it. I have no apparant coolant in the oil. It doesn't overheat. Looking at the pics of my spark plugs above, do any of them look like a coolant leak? I know they all look like they are carbon fouled. So, I would assume if one was leaking, I should have one or two spark plugs that are clean.
My compression test was good. Though, there is alot of crud I noticed in the radiator fines. Does this look like Galvanic corrosion, or maybe just those sealer pellets from the dealer?
The only other thing, is it seems the coolant system holds pressure real good. The other day I hadn't driven it for a couple of weeks, and with the engine still off, I pulled the radiator cap lever to remove the cap, and got a couple of burps in the overflow tank.
Though, when I tried to do the combustion leak tester, I wasn't able to because coolant kept squirting out the radiator opening. I removed a third of the coolant on the cold engine, started it and let it get up to temp. Then I noticed coolant was gushing out. I'm guessing that doesn't sound good?
Last edited by samsonb; Mar 27, 2009 at 05:39 AM.
