Head Gaskets: DIY?
Thread Starter
Racer
Joined: Aug 2000
Posts: 460
Likes: 12
From: Gulf Shores AL
Head Gaskets: DIY?
Have a 91 with 180k miles on it. I'm getting some preliminary indications that
the head gasket may be failing (possible loss of coolant volume with no leaks). I'm looking for folks who have tackled the head gasket for opinions.
I have done a bunch of engine rebuilds on other cars, so I have a ton of general experience with this type of job, but I am wondering whether this is wise to do on the L98. I understand there are issues with aluminum parts etc. What are the gotchas on an L98? Is this job comparable to a head gasket job on other GM V-8s?
As a side discussion, does it make sense to pop the whole block out and redo the bottom end too? I've changed the oil religiously, and there is absolutely no evidence of oil consumption, so my guess is its solid. On the other hand, I anticipate driving the car a lot for several more years, so it may make sense to tear it down now. Has anyone torn down an apparently healthy block and found it to be a worthwhile exercise?
the head gasket may be failing (possible loss of coolant volume with no leaks). I'm looking for folks who have tackled the head gasket for opinions.
I have done a bunch of engine rebuilds on other cars, so I have a ton of general experience with this type of job, but I am wondering whether this is wise to do on the L98. I understand there are issues with aluminum parts etc. What are the gotchas on an L98? Is this job comparable to a head gasket job on other GM V-8s?
As a side discussion, does it make sense to pop the whole block out and redo the bottom end too? I've changed the oil religiously, and there is absolutely no evidence of oil consumption, so my guess is its solid. On the other hand, I anticipate driving the car a lot for several more years, so it may make sense to tear it down now. Has anyone torn down an apparently healthy block and found it to be a worthwhile exercise?
Le Mans Master
Joined: Feb 1999
Posts: 6,172
Likes: 11
From: somers, ny
Re: Head Gaskets: DIY? (jwg2)
if you have experience rebuilding engines, the L98 is no more difficult. If you're not burning oil and a compression and leak down test are good, i see no reason to rebuild the entire engine due to a head gasket failure.
Advanced
Joined: Jun 2001
Posts: 85
Likes: 0
From: Princeton NJ
Re: Head Gaskets: DIY? (jwg2)
I have not done it on an L98, but just did the head gasket replacement on my LT1 this summer (my manual had both the L98 and LT1 procedure, and it was pretty similar). I will say that the job was a BEAR. If I had to do it over again, I would have probably borrowed an engine lift, and taken the whole engine out to do the job, as there is very little room to do it in the engine bay (however, as I found out, it IS possible). The only big problem I ran into, was one of my EGR tubes being fused to my exhaust header. After realizing that the tube was not coming out, I cut it, bought a new tube, and got a set of SLP shorty headers (I probably could have salvaged the old header, but I used it as an excuse) ;). In the end, I didnt have any parts left over, and the car has been running great, so I think it was successful!
Advanced
Joined: Jun 2001
Posts: 85
Likes: 0
From: Princeton NJ
Re: Head Gaskets: DIY? (Mark92LT1)
BTW: if you do it yourself, its a great time to take those heads to a shop, and have them ported, and have a valve job done. The valve job is pretty inexpensive, and it is some nice insurance (have them check the springs, pushrods, etc, while they are at it.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Re: Head Gaskets: DIY? (jwg2)
I didn't find it difficult to do the heads and fortunately, GM used a redesigned head gasket on your model year which held down galvanic corrosion on the deck surface. You won't know the condition of the deck until you pull the heads, but if it's in bad shape you will need to pull the block and have the deck resurfaced.
Race Director
Joined: Aug 2000
Posts: 12,110
Likes: 50
From: SW Michigan
Re: Head Gaskets: DIY? (Mark92LT1)
I have had my 87's engine down to the block still in the car, changed every gasket on the engine... no problem even had the transmission out at the time so that might have mad it a little eaisier.......But I have done a head gasket change on the road, warped one of my aluminum heads had a spare set( had to make road trip with friend) We changed the heads on the car on the side of the road in the middle summer just outside of atlanta GA ( that was a warm one let me tell ya) If you have worked on chevy V-8's you can work on this engine just get a maunual and you'll be good to go. I used the cheap chiltons manualthe first time I sugest a good chevrolet manual.. have fun and as always with an engine rebuild dont forget the beer :cheers:
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Advanced
Joined: Oct 2001
Posts: 71
Likes: 0
From: Fairbanks AK
Re: Head Gaskets: DIY? (jwg2)
Before you pull the heads to replace gaskets, you need to find out if the gaskets are really where the problem lies. I highly doubt you have a head gasket failure if the car runs well, doesn't blow white smoke, or overheat. Your problem is most likely as simple as a blown radiator cap, as if it is the original one at 180K miles, it is most assuredly toast. Do a compression and leak down test, dye leak test, and pressure test the coolant system before even thinking about the head gaskets. Why waste your time and risk potential problems down the road, not to mention frustration, by digging into the engine when not necessary?
Intermediate
Joined: Jan 2001
Posts: 36
Likes: 0
From: Chesapeake VA
Re: Head Gaskets: DIY? (phrogs)
[QUOTE]A head swap on the side of the road...DANG!
All I can say to that is: GOD BLESS THE USMC !! :flag
Damn impressive. I've twice towed my '91 because of a bad alternator :nonod:
All I can say to that is: GOD BLESS THE USMC !! :flag
Damn impressive. I've twice towed my '91 because of a bad alternator :nonod:
Race Director
Joined: Aug 2000
Posts: 12,110
Likes: 50
From: SW Michigan
Re: Head Gaskets: DIY? (91BlkonBlk)
A head swap on the side of the road...DANG!
All I can say to that is: GOD BLESS THE USMC !! :flag
All I can say to that is: GOD BLESS THE USMC !! :flag
Drifting
Joined: Oct 2000
Posts: 1,257
Likes: 6
From: San Jose, CA, USA
Re: Head Gaskets: DIY? (Glock'94)
Hey - I've done worse, I towed mine about 2 miles home for what I thought was an alternator. But what turns out was an UNPLUGGED alternator....
Doh.
:conehead
Doh.
:conehead
