Retorque aluminum cylinder heads on TPI?

[TedC]

On my stock 1989 with 56K, I noticed engine oil that appears to be coming between the block and heads. Not enough to be dripping down on the floor, but seems to travel towards the rear of the block on both sides and collects just over the starter and oil filter. Should aluminum heads after all these years be retorqued? If so, is this a major project, or just pulling the valve covers off? The manual shows 17 bolts, 8 which are exposed. I'm not sure if GM applied any sealant around the bolts/gasket that would twist and cause other issues forcing a complete gasket replacement. Before I do anything, I will clean up the block with simply green and verify the source. I purchased this vette late last year, and I don't either of the two prior owners every cleaned a single item in the engine bay area.

 

[tonylong]

BTT I wanna learn about this too. My 89 has 60K and a verry slight loss of oil. I learned way back that the Cyl head gasket can degrade and cause either oil or coolant leaks. The replacement gasket is better and shouldn't erode. I wouldn't mind retorqueing the heads, but replacing the gaskets may require machining the heads and/or block to be sure they are flat. just FYI.
Any comments appreciated for sure.

 

[Hrtbeat1]

Most likely its a small leak from the rear of the intake manifold. The L98 is notorious for this. The best fix is to take the complete intake manifold off, along the back edge of the block (horizontally) where the flat of the intake valley is, is the area you need to concentrate on. Take a punch and make numerous "dimples" in this area of the block. What you are trying to do is create more surface area. Now take some RTV gasket maker (The Right Stuff is the best I've found) and form a bead along the top edge of the block, and along the outer edge of the intake manifold. Let this firm up just a bit, then reassemble. Of course you need to clean all the oily residue up first or your bead of sealant will never stick.



G

 

[TedC]

Hrtbeat1, I'll clean up the bottom of the block this spring and verify the source, paying close attention to the rear of the intake manifold. According to the maintenance paperwork from the prior owner, when the dealership replaced the injectors a few years back, they also listed a new manifold intake gasket.