slight leak

[Glenn Mills]

I have some oil residue a few drips down the rear of the block on my 1990 5.7. took off the insp cover it does not seem to be coming from the rear seal. Cleaned it off just cant pinpoint where its starting rear intake maybe distributor. Any common problems I should know

Glenn Mills
Moose

 

[G Winter]

Valley gasket leaking on a chevy smallblock happens a lot.I have a 90 , at about 76k I had a problem with oil on the bellhousing and trans. I traced it to the valley gaskets. I found that the front was also leaking a little so I replaced the intake gasket.
From the factory they use a silicone for the valleys and it dries out after a few yrs. Even if the new gasket comes with a valley gasket don't use it. Use a good quality silicone sealer.
Be sure to clean the surface of any oil or it will not seal. I find that brake cleaner as the last step works very well.
Replacing intake gasket takes some time as the plentum and runners have to come off.The biggest pain was cleaning the old gaskets off the runner ports. A little tip, make use of a digital camera at each stage of dissasembly. Everything has to come off in an order and the same going together.

Glenn


PS Wellcome to the CAC, you will find many friendly and helpfull people here.