oldtruck lover

Changing the intake gasket again on my 66 330. Noticed oil pooling on the top side of the intake near several intake bolts. Removed the intake and found oil in several of the intake bolt holes in the head. Blew compressed air into the holes and found air easily escapes into the push rod passages on the holes with oil but not in the remaining holes. I'm guessing this is factory. I'm considering thread sealer to keep the oil from riding up the bolt to the top of the intake. Anyone else experienced this? Is thread sealer a reasonable solution?

oldcutlass

Thread sealer is the solution.

Run to Rund

If that is all that is wrong, you don't need to change the gasket. Just clean the threaded holes and bolts fairly well and goop on Permatex #2, the classic sealer. BTW, I have not heard of this source of oil leaking before on an Olds, so if you do remove the intake, investigate closely for any background issue.

joe_padavano

X2. This is a new one on me. It's possible your head was on the ragged edge of tolerance stackup or something. Those are not supposed to be through holes.

oldtruck lover

This car sat in a heated garage for 45 yrs after an accident and has 53K actual miles. Ran fine when started with no signs of a leak around the intake.. Removed intake to clean out sludge. Did not use RTV on intake gasket upon reinstall. Leaked coolant. Was told in a previous thread that I should have used RTV around the water passages. Removed intake again to install new gasket with RTV. Found oil on top of intake in spots where bolt holes are connected to push rod passages in the casting. These holes have bottoms and had oil in the bottom of the hole but compressed air easily escapes.. The passages must be near the bottom of the holes on the side of the hole. There are two on the right bank and two on the left. My theory is that engine vacuum drew oil up the bolt. I cant explain how it got on the top of the intake. Im going to try to thread a fine wire through the cavity to test my theory.

Run to Rund

Yes, you should use a thin amount of rtv on the water ports and replace the front and rear seals with beads of rtv. However, do not use rtv on the intake ports, use something like K&W copper coat. Gasoline eats rtv.