Frustrating oil leak!!!

[Red68]

I recently rebuilt my 327 small block and I have an oil leak. It is coming from the back drivers side of the engine. I removed the new valve cover and noticed a little oil under the gasket so I applied some gasket sealer and thought I fixed it, apparently not. I can see it drip/run somewhere from the distributor to the edge of the block where the head sits, just above the oil filter. I have checked the seal between the intake and the block and applied some sealant with my finger, I cannot feel any fresh oil in the intake area.

I have used a small mirror to look on the back side of my engine and cannot see where it may be coming from.

could it be a crack in the block somewhere that would allow it to leak?

Anyone have a similar problem that may have a solution?

Thanks

[ujsf01]

Hey Red,
Oil leaks can be very frustrating when they are like this. One thing you might try is clean the area off thoroughly with brake cleaner, make sure it is good and dry, then prior to starting the engine, spray some foot powder in the area where you are seeing oil. When the leak starts, it will leave a trail to the source in the powder. If you have an inspection mirror that you can look in that area while you are waiting for the leak to show, that would be great. Once you repair it, the powder comes off with water. I would almost suspect either the distributor gasket or if the fitting on the back of the block where the oil pressure sender is usually placed. I almost always have to seal that fitting with teflon tape, even though it's a pipe thread.
Hope this helps!

[Autoblueprint]

Originally Posted by ujsf01

I would almost suspect either the distributor gasket or if the fitting on the back of the block where the oil pressure sender is usually placed. I almost always have to seal that fitting with teflon tape, even though it's a pipe thread.
Hope this helps!

I agree.

[cdowns]

do you have a proper PCV system? lack on that can build pressure in engine and oil leaks result

[Red68]

Thanks Steve, I will try the foot powder idea. I will double check the dist. gasket, I dont see any oil leaking around it last i checked. I checked the fitting for the oil pressure line connects, replaced it with a new fitting and teflon tape, dont see anything coming from this area.

Cdowns- When I reinstalled my engine I put a new PCV valve on the drivers side valve cover which connects to my carb and I have a vent on the opposite valve cover. Is this correct setup?

Thanks guys

[sameyrasmea72]

I had a oil leak that drove me crazy. I looked for it and had 3 other people look for it. I finally took it to the guy who built the engine and he could not find it so he completely power washed it and still could not find it so he took it out on the highway. Turns out it was the back of the intake gasket and it only leaked when under high RPM"S...... Just a thought........Jason

[rsavage]

It has been my experience, for whatever that is worth, that oil leaks on a newly put together engine are often from the rear intake manifold gasket.

[ubtripn]

I had one coming from my oil sending unit behind the distributor on my 350.

[ujsf01]

If it does end up being the seal on the back of the intake that goes across the rail on the block, I have found that the GM sealer that we use in repair on Duramax diesels works better than any other RTV I have seen. Of course, you just substitute it for the rubber end seal and unless you're just an absolute purist to the core, no one will ever know. Just make sure you use about a 1/4 bead all the way across and up on the gasket on each side just a hair.

[lil hoodlum]

Since you say it is a new valve cover, I would check that first. Maybe swap the left valve cover for the right side one and see if the oil leak follows.

It's possible the new valve cover isn't sitting completely flush with the cylinder head.

Keith

[Hottrucks]

I got a nickle that says you have a screw on filter leak...I chased the same one its the gasket thats between the screw on filter adapter and the block not the filter but above that...take the filter off and look up there will be a couple 7/16" ( maybe 3/8) bolts) on each side of the threaded area the filter screws on...take them out drop out the disc and above it is an "O" ring that dries out and cracks....you can get one from a equipment shop

.

[Red68]

Originally Posted by Hottrucks

I got a nickle that says you have a screw on filter leak...I chased the same one its the gasket thats between the screw on filter adapter and the block not the filter but above that...take the filter off and look up there will be a couple 7/16" ( maybe 3/8) bolts) on each side of the threaded area the filter screws on...take them out drop out the disc and above it is an "O" ring that dries out and cracks....you can get one from a equipment shop

.

That could be, I don't recall installing an "O" ring when I reassembled the engine. I will check that out.
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[Hottrucks]

when I say "O" ring its one of the square "O" rings...I had a hell of a time trying to find one till my buddy checked his O ring set from Catapillar engines it was a perfect fit....

Chances are you engine was set up for a canister filter and its the adapter for screw on filters thats leaking..people forget about this all the time..me included????

[Red68]

I found a gasket set on jegs website do they sell the right one?
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