Fixing a long standing engine oil leak

[Pinder]

Since rebuild the engine back in 2016 I have been chasing a slight oil leak. After driving the car I would notice two small oil drops on the bell housing at the bottom of the engine. I was convinced this was a rear main seal leak and thought maybe during the rebuild I didn’t get it right .  This actual cause of this leak I finally figured out was a minor leak at the valve cover caused by the valve cover not being complete flat. It had a few low spots such that I could put feeler gauge in some areas while I had it on a flat granite countertop. I corrected this and re installed and so far so good , engine leak is gone.

See picture attached on how I flattened the valve cover.

[Pinder]

3 sheets of 120 grit sandpaper and move the cover back and forth until the bottom of the cover is shiny

[Kevkeller]

Good thinking. Thank you.

[Benz Dr.]

That doesn't always work. If the top of the cylinder head is warped, odds are the valve cover will warp with it. Changing to a perfectly flat valve cover may make it leak even worse.

I would check the top of the head to see if it's flat and determine from there. We had to fix the same issue recently and did that by cutting a long O-ring in half and placing it into the valve cover gasket at both ends so the gap would close up.

[Pinder]

That’s a really good point Dr Benz. I actually got the idea to do this from an old Post you wrote about keeping the heads Matched to the valve  covers. But when I did the rebuild I sent the head out to be machined . But not the valve cover.  It seems to have fixed the issue. See how it holds up in the hot weather and oil thinning but I am optimistic. I took the car out for a long drive on a wonderful day here in NJ.

I was thinking of using some type of sealant on the gasket but wanted to try this first.

Regards

Pinder.