Oil leaking from cap. I'm stumped :(

[Balleristic31]

Alright so here's the situation: there is a good amount of oil leaking from the fill cap on my m42. Here is what I've tried to do to fix it and none have been successful.

New oil cap (cheap amazon one)

Cleaned all of the wrinkle black paint off the caps sealing surface. (No change)

Then I figured my little valve cover breather filter was clogged and it was causing excess crank case pressure pushing the oil out of the cap. Took the filter off to run just the hose, and once again oil still leaks out.

I'm also not overfull oil level wise.

I'm stumped. Anyone have by ideas why this still occurring? Maybe the amazon cap is bad? I need ideas

[ak-]

Your breather isn't plumbed back to your intake?
Put it back for dem vacuumz.

With the crank case hose cleared, I'd figure you just have a poopy cap.

[Exodus_2pt0]

Ideally, you want your crankcase to be under a vacuum at idle. Reason is not only just to keep pressure down, but to stuck out any fuel vapor and prevent oil dilution. Most engines can get away with a breather, but having the vacuum hose connected is better.

If your boosted, be sure to have a one way check valve in there to prevent your intake charge from pressurizing the case.

[roguetoaster]

Take the gasket off of the new cap and put it on the old perhaps? Worked for me

Failing that try bending the metal retaining arms (on either old or new, so long as the new gasket is there) so you achieve a slightly better seal.

[Balleristic31]

Will try all of the above thanks!

[Balleristic31]

So I bought a new oe cap from BMA and the leaking stopped. Lol

Moral of the story, don't buy amazon oil caps! They suck!

[E30_fiend]

lol Nick. For future reference, I have had good luck with flipping the gasket over and reinstalling it. The gasket install progress at any factory is done by a human so there is always room for operator error. You may have just gotten a cap that had the gasket flipped the wrong way.

Glad you got it solved though.

[Exodus_2pt0]

So I bought a new oe cap from BMA and the leaking stopped. Lol

Moral of the story, don't buy amazon car parts! They suck!

Fixed.

I found a set of M20 exhaust gaskets on amazon for half what they sold anywhere else.

I thought to myself, sweet! And clicked the purchase button, only to receive 1 gasket a week later. I guess if you aren't a car guy, the thought process is "half an exhaust gasket kit, half price!". If only you could purchase them individually.

I still have that gasket.