Quote Originally Posted by t j View Post
I had that happen from a blown exhaust gasket. One of the gaskets inside the fan cowling.

503's seem to have a lot of oil in the exhaust and the fan blows it through the fins on the heads.

I had taken the exhaust Y off to check the rings on the exhaust side and only replaced the 2 outside gaskets between the fan cowl and the exhaust Y.

I thought I would get away with not replacing the 2 inside gaskets between the cylinders and the fan cowling being that I didn't take the cowling off but no.
We did that inspection last annual, pretty sure we used new gaskets. Of course this shot is from the intake side rather than exhaust, but I suppose with fan air the oil can be migrating over there. Tom, tell me again just to confirm, the oil you sourced from the exhaust made it over to the intake side of the heads?

If I can rule out cracked heads, I can relax.

Thanks.