Oil pooling in top of cylinder head.

[TonyMathis]

I have a 2007 CM870 that blew an injector tip. While diagnosing the problem I ran the engine with the valve cover off. In about a minute oil pooled up and spilled about a gallon over the rear of the head which explains the leak that 2 new gaskets have failed to stop. Surely those rubber valve cover gaskets are designed for splash sealing not immersion. The engine has less than 100k on an out of frame overhaul and this small leak at the rear of the valve cover is the only it has.

My question is are the head gaskets made with a restriction to slow drainage and if so can I enlarge the opening (in the gasket) without causing a lack of lubrication up top?

Also I checked the turbo and it had compressor wheel damage and pressure tested the cylinder with shop air and heard no valve leakage. The injector tip broke off while the engine was at idle building up air after sitting the weekend and only ran about 5 minutes until it was shut down by the driver. There was an intermittent knocking that went away after the driver heard what he described as a machine gun sound (turbo probably). During diagnoses no compression was visible in coolant tank.

I have 35 years experience with diesels but very little with the ISX so I don't know what to expect for cylinder damage from a tip. I'm going to scope it tomorrow but would welcome opinions from those with more ISX experience.