Oil in cylinders

Hello all,

Currently just rebuilt my motor (4.6 2v) due to a fuel wash issue. Had the heads rebuilt by a reputable builder near me (guides where fuel washed aswell). Got through dyno break in, however we were having a cam sensor fault so we were unable to continue onto tuning. Tuner got fuel trims set within 1%, timing is currently about 10 degrees.

Upon checking the cylinders we found oil, is it possible the rings are not broken in due to the low timing or not enough run time? or do I have a bigger issue going on? From what I've seen i don't think its normal to have oil in the combustion chamber on fresh builds. Catch can was empty, and can't see any smoking while running. I will attach a couple pics for reference, TIA.

Hi Justin

Do you have a documentation of the engine build?

How high is the piston to wall clearance?

the ring gap fits?

It looks like your problem is coming from the cylinder head.

Have the valve guides and stem seals been replaced?

Simon

PTW clearance was set to be around 1.5 to 2 thou using Line2line coating. rings gap was set 22 top and 24 bottom. both guides and seals where replaced, I did have a cam gear sensor fault that stopped from being able to finish the tuning process. I had been using a 99-08 cam gear which only had 1 lobe, whereas the 09-10 had 8 lobes on the cam gear.

Is it possible the cam sensor issue would lead to incorrect injector timing leading to fuel wash in the guides?

You say there is oil in the cylinder not gasoline, so I don't think it's the camshaft control, no matter how the camshafts are controlled, no oil gets into your cylinder via the camshafts and valves.

I think you have a mechanical problem

The cylinder head has no cracks? Did you check this during assembly?

Simon