Sooty Intake Manifold on M35B

[KeelsonGraham]

Recently, after taking off the air filter to clean it, I ran my finger around the inside of the manifold and picked up a very thin film of oily soot. I'm experienced with auto petrol engines - not with diesels, but I assume this is abnormal?

The engine starts immediately first time, every time and runs sweetly (albeit a little hot) so I'm reluctant to fix it if it ain't broke.

I assume this could be due to back flow from one or more inlet valves, either because the tappet clearance is too small or because a valve isn't seating correctly?.

Has anyone else seen this?

[KWKloeber]

When The B engines go out the factory door they have the crankcase breather hose run to the air intake.  Does yours?

[KeelsonGraham]

i'll check!

[Ron Hill]

Keel : I don't believe that you have a problem.  As Ken said the newer Universal M35B and XM25 XPB engines all have their oil pan breather vented in to the intake manifold.

A thought

[KeelsonGraham]

Thank you Ron. The oil breather would certainly explain it.