OM617 manifold oil = broken valve guide

[Stretch]

Dear All,

I've been enjoying my self recently pulling my car to pieces and I've found the following (potentially) alarming amount of oil on the inlet manifold - well most of it seems to be coming from the inlet side.

I'm quite new to Diesels so I don't really know how to gauge this problem. Is it a sign of impending doom? Or should I just clean it up and carry on as usual?

The car in question is a 1981 W123 300D. It has just done 100k miles / 160k km (Probably true - well more or less - I've got a pretty complete service history). It is a European model - no turbo - no EGR thingy.



Note the pooled oil in the throats.



Exhaust manifold



Pooled oil in the inlet manifold



The underside of the inlet manifold



Oil sitting on the gasket

I know I'm now driving an oil burner but isn't this excessive?

Fuel consumption:- I regularly get about 10km to the litre despite a heavy right foot.

Engine oil consumption is not at all noticeable.

Any help / advice / theory on where this oil is coming from will be greatly appreciated.

(Worn rings / valve seals - next step compression test?)