Here are two pics of the Mi16 cylinder head I recently dismantled. This car has done just 150 000Km. It looks like the oil had never been changed. It must have had at least one change, as it had an after market filter.
That black stuff is like tar and it crumbles easily. All the socket headed cap screws are full with the stuff.
It gets worse from there. This is an iron block engine. It has bad piston ridges in the bore. Quite incrediable considering the low mileage.
The oil filler pipe, approx. 38mm in diameter, was almost completely blocked. You can imagine what the sump looks like!
Amazingly, the crank is in reasonable condition.
This engine started easily and ran well.