The cylinder wall is formed by a Silitec liner: an aluminium-silicon alloy which the maker cast into the aluminium cylinder in order to reduce friction, heat and wear. This material, however, could not cope with the high temperature and the occasional detonation of this engine.

On a damaged liner the cylinder wall becomes scored, and from then on the piston ring no longer seals: oil consumption rises and compression falls. The same material also wore the valve guides seriously. The maker finally switched to the Nanoslide coating, precisely because of Silitec's cylinder scoring problems.

It is not the mileage that marks out the affected cars but the engine number. Into engines above 2789xx 30 266191 the maker already fitted cast-in iron liners, which means that from there on this failure mode does not exist. It is reported on examples with an engine number below that, typically above 120 000 kilometres.

The symptom is blue smoke, rising oil consumption and uneven running. The repair is machining or replacing the block, which makes this the most expensive failure on this engine.