VW (pumpe duse) TDI engine cam wear - valve or injector lobes ?

[Tmoose]

This link explains that in the pumpe duse system the rocker actuated injectors also jack the fuel pressure way up, but postulates that since the valve lobes were narrowed to make room for the injector lobes, the narrowing of the cam lobes is what causes cam and lifter failure. That Sounds logical, if it really is valve lobes that fail.

http://www.myturbodiesel.com/wiki/vw-and-audi-tdi-fuel-injection-systems-1996-present/

 

[BrianPetersen]

Former owner of one of those engines here. I sold mine with 430,000 km on it, all of that with the original factory recommendation of 5w40 synthetic oil (not the later 5w30 that VW claims is backward compatible), and had not a lick of trouble with it.

If the problem happens, it is most certainly the valve lobes that fail, not the injector rocker lobes - and at that, generally the exhaust valve lobes.

 

[tdirs1]

Ive changed lots of pd cams for this wear and i got told its fuel that is forced past the injector seals and sprays onto cam lobes.

 

[BrianPetersen]

^ Only if someone improperly installed the injectors. I never had any issues with fuel dilution on mine.

Unsuitable engine oil, on the other hand, will wreck the camshafts and lifters every time.