Hi, not been a while. I recently had the dreaded loss of power issue on an lseries engine. The pedal was hitting a power floor around 3500 rpm.

So I replaced air and fuel filter and intercooler hoses. Still the same. Then removed maf sensor and took it for a drive and viola. Issue now is the pcv valve I think (mushroom shape plastic on air intake before turbo) is coated in oil.

I want to figure out if this is normal before replacing the maf sensor. I hear the cheap ones are crap so I'm going for a Bosch one.


Any advice welcome thanks!

Stefan.

Issue now is the pcv valve I think (mushroom shape plastic on air intake before turbo) is coated in oil.

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i think you'll find that a crankcase vent system on any diesel or petrol engine
will be coated in oil .. ( or a mix of oil and unburnt fuel residue ) .. be the nature of it ..

problems arise when the valve ( and/or filter as on the td4 factory fit ) gets clogged up
with oil that's been cooked / oxidised .. i.e. sludge .. or in the case of the td4 filter thing
simply too much oil residue .. .. so it ends up not breathing .. crankcase pressure builds .. which ends up blowing turbo seals .. 'n other seals ..

i've no idea what the l-series system comprises of .. but if you can clean it out with white spirit .. do so .. ( i.e. if your worried about it's condition ) 'n make sure any incorporated 'valve' is working as it should ..
IF there's a cloth bog-roll type filter in there like the td4 .. change it ..