Hi All.

just recently i did engine service on my car and found oil in fuel filter housing, the amount is not great but filter was all black which indicates that engine oil getting mixed with fuel somehow ?

does anybody came across that before, is this major or common fault.

i did engine service before and usually fuel filter was clean but not this time.

any ideas?

its on superb mk2 2.0tdi 140

thanks

Are you sure the black isn't just crap from the fuel?

Fuel filters on diesels are often black in colour, if it isn't you are replacing it too soon

I have changed dozens over the years and it is not unusual to see them nearly black, although with modern fuel management and fuel sitting around for shorter periods at garages it is less common than it once was.

Modern diesel allows a lot of biodiesel in the blend. Biodiesel is great at clearing out the fuel lines, but the downside is that all that gunk has to go somewhere.

Diesel fuel filters will need changing a lot more often than ever before methinks. My previous diesel car needed a new filter in half the time/distance that VW recommended.

If it's got a problem it's the Tandem Pump leaking oil into the fuel, best way to decide is watch the engine oil level, if you are topping it up too often it will indicate a leak, if the oil is rising without you putting any in the leak is the other way around and the fuel is going into the sump, hth.

Tandem pump is the unit on the side of the head over the gearbox, looks kinda circular, if it is broken you won't see anything the damage is inside it.