TD4 diesel in oil

Am I right in thinking that the only way you can get diesel in the oil on a TD4 is from leaking injectors?

I don't think so, but is there any way diesel could get into the sump from the injection pump? Rave says its driven by a chain from the crank, but presumably external to the block.

When my 2002 TD4 blew the HP pump seals it fed diesel into the crankcase ventilation and ran the engine on whilst filling the sump with diesel ! Resolved with new pump. So - it can go that way too. Sump filled up scarily quickly. Took ages to get residual fuel out of the exhaust system.

GrumpyGel said:

Am I right in thinking that the only way you can get diesel in the oil on a TD4 is from leaking injectors?

I don't think so, but is there any way diesel could get into the sump from the injection pump? Rave says its driven by a chain from the crank, but presumably external to the block.

Click to expand...

The HP fuel drive is from the timing chain. This requires the pump to be oil tight with the timing case. So if the input drive shaft seal fails, diesel will enter the sump.

Pump input shaft.


Pump mount in timing case.

Thanks Andy & Nodge for the info. Someone asked a question outside of LZ about fuel getting into the oil. My only experience is of the L Series and I wouldn't think it possible on that because the pump is driven by a belt off the end of the cam shaft.

Thinking about my car though - I have a lot of "oil" on the outside of my engine and it is leaving a reasonable mark on the drive - it appears worse around the bell housing. The engine doesn't use oil and the gearbox has been full when I've checked - so maybe it is diesel leaking from the pump which is in that area. I might investigate further at some point, I should also check the IRD, haven't done that for a while.