Thread: Did You know this 'Can' happen to a diesel (Death by oil)

Originally Posted by isuzurover

Did you read all the posts - Serg has managed to prime it using the hand primer by the sound of it. Would be hard to do that if the diaphragm was split.

yes, apparently better than you did...

Originally Posted by uninformed

sorry if there was confusion, I could NOT get it to prime with the hand primer on the lift pump.

if you like consider my post this way...


what happens If im wrong and you dont check the pump, nothing
what happens if Im wrong and you do check the pump, you've learnt how to check the fuel pump which will aid you in future diagnosis of fueling problems (still a good outcome in my books)
What happens If Im right and you check the pump, you've now fixed a problem
What happens if Im right and you dont check the pump. If you're lucky you'll never get the engine to prime because you cant get enough fuel into the pump to obtain good combustion, if you're unlucky... read your first post again and imagine having to title it something like "I can now claim first and second place on the idiot of the year charts."

the pump is rebuild able if you're lucky its just the valves have been pooched by the hammering the pumps received from the over-rev (I'm not convinced it did over-rev if shutting it down by the electrics worked) most commonly the inlet valve will be stuck open if its not a torn diaphragm. If you block the outlet, put a hose on the inlet and blow in with your mouth, an it leaks air needs repair, If it doesnt you might get lucky and a little love with the small rubber knock-o-meter) might get it working again.

Lets speculate for a second that the lift pump was leaking, you over filled it by a liter or so and you got some diesel leaking in from the pump not much lets call it 250ml-.5l when the engine got up to operating temperature the diesel would have fractioned off (along with some of the oil) and been drawn out into the air intake so a very minor leak could easily be masked by the fuel burning off. This is in the same vein as adding up to 10% of the sumps capacities worth of kero to a diesel when you shut down in arctic conditions, when you start up cold the kero keeps the oil thinned down and as the engine warms up the kero evaporates off leaving you with more or less normal engine oil. The major difference is that when that was a popular thing to do Diesels vented their crank cases to atmosphere and not into the air inlet. (picture a 14l+ 6 pot diesel trying to do a runaway.)

IMO you swap out lift pumps, and most to suit a Tdi/TGV aren't serviceable anyway.
I keep one as a spare as the OE ones (QH ?) weren't known for lasting either, I've found the Delphi one much better, so far.

When the tractor one died twelve months ago I just replaced it rather than put a repair kit through it as a replacement (OEM too) was cheaper.

Remember you need olives and a gasket for it.

and banjo washers and injector washers if you are pulling them for a look see too.