hi, i have a c7 engine that keeps filling the sump with diesel,we have changed injector seals but that didn't help.now thinking transfer pump,anyone had this problem or got any ideas?
Probable Causes Leaking seals on the case of the unit injector or on the barrel of the unit injector. Excessive leakage from the unit injector tip or breakage of the unit injector tip Cracked fuel supply manifold Leaking seal on the fuel transfer pump. Ensure that the weep hole is not plugged. How is the engine running? Did you check the fuel pressure? How many hours? Did you use the new backup rings with the O-rings on the injectors? A machine serial number may reveille known problems.
fitted new o rings and back up rings,injector tips looked ok,will check other things on monday. thanks for reply
Make sure the weep hole between the transfer pump and heui pump are clear of any obstructions, if the pump leaks it should drain out that way. In fact it is far more common for the heui pump to start leak engine oil there than the other way around. How quick are you filling the sump?
it seems to run for about 10 days then oil pressure light comes on
Have the engine been tested with ET and a cylinder cut out test to determine that all injectors are working properly?
doing ET tests on monday,will know more then cheers ukmart
I just recently had a fuel dilution problem on a C15. It had been fixed a few time with new injectors and seals but still did it. I blocked off the return at the back of the head, pumped up the priming pump from a bucked of dyed fuel and watched around the injectors. found #5 was leaking and then inspected the head to find it was out of round, it was machined wrong from factory. Ended up with a new head.
after about 10 hours the sump was all disel again.we performed the cylinder cut out test and the results were ok. the weep hole was not blocked. ET showed low fuel pressure 127 times,if it was transfer pump would it leak from weep hole rather than fill the sump? help!
Can't be the transfer pump, it has no direct connection with the engine oil system other than passing by the weephole. Plug off the fuel outlet and inlet on the head and pressurize, there must be a leak there somewhere with that rate of dilution. You might be able to see it with the valve cover off.
thanks all for the help.we pressure tested the fuel rail in head and it was ok.we then changed the injectors about a week ago and it has worked ok since.now the cab heater is not getting hot!
If it is leaking between the transfer pump and heui pump can this be fixed by replacing the transfer pump or does the entire heui pump needs to be replaced?