Diesel fuel in engine oil Bobcat 873

[Avannah]

Diesel Fuel in Engine Oil Bobcat 873? Hello. I have a bobcat 873 with 3400 hours. The machine began billowing black smoke when using it yesterday. I checked the oil (which was recently changed) and there is a ton of diesel fuel in it (the dipstick was 90% full - way over full). The engine also didn't want to shut off (runaway situation?). Have looked around, and a lot of people seem to suggest a lift pump, but I would like a little more info on what can cause diesel fuel to leak into the oil on this machine and cause the over run. Thanks! Matt

 

[Bobcatdan]

Fuel transfer pump 99.9%. I have also seen them leak backwards and pump oil in to the fuel. Whenthe oil becomes that deluted with fuel and that over full, it can run off the fumes of the oil. Some duetzs had pcv system which returns crankcase fumes to the intake. Change the pump and engine and you should be ok. Altho not great, fuel is better in the bottom end then coolant.