Kubota engine-diesel fuel in oil?

[twinbird]

I have a mower with a 37HP kubota engine and all of a sudden there is diesel fuel mixed with the engine oil. I'm thinking it is a head gasket problem,is there any other way fuel can get in with the oil? Thanks for any input.

 

[Marlowe]

I'm no diesel expert by any means, but I'd bet against the head gasket. Just can't see how it could let deisel into the crankcase. I'd lean more towards an injector stuck open. The excess fuel would eventually leak by the rings ending up in the crankcase. I've seen it happen often in gasoline engines with a flooding carb.

Tom

 

[inveresk]

See this thread for a possible cause . . .

fluid in oil

 

[joecdeere]

I'd be looking more to the seal on the injection pump to the engine or if it has a mechanical fuel pump on the engine, that it has an internal leak. Please don't run engine until you find the problem!

 

[twinbird]

It has already been ran. I was out of town when it happened and the crew ran it, it overheated so they let it cool down and parked it in the shop.I don't know if the fuel in the oil and the overheating are related nor do I know which came first but whats done is done.When I drained the oil today it was like water coming out it was so thin. I hope not too much damage was done.

 

[hudr]

I'm with Marlowe. I'd look into an injector issue. We have had injectors hang open and run fuel into the cylinder. It washes past the rings and ends up in the crankcase. It WILL lead to ring failure if not addressed soon. Also, as you noticed, it will thin out the oil making it useless as a lubricant.

 

[JerryG]

Like Joe said check the pump. Most injector pumps have a seal that will leak fuel into the crankcase if it goes out.

 

[twinbird]

Yes after further review I don't believe its the head gasket.( I was thinking antifreeze in the oil).I'm checking the lift pump and injector pump.