Thread: Fuel smell in engine oil

This isn't on a Land Rover but rather a Honda Integra. Lately the car has been shuddering when under load and particulary when doing 100 on a highway going up a hill.

I checked the oil on the filler cap to see if there was any water in the oil and noticed that the oil now has a very strong smell of petrol.

What are the likely causes of petrol smelling oil? I don't know enough about engines but was thinking that it could be related to the head gasket.

Does it have a diaphragm type mechanical fuel lift pump? Maybe there is a hole in the diaphragm.

Of interest: Heard of a problem someone had with an old truck that had more than one mechanic baffled until this basic cause was pointed out by a bloke who had seen it before.

No problem when this truck was started cold, but every time it was started with motor hot POP! The distributor cap was blown off. Replace it and motor then ran as normal.

Bloke who had seen problem suggested sniffing oil on the dipstick. Smelt of petrol, caused by leaking fuel pump diaphragm. With motor hot, crankcase was full of petrol vapour. Enough of this would get into the distributer between the worn shaft and bearing to form an explosive mixture with air already there. The first slight arc across the points when starting the motor was attempted ignited this, blowing the cap off.