Engine oil smells of petrol

[GuinnessMK]

SWIMBO has a 1.2 petrol Punto on an 07 plate.

It's seriously low mileage, and she only uses it for the school run and her commute to work, about 1 mile and 4 miles respectivley. (I know save the planet, walk / cycle). No issues at all running wise, fuel economy is OK, no visible smoke, no oil consumption.

Recently it's started smelling really strongly of petrol. I've been underneath it today and there are no obvious leaks from the tank / filler / pipes from back to front / checked all the hoses in the engine bay, took the air filter out, took the air box off, visual and finger test of the fuel rail and injectors. Nothing obviously wrong at all.

Took the oil filler cap off and nearly fell over due to the smell of petrol.

I changed the oil and filter a couple of months back. On removing the dip stick it still looks fresh, clear yellow and is at the right level. However it did wick into the kitchen roll a bit quick...

I'm wondering if the combination of short runs and winter / cold starting has led to it flooding / petrol getting past the rings into the sump?

So, do I swap the oil as a precaution? Anyone think of any other things that might be wrong?

[stevieturbo]

If the oil level has not changed, it's unlikely to be full of petrol.

And modern cars generally run quite lean, so it would be difficult to see how excess fuel could ever make it's way into the oil on one without some other noticeable symptoms. Like say going from 40mpg to 10mpg with a matching deterioration as to how the car drives.

What do the plugs look like ? What does a compression test show ?

[Mr2Mike]

stevieturbo said:

If the oil level has not changed, it's unlikely to be full of petrol.

And modern cars generally run quite lean, so it would be difficult to see how excess fuel could ever make it's way into the oil on one without some other noticeable symptoms.

They run lean when fully warmed up, but any spark ignition engine has to run somewhat rich when cold and doing only a few miles in winter probably means it never warms up properly.

[stevieturbo]

Mr2Mike said:

They run lean when fully warmed up, but any spark ignition engine has to run somewhat rich when cold and doing only a few miles in winter probably means it never warms up properly.

Ive yet to see a modern engine that isnt quite happy around 13/14:1 during warmup.
Certainly not rich enough to cause any problems. There would need to be something horrifically wrong for it to be so rich as to see fuel in the oil.