sebnagy22

I opened my engine oil cap and I can smell petrol/gas when smelling inside or when smelling the oil cap. Is the smell normal? The car does sit a lot and a lot of the time it is driven short distances.

I previously had an issue where oil was coming out of the oil cap due to a breather pipe issue but it has now been fixed. Booked in to get the oil changed in a few days.

What are your thoughts?

Thanks

JohnEnglish

Yes, that's to be expected with lots of cold starts and driving short distances. The engine is unable to come up to operating temperature and burn off the hydrocarbons. You should be changing your oil more frequently since it's being diluted.

sebnagy22

Recently I have driven longer journeys where the engine has reached optimal temps. Shouldn’t the smell evaporate from the oil if the engine comes up to operating temperature?

A4Audi4Fun

How recent? Yes the longer journey may have cleaned things out but it probably only takes a few short trips (timewise, how long are yours) for your nose to smell petrol again. If driving less than 5000 miles per year, definitely consider more frequent oil changes.

JohnEnglish

Depends, are you looking at the engine coolant temperature or the oil temperature? You need to drive long enough so the oil gets up to temperature too and stays there long enough to burn off the hydrocarbons.

sebnagy22

Looking at the oil temperature, I recently done a 100 mile round trip and it still smelt like gas/petrol after it when the engine got cold.

JohnEnglish

As mentioned above, it could be that there's so much build up that it hasn't all been cleared out or you're starting to get sludge. After you get your oil changed, see what the oil smells like after several long drives.

Nikon1

Or, have the oil currently in your crankcase analyzed before you have your next oil change. There are a number of reputable firms that offer this service.

I personally use Blackstone as my lab of choice. They have been around for a number of years and have a solid reputation.

— John