fuel smell in oil

[jackson74]

hi, wondering if anyone can help?

its a 2003 S40 1.8 sport

my car went into the garage today for a new timing belt & pulley, new thermostat, and oil/filter change...

I'm having the work done with a Volvo Specialist and got a call from them stating they could smell petrol in the oil, they checked the injectors and said they was dry and no leaks there, at this point they are unaware of what is causing the smell? also a few months back i got a full service done at another garage and apparently it was over-filled by an inch

i do very few miles in my car, and only use it a couple of days a week so it just sits there most of the time and when i do use it i'm only doing short/local trips.

i have no problems starting it, no loss of power, no idle issues or things like that if any of the above is any help?

does anybody have any idea? help would be appreciated, its a little worrying.

the garage has suggested not to carry out the new timing belt/pulley repair until they can figure out what the smell is, instead suggesting to just have fresh oil/filter and give it a couple of months of driving to see if the smell comes back?

[Simmy]

short journeys are not good for any car when the car is started the fuel mixture is increased same as pulling the choke on an older car it possible that this is your problem how short are your journeys? it might be doing this if your journeys are less then 4 miles .it might be worth having the injectors checked to see if they are working correctly.

[jackson74]

Originally Posted by Simmy

short journeys are not good for any car when the car is started the fuel mixture is increased same as pulling the choke on an older car it possible that this is your problem how short are your journeys? it might be doing this if your journeys are less then 4 miles .it might be worth having the injectors checked to see if they are working correctly.

yeah my car basically only does 10-15 miles a week (sometimes even less than that), as i needed it to visit my mother as her health took a bad turn, and living/working in the same town i didn't need it for work, so most of the time its just sat there parked up,,, which seems to be the general thought of the volvo specialists that i'm having the work done ie short journeys... they did say that they checked the injectors and seems to be no issues? although not sure what checks they actually did?

just a little worrying that a Volvo Specialist can't pinpoint the issue, hence the post in the hope someone has had a similar issue

[Simmy]

which volvo specialist did you use ? its unusual for a good volvo garage to fail on finding faults.

[Kev0607]

All engines have slight blow-by, gasses that escape past the piston rings and flow into the crankcase where they mix with the oil. When you start your engine cold, the computer commands a rich mixture and some of that fuel doesn't burn and ends up in the crankcase.

If you drive short trips and never get the engine hot enough to evaporate that fuel, you end up with a petrol smell in your oil.

Although, petrol in the oil isn’t good. Your engine needs lubrication that only the oil can give.

Needs a service (oil change) and a good drive. That’s the cheapest option at first. If it still smells like petrol after new oil and a decent spin, something else is wrong. Likely injectors, which can’t be tested by simply looking at them.

[nokinnikon]

Originally Posted by Kev0607

All engines have slight blow-by, gasses that escape past the piston rings and flow into the crankcase where they mix with the oil. When you start your engine cold, the computer commands a rich mixture and some of that fuel doesn't burn and ends up in the crankcase.

If you drive short trips and never get the engine hot enough to evaporate that fuel, you end up with a petrol smell in your oil.

Although, petrol in the oil isn’t good. Your engine needs lubrication that only the oil can give.

Needs a service (oil change) and a good drive. That’s the cheapest option at first. If it still smells like petrol after new oil and a decent spin, something else is wrong. Likely injectors, which can’t be tested by simply looking at them.

Absolutely the correct answer kev.

no regular short journeys are good for a any vehicle. You really need to go and blow the cobwebs out it will cost you in the long run otherwise.

[loelly]

If oil level was to high befor, it is also possible they did not overfill but fuel came in the oil and the level got higher. So oil + fuel gave an inch overfill and not only the oil. If so have it checked again after the service now.If level go up again there i a big problem that need to get fixed soon.

[jackson74]

just got a call from the garage.. it was a the broken thermostat, tricking the engine thinking it was running cold all the time and using extra fuel hence the smell in the oil, so all is well again and no major engine problem phew!

[Kev0607]

Originally Posted by jackson74

just got a call from the garage.. it was a the broken thermostat, tricking the engine thinking it was running cold all the time and using extra fuel hence the smell in the oil, so all is well again and no major engine problem phew!

Good result. Which specialist did you use?

Are you having the timing belt replaced?

[jackson74]

Originally Posted by Kev0607

Good result. Which specialist did you use?

Are you having the timing belt replaced?

It was Trevor Burgess in Hyde, and must say very happy with there customer service and keeping me informed, i can't speak highly enough of them.

yeah initially that's why i took my car in to get a new timing belt and pulley as it was due a new belt, plus it was making an constant/intermittent noise which is common on my model and its because of the pulley which causes that noise.
I will add that within seconds of me pulling up into the car park the mechanic came out and without me asking he told me what was wrong with it lol