Fuel smell

[S3 Nattie]

Hi everyone, recently been getting fuel smells if im stationary with the window down and from the exhaust.

The car seems to be drinking fuel bit more than usual with lend me to believe the cars running rich. The temp gauge still at 90 degree, however if the air con is on it sit just below until turned off where it goes back to 90.

I was thinking maybe my coolant temp sensor is to blame for the smell of fuel and lower mpg.

Any help would be great Nathan

 

[bantam1]

Just a thought but when was your fuel filter last changed. Not a standard service item and mine leaked as it hadn't been changed by the previous owner and started to leak as it had corroded after about 55K on the car!

Might not be but just a thought.

 

[S3fan]

I agree with bantam....mine went at 47,599 miles (£37.44 to replace)

 

[S3 Nattie]

Well I haven't changed it and haven't got any record of it being changed so I assume it hasn't.

It located by the drivers side wheel in it. Would it make the car run rich as there is quite a strong smell of fuel coming from the exhaust too.

 

[Nilz]

No its nearer the rear drivers side wheel

 

[S3 Nattie]

Ye meant drivers side rear wheel. Do you think this could be the causes of the problems above. Its only held in place by 2 clips on outlet and inlet pipes of the filter in it.

I was thinking the coolant temp sensor was dodgy and is telling the ECU the cars cold, therefore making the car run rich and me being able to smell the fuel fumes.

 

[jesters3]

Last time I had a fuel smell it was coming from the filler cap area and costing me a future in fuel. Basically a gravity valve inside the fuel tank had fecked up and was building pressure up inside the tank. So fuel was seeping out of the fuel cap and dripping down the side hence the smell. When ever I took the fuel cap off after a drive you could feel the pressure behind the cap and the hissing sound of the airt escaping, if you took the cap off straight away you had fuel gushing out!!! the cost of part was about £5, but meant dropping the rear axle and fuel tank to get to it to change - hence the £400 odd quid bill for the labour. Best way to check if you have this problem is start up the car go for a short drive, pull over with the engine still running and take off the fuel cap; any hissing or fuel spill means the valve is fubar, if all is in order it the next to look at is the fuel filter, fuel lines, fuel pump (under the rear seat) and the engine bay. Good luck!

 

[S3 Nattie]

jester thanks for the useful info. I understand what your saying as I had a similar problem with my previous car. I dont think its that though as I fill up with the engine running sometimes and never noticed anything and its really clean in that area.

I think il give the filter a try first, but not sure how the filter would cause the car to run rich as it would surely be starving the engine of some fuel if broke.

 

[fran-s3]

Dude, take it to a specialist before you end up spending £££ on parts you didn't need! Honestly things like this could be absolutely anything and without the proper testing equipment or know how you could end up wasting loads of time and effort on it like I did... (when my car was running lean, ended doing the exact same thing replacing fuel filter, temp sensor, etc.. Ended up being the fuel pump diagnosed by aps! Take my advice it'll save you the hassle and wallet.)

 

[S3 Nattie]

Thanks for the advice fran. MOT is due next month so will try get it checked over before that. Anyone know want lambda values you should have at idle.

 

[Sandip]

Mine smells rich on start up, runs a bit dodgy too, the fault on mine is the front lambda, once the cars hot its fine, struggled a little on emissions though

 

[S3 Nattie]

I was doing some logging on vag-com and was logging the lambda I think lol. Was 3.1 for quite a while but after a little blast it went down to 1.6. I thought it needs to be under 1 to past emissions test.

 

[finesse]

Any solution to this Nattie? Same issue here!

Especially when fan/heating is on...

 

[steve555]

IIRC MOT limit for lambda is 0.97 - 1.03

 

[Sandip]

Any solution to this Nattie? Same issue here!

Especially when fan/heating is on...

Just a quick one Finesse, make sure there's not alot of oily bits in the engine, i remember the pics you posted showing your breather pipes, when these get warm the oil will heat up and then when you turn the fan on it'll be passing through the pollen filter and into the cabin causing an engine smell.

Give it a thorough clean first and change the pollen filter too if you haven't as they can get pretty filthy :icon_thumright:

 

[finesse]

Just a quick one Finesse, make sure there's not alot of oily bits in the engine, i remember the pics you posted showing your breather pipes, when these get warm the oil will heat up and then when you turn the fan on it'll be passing through the pollen filter and into the cabin causing an engine smell.

Give it a thorough clean first and change the pollen filter too if you haven't as they can get pretty filthy :icon_thumright:

You the man!!

 

[S3 Nattie]

No I havent found the fault. Recently its been smelling pretty strong, as soon as I open my door I can smeel fuel. My mate could smell my car today at a set of traffic light, said it stank of fuel.

Getting really annoying. Had this fault come up couple of months ago. I deleted it and it never come back but im wondering if the lambda sensor is dead as my car is using way to much fuel.

17511/P1103/004355 - Oxygen (Lambda) Sensor Heating; B1 S1: Performance too Low

 

[finesse]

http://www.audi-sport.net/vb/showthread.php?94136-What-does-this-pipe-do!-Part-number-please