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Hi everyone.

I have a problem with the smell of fuel when I stand next to the rear drivers side of my RS4. Its not detectable from anywhere else on the outside of the car, and I have stuck my face well and truly under the bonnet removing covers to examine fuel rails and plumbing - and nothing there either. No leaks are apparent when I stick my nose in the fuel cap cavity either - pitty, always wanted to get high on fuel smells

I have also had the car up on the hoist and no leaks detected from the filter, although I can detect the smell when standing under the fuel tank. No leaks or smells detected along the fuel lines up the side of the underbody either.

By process of elimination, I can only therefore suspect it may be a leak from the top opening to the tank. Can anyone please advise the best way to access the top plug and plumbing - do we need to remove the tank?

Have I missed anything else that is worth cheching first? The filler snorkal perhaps - how do I check this?
Has anyone else had this problem ?

have a search there was a topic on here or the s4 forum about this problem.

Hey Gb... the other possibility is that the fuel is a bit rich and its unburnt fuel coming through the exhaust system. I'd check that out before pulling things apart.

Same exact problem here.
If you find the topic about this, please share.

Thanks

Have you checked the top of the fuel filter? Also have you turned the ignition on so the pump runs whilst under the car?

Just a thought...

we had this....

it was the filter leaking pressurised fuel out.

run the engine and look under in front of the driverside rear wheel, you should see a fine mist of fuel...WHEN THE ENGINE WAS OFF i couldnt see where it was coming from either.

this was rectified with a few filter at a cost of about 15 quid.

Thanks Guys.
Changing the filter is the first thing I did (sorry, should have mentioned this). I have had it up on the hoist with motor running and no visible leaks.

Is it possible there may be problem with the plumbing 'upstream' of the filter towards the top where it feeds into the tank ?

Its not unburnt fuel in the exhaust as the smell is still apparent - albeit not as strong - when the car has been sitting around for a few days.

I will try a search and see what I come up with.Let me know if you have any other thoughts on the subject.

Searches didn't bring up anything further than discussion on filter deterioration and leaks.

I did find mention however, of a button just inside the opening of the filler neck.
Can anyone tell me what this is for, or anything about it at all ???

Yes, it release the air that gets trapped inside the filler neck/tank - press it with the filler nozzle once in a while (toward the filler neck) to release

Probably find you'll get more fuel in as well...