Slight fuel smell, front wheel arch....

First post of the new year so happy new year and all that... Anyhow, parked up my 03 C4S in the garage after a trip out on Saturday and caught a slight whiff of a petrol smell near the OS Front Wing. After a thorough sniffing around its coming from under the wheel arch. Had another sniff around on Sunday morning and it had cleared but after taking it out again the smell was back. No evidence of any leak on or under the car and i'm 99% sure its not the fuel cap, as there was no smell around the edge of cap, whereas under the wheel arch there definitely was. Couldn't detect much of a smell under/around the battery so my initial thoughts are Charcoal Canister of the plumbing around it..... Searched the forum/google and this seems likely but one question i have for those that have seen (smellled?) this before is, when I take out the arch liner and have a look am i likely to see any visual leaking or will I be relying on my nose to pinpoint the issue? As ever, any guidance gratefully received.... Thanks all!!!

In my case smell was strong after refuelling, fuel filler pipe has been at fault you can see on picture how I welded it, it wasn't visible as these are on "TOP" of pipe. It is easy to put apart and to put it back together, if you decide to take pipe out you have to buy new gaskets,

I think in your case i would be jacking it up , wheel off and arch liner off just to have a look .. i doubt you will see anything and it depends on how far you want to go as the filler pipe can be removed and inspected .. as above a hole is possible .. The carbon canister and relevant pipes are all there .. i think i would just have a visual look and a sniff around to make sure its not an actual leak . A slight smell in that area when in a garage is not a big deal .. but better to be safe just in case there is a small leak somewhere .

Definitely. I had another look (smell) tonight after it's been parked in the garage for 24 hours and there is only the faintest of petrol odour under the wheel arch and very slightly around the cap (cap rubber looks 100% fine). So if it is a leak then it's when it's running I think. Wheel off and liner out this weekend (weather permitting) to have a better snoop around. Thanks for the advice as always!

Hi, you say you have checked your cap?? Mine was the same in the garage, smell of fuel when I go in there. I replaced the cap and it worked. Cheers

Yeah, the cap looks to be in good condition and the smell appears to be coming from under the wheel arch but I'll bear that in mind when I dig a little deeper this weekend. Cheers!

Have a look but to be honest i doubt you will find anything .. piece of mind though .

Interested to see how you get on. I had the same symptoms last year, and ended up changing the carbon cannister. Seemed to solve the problem until I refilled the tank and the smell in the cabin/around the o/s wheel arch reappeared when running. Once its been left in the garage for 24 hours it is difficult to detect anything, which makes me think it is related to running/system being pressurised rather than a leak per se. I havent replaced the fuel cap yet, but for the cost I probably will just to remove that variable. Pin holes in the fuel filler pipe as per above is a new-one on me, so I may ask the indy to have a look - given the corrosion elsewhere on the car (brake pipes & steering rack replaced during my ownership) it wouldn't surprise me... For now though, I have SORN'd the car until the weather picks up.

Maybe its a polar silver C4S specific quirk?! :floor: Finally managed to take a better look this afternoon and dropped out the wheel arch liner. As demort predicted nothing really obvious, no signs of a leak and the smell only shows up during/after running. The only thing I noticed was that the top manufacturing joint of the charcoal canister seems to be slightly separated (picture below). Could this be the culprit? Anyone know if this is what happens when they go bad? The fact that it was blowing a force 9 gale up the drive and then went dark curtailed any further digging. Oh well. Thanks all!