Hi Everyone, I have a 2002 XK8 and the "check gas cap" warning has been popping up for about a week. I just bought the car recently and have noticed what I think to be a slight fuel smell. A couple of days ago the check engine light came on. I brought it into a mechanic who found a fuel system leak fault code. They "smoke tested" (I think, sorry don't know too much about cars) and found that there were no leaks. They did say that the cannister close valve needed to be replaced.

Based on some research in the forum here, it seems that folks that have had the fuel smell issue have rectified the problem by replacing the purge valve. Do you think the cannister close valve alone could be the reason for the slight fuel smell? Would it be smart to replace both at once or simply just take care of the CCV at this time to see if the situation improves?

Thanks for any advice!

 

I think you need someone more competent with Evap systems. Why do they say the Close Valve needs to be replaced? At first thought, a failed close valve sounds plausible if there is a fuel odor. But the truth is the close valve is normally open to allow air in so the canister can be purged. It only closes to seal the system so it can run a test to see if the tank, etc. holds a vacuum for a given period. No vacuum held = system interprets a leak. The purge valve is the device that applies that vacuum [because of intake manifold vacuum] so the test can be run. If the purge valve fails, vacuum is never applied, so again, no vacuum held = system interprets a leak.

The fuel odor though, tells you THERE IS A LEAK. You need someone capable of finding it.

Good luck!

 

Thought I'd post an update here. The "Check Gas Cap" light and the EVAP System Failure code that were coming up when hooked up to a computer were because of a failure with the EVAP wiring system. I paid about $420 to have this fixed and I haven't seen the check engine light or the "Check Gas Cap" message come up again. The repair was done three months ago.

That said, the "fuel smell in the cabin is still sometimes prominent, even though I did have the cannister close valve replaced.

Some of the other repairs that need to be done could possibly be the reason for the fuel smell I would suspect. Any advice would be appreciated.

Repair list:
Cam Cover Gasket (Leaking)
Coolant Bypass Hose replacement
Engine mounts leaking hydrolic fluid
Rear Engine Seal (leaking)
Power Steering Coolant Hose

Thank you in advance for any advice!

 

Now you need someone with a Combustible Gas Detector to go over the car when the fuel odor is prominent. If you smell it, they should be able to narrow down the location on the car it emanates from. Could be a vacuum hose, leak on the engine that evaporates before you can actually see it, something like that. If you no longer get an evap fault and check engine light, you can pretty well assume the tank system is now sound.

Has it had a fuel filter lately?? I put one on a friends XJR a while back and he noted the fuel smell in his garage. I checked the evap system and all was OK. Then I found an ever so slight leak at the filter connection under the car. Replaced the "O" ring again and all was well.

Good luck!