Nickshu

Hey guys, I get a fuel vapor smell in my GT3 coming from the car after I come off the track with everything hot. It persists about 20 minutes after the track session then dissipates. It seems to be worse when the fuel level is at or below a half tank. It seems to be coming from the left (drivers) rear wheel area. I cannot smell any fuel in the engine bay. I don't see any fuel leaks, have no issues filling up with fuel, and no CEL. I have all records on the car and the only thing every done to the fuel system is the fuel pump was replaced at a Porsche dealer in California when the PO was on a road trip and the pump died, fuel filter is original. Car has 26K original miles. The factory diagrams I can find of the vapor/evap system do not appear to be very comprehensive (??).

Any ideas on cause/solution?

Thanks in advance!

Stephen Tinker

Nick, is there any fuel smell if you lift the front hood where the fuel tank is situated under the battery?
The fuel lines run from the tank under the L/H side of the car to where the filter is located in the engine bay. Check the filter push on connections (its not too difficult to replace the filter either) but if the filter was faulty you would expect to smell fuel whatever the tank level was or track or road driven....

Anthony Lovero

My car did this after the Tommy OG lap last weekend at COTA.

Same thing, it wasn't a problem until the fuel level was below 1/2 tank (this is when the fuel gets hot AF). It was a problem for me about 2 years ago, but I disconnected/cleaned all of the evap lines under the right wheel liner and it went away for awhile. Now it came back.

I'm going to pull down the wheel liners again this week and see if I can find some sign of moisture around the evap canister / lines. I've heard this smell happens when the vapor canister fills with fuel.

Nickshu

Thanks Anthony. When you "cleaned" the evap lines what did you do? Cleaned the connections and o-rings and lubricated?

I don't smell anything up by the fuel pump or full filler area. It's usually windy at my home track so it's tough to nail down where it's coming from when it happens...and obviously I can't reproduce this in my garage at home. I do think that it's coming from the rear of the car, but not in the engine bay.

Anthony Lovero

I just unplugged the connection, wiped the male end with a rag, and blew in and around the female end with compressed air.

Honestly, I'm not sure how relevant of a fix this will be. When I examined them last time, I saw one of the fittings had dust accumulated around it as if it was slightly leaking. This is what makes me think it was the culprit. I don't know if I would take everything apart unless I saw something that would be a potential source of the leak/smell. You would think that a problem in these systems would be a source of the smell though, so I think its a good place to start.

Nickshu

I have read elsewhere how hot the fuel can get in the return system. I wonder how much being at altitude (Colorado) effects that as it would lower the boiling point of the fuel somewhat.
I think the purge valve dumps excess fuel vapor into the intake/air filter boot right? Strange that I don't smell it in the engine bay. Need to study those diagrams more.

Anthony Lovero

One more:

Welty

Same issue. Thank you for the thread. Have not been successful to date with a solution.

spiller

Why is your fuel filter "original" still? They are supposed to be replaced every 6 years or 40K miles from memory. Not to do with the issue but i'd replace it if you never have!

Nickshu

I am pretty sure it's original. I was going to replace it this past winter, along with preventive replacement of the coolant tank, but I did not get to it. Thanks for the reminder, I was unaware there was a 6 year lifespan....so I'm at more than double that! I agree it's likely unrelated to the vapor smell however.

Nickshu

Thanks for the reply. What have you tried so far?

spiller

Dont feel too bad about it! The filter on my cup was dated 2005 before I replaced it last month. No significant difference noted but seems to start a little easier.

Anthony Lovero

The coolant tank is a good job to do at the same time as the fuel filter. You will have more room to work on the coolant tank with the fuel filter out. I did mine a couple years ago, it got cooked and cracked.

If you pinch off the hoses around the tank (after emptying it), you don't need to completely drain down the entire cooling system for that job. FYI, I had to unbolt the motor mounts and lower the engine slightly to get the coolant tank out.

TurboCup87

I had persistent fuel smell after fill ups and with track driving. It was the rubber gasket for the fuel pump cover. Pump had been in and out to check and change the problematic hoses on the pump. The gasket is probably reusable, but mine didn’t work well enough. No visible leaks, just odor.

Nickshu

I was at the track this weekend and investigated further. There is definitely no fuel smell from the fuel pump area. Nothing in the engine bay. It all seems to come from the left (driver's) side rear wheel well area. Are any of the Evap lines in that area? The diagrams suggest they go more on the opposite (right) side??