Recently I've noticed that when I fill the tank on my '99 OBS beyond 3/4 of a tank I get a strong fuel smell for a couple of days.  My first thought was a rusted filler neck (that happened a 4-5 years ago and was replaced) but it doesn't look too bad. I'm not getting a CEL or any pending codes either which if I remember correctly a leak in the filler neck/evap system will cause one.  I don't see any fuel on the ground or running down the tank anywhere either.  I've also noticed that if you take the gas cap off there's a strong fuel odor that comes flying out of the filler neck regardless of how much fuel is in the tank. It seems like the fuel fumes are just building up in the tube.  
Neither of our other Subarus have that problem.


Before I start shotgunning parts I was wondering if anyone had tackled something similar before.  The fact that the fumes seem to be piling up in the filler neck leads me to think it's the canister, vent valve or solenoid but my car doesn't take a long time to fill up.


 

Thanks!

 

Edited January 27, 201511 yr by Husker

usually folks get evap codes with evap problems but, it sure seems like a bad/clogged Purge valve or similar.

 

in very cold weather, some of the fuel systems clamps underhood can leak....

 

interesting

Try tightening the clamps on the fuel lines in the engine bay. The fuel smell (especially during cold weather) often comes from the lines and creeps through the firewall.

Try tightening the clamps on the fuel lines in the engine bay. The fuel smell (especially during cold weather) often comes from the lines and creeps through the firewall.

 

I've had that problem before too, replaced the clamps and a hose a couple of years back.  However, is definitely centered around the rear quarter panel area where the gas filler/canister is. The car lives in a garage now so it doesn't see terribly cold overnight temps.  There isn't a terribly noticeable fuel smell in the car, just around the filler neck area.

charcoal canister might be flooded, gas cap seal cracked (but, seems like you get pressure build-up in the tank so, not likely), evap hoses loose/cracked, etc.

 

there should not be any significant pressure differential in the tank if the various fill and purge valves are working correctly. While rare, some people get spiders clogging evap drain hoses.