2005 Prius - smells like gasoline after lengthy stop while AC is running

Hi - I've had the car for 130k/2 yrs, and been very happy with it. Will definitely buy another.

That said, I'm puzzled. Yesterday and today, after it had run for 10-20 minutes at surface-street speeds (so was warmed up), I got stuck at a lengthy traffic light and noticed a distinct smell of gasoline - not other cars' exhaust, but a fuel smell coming in on the blown air in the cabin. I have done no mechanical work on the car, or spilled gas into the glove box, or something else that would cause this, so I'm confused.

In each case, I switched the AC off, rolled the vent to exhaust, and it cleared within 30 seconds. Turning the vent back to recirc - no smell; turning the AC back on - no smell, even at subsequent shorter stops.

It's not leaving pools of fuel under the car, and I'm not seeing any leakage in the engine compartment.

Suggestions (beyond not running the AC, which isn't reasonable given the 90+ degree temps here in CO lately)?

 

No - I do not smell gas any time but those two specific instances, air on, with or without A/C. After the two instances, I put the blower to blow through, cleared the pipes and the cabin of the gas-smelling air, then switched first to recirculating air (still no gas smell), then turned on the AC with recirculating air (no gas smell). It really seems specific to prolonged idling at a stop.


I should add that we are relatively high-mileage weekly, and the two instances were separated by 50+ miles of event-free commuting, with stops and drives of up to 70+ MPH, so I really have not seen the problem manifest when under drivetrain load. It really feels situational, that the AC or the ventilation path draws in fuel vapors but only when it's at a stop for a prolonged period. I just don't know sufficient systems layout to have any knowledgeable guesses. While I am all in favor of "fire=bad", this really doesn't seem to be a gas fire risk, so much as it does a lower-risk ventilation and cabin cooling problem.

 

And if I have to I will go to get it checked, but money is tight enough that I wanted to see if there was something that I could figure out for cheaper.

We *have* had a minor gas issue a few weeks ago, with a filling station having its pump "kick out" (where the fill latch disengages and the pump stops filling the car) and not be willing to put gas into the tank beyond about a 5-6 gallon level, when I knew from the gauges that the car had less than a gallon left, and should have taken 8-9g. So it may be related - I blamed it on a hyper-sensitive pump disengaging before this.

I really hope it is just a bad tank of gas - otherwise, we've had no problems for about 50k miles, and I'd really like to not put into dealership hands for the costs involved.

Thanks to Bisco and WJTracy for their insights!