Tootsall

Yesterday I was "out and about" in the afternoon (buying paint for some redecorating). Got home, parked the car in the garage. About 3 hours later while working on something else in the garage I thought I heard a very faint (almost subliminal) "buzz/whine" sound. Checked all around for the source and finally determined it was coming from the back of the car. Opened the trunk and fuel filler lids and listened more closely...sound was definitely originating in that general area, louder around the filler lid. When I shut the trunk...the sound quit!...I've been out a couple of times since and now check for that faint sound after I park...nothing so far. Is it possible that there is a fuel pump relay or some such that can hang up and keep the pump running even though the ignition is off? If so, it might be the cause of the previously unexplained loss of battery power I experienced earlier this winter. Should this be the case, where is the relay located for the fuel pump?...or is it integral with the Fuel Pump ECU in the back/left panel?

lesz

I might not have my terminology 100% correct, but there is a fuel evaporator system that purges and recaptures unburned fuel vapors before they can escape into the environment. The system normally becomes active several hours after the engine is shut down, and you will hear that low level buzzing sound for several minutes.

I'm virtually certain that that is what your heard, and it is completely normal.

Tootsall

"Whew", and I sure hope that's what it is. Thanks for the speedy response. In related news... the guy at the hardware store (an "essential service") advises that paint is flying off the shelves...seems everybody is finally getting to their "honey, do" lists. Cheers.

lesz

Normally, most people would not even be aware of the system unless they happened, by chance, to be in the garage at the time when the system was operating a few hours after the engine was shut down. And, if the car was parked outside, there would likely be enough ambient noise that you wouldn't even be able to hear the sound of the system operating.

Tootsall

So I can tell my wife there's nothing wrong with my ears... she mumbles.

Poppa

I've heard that as well... several times if I've stepped out in the garage late at night when everything else is quiet, I have noticed that "whine" sound as well.

Lexmart

Good, it's not just me. I've heard that once or twice before as well. Did scare me a bit though.