Past couple of months my car has been making this low-volume high pitched squeak, almost like one of those high pitched farts

Well anyway it happens when I turn the key on to "full accessories" BEFORE cranking the engine, in other words, when the fuel is being pumped into the engine. I guess that's the best way to put it.

It only makes the squeak for a second or two while the fuel is being pumped(prior to starting the car) and it only seems to do it at random intervals, perhaps after the car has been sitting for a few hours without being started.

Anyway... just a minor annoyance. Just wondering if there's anything I should be worrying about, or any fix for it.

Thanks!

edit - I should mention that it seems to be coming from the engine compartment. Fuel filter is new.