I have a 1993 Chevy Lumina. After I drive the car for a while, you can hear a loud high-pitched whistling sound coming from the rear of the car. There is also a very strong smell of gasoline. If I remove the gas cap, the sound goes away with the release of pressure. What is causing this issue? Thank you ahead of time!

SOURCE: gasoline smell

MINE DID THIS WHEN THE FUEL PUMP STARTED GOING OUT I CHANGE IT AND BAM FIXED THE PROBLEM WHEN THE PUMP SLAKS UP PUMPING THE COMPUTER TELLS IT TO PUMP MORE AND MORE AND WHEN THE PUMP KICKED IN IT WAS TO MUCH GAS AND FUEL ODOR EGULPED THE INTERIOR OF THE CAR HOPE THIS HELPS

SOURCE: 1984 jaguar xj6

Hello, I have seen many differentials go bad on this model but you saying that the noise went away after you sprayed it with water doesn't make sense. If you want to check the wheel bearings, jack up the car and check the movement of your wheels by grabbing the top of the tire with one hand and the bottom of the tire with other and see if there is too much movement. If there is too much movement, then you need to replace the wheel bearings. (big job)
You also need to check the brake calipers to see if they are sticking. You can take a large screw driver and pry back the pads. They should move back with a little effort. If not, maybe the calipers are sticking.
I hope this helps.
CYA, Gator241

SOURCE: whistling noise in engine and rough idle

check all vacuum hoses,sounds like a leak, try spraying carb cleaner near noise,if engine rpms go up you found the leak

SOURCE: when i give my car gas a whistle comes from the engine. It's a high pitch continual sound. When i let off the gas the whistle stops. It sounds like it's coming from the top of the block.70k miles Thun

Sounds like a vacume leak, chk. for a cracked or broken vacume line or maybe one came off. Does it idle ruff? With it running open hood and listen for a low pitch whistle you may have to rev it up a little.

SOURCE: MPV 2001 burning smell, high whine?

Sounds like either a fan belt or a drive belt needs to be replaced...