ok first off i have a 1998 Audi A4 1.8TQM Sport. the car was runnin fine until today. all of the sudden i drop my windows and i hear this really loud whining sound. at first i thought it must be something else but i turn my car off and the sound goes away. at first i thought it sounded like something electrical but while the car is in the on position, no sound. as soon as i turn the car back on sound comes back. if i let it sit for a while and then turn it on it takes a little while for the sound to return. now heres the weird part. it sounds like its comin from either the bottom of the car in the middle or a little bit more towards the back. kinda hard to tell. also when i shut the engine off i hear kind of like a gurgling sound. its kinda hard to explain the sound but it sounds really low and gurgly. does anyone know what is causing this? i tried searchin but to no avail. thanx for any help

 

bottom? whining? maybe your turbo is going...

 

Id say check the fuel pump

 

+1 for the fuel pump. pop your trunk when it happens and listen inside. If its real loud in there its most likely the fuel pump.