He never I hit the gas, there is a high pitched screech type noise coming from engine compartment...and when I let off gas, it stops...ideas?

 

Probably serpentine belt?

 

maybe try spraying some wd-40 or something like that on the belt. if it quiets down or stops it, you need a new belt. because, it will soon start doing it again.

 

On the belt that's in the front of the engine compartment? Like right by the fan? Sorry I'm not very good with motor stuff

 

And it now sounds like more of a rattling sound

 

oh no! another bimmer. haha. yes, thats it. goes around the pulleys. about an inch wide. i would suggest getting someone to help or just take it to a place and have it done. will not be expensive. the belt cost is around 20 dollars. may take 5-10 minutes to do.

 

AC clutch bearings could have seized. Turn off the AC/Heat and see if the noise stops.

 

Maybe it's the tires...

 

If you spray WD40 on the belt, you are going to need a new belt period.

 

Keep your foot off the gas. Problem solved.

 

I normally think metal on metal when someone says screeching sound, but yes the serpentine belt would also make a screeching noise. A rattling sound usually indicates that something is loose, are you sure you don't have two problems?