I have a 2003 Gr. Marquis. I am experiencing a high pitched "whine" when I accelerate. My mechanic thought it was the alternator so he ordered another one and replaced it. The alternator was under warranty. The noise is still there. It increases in pitch (gets higher and higher) as I accelerate. Has anyone had this problem and if so what is the fix? Any help would be appreciated.

if it gets worse with engine revs, it''''s a pully. if it''''s not the alternator, check to see if there''''s an idler pully (static pully with no device connected to it) or tensioner pully (spring loaded pully) that may need replacing. if the whine increases with actual speed, it may be transmission related. I can''''t remember which part of the tranny the shop said would make a high pitched whine before it dies, but it''''s a possibility. There could also be a small hole in the exhaust that is making noise, though it''''s usually more of a hiss than a whistle.

edit: also, check the air intake from the air filter out to make sure nothing like a plastic bag or random trash is stuck in the system. that might "whistle in the wind" so to speak.Edited by: slymer

Does the whine also increase in park or only on the road? What is the mileage?

I forgot some info. After the alternator was replaced the noise was gone. This lasted about 10-15 minutes and the noise came back. I think this would eliminate any tranny issues.

Hope this sheds additional light on this.