car whines when at idle almost sounds like a dentist drill?

Question

I put this question in and got 4 answers. I took the car in and had it looked at by a mechanic and they fixed 4 other things on the car that needed to be fixed but said they couldnt reproduce the sound. So they didnt fix it. I dont know how they couldnt reproduce it expecially since I still hear it everytime I drive the car. I still think that its the alternator. It is louder when I press the brakes. but sometimes its there sometimes its not. I cant figure out what its coming from though.

sorry I drive a 91 camry with about 120,000 miles on it. just had the brakes fixed the cv boot the head gasket replaced but none of this fixed the problem.

Answer 1

The reason it seems to get louder when you push on the brake, is because of the added load to your electrical system from the bright brake lights comming on.
Same with turning on your headlights, or rear defroster.

In some electrical systems, they install noise supression chokes in the alternator. Others are in the radio, and some still are in the electrical wireing.

I'm not real sure which one is on yours however.

Just for fun, remove the "radio" fuse from the fuse box to see if it goes away. If it does, it's in the electrical system and the noise is coming thru the stereo speakers, even though the radio is off.

I don't know how much this helped, but at least I tried.

Answer 2

with my experience, depending on how old your car is, and you think it might be the alternator. check your pulleys and belt. you said you hear it when you hit the brakes sometimes. i don't know what kind of car you have but newer pickup brakes run off the power steering pump. if the nose happens in the morning when you first start your car. it could be the belt(s) , or you have bad pulleys.

Answer 3

i dont know man...