There's a loud and constant whistling sound. The noise stops instantly when I accelerate, but comes back when I let off the gas, braking or stopped. I can't figure it out. It's not the pads or coming from the brakes. Seems to be under the hood becuase the sound gets louder when I pop the hood and goes away when I rev. Any help would be greatly appreciated. Thanks in advance.

 

do you have a cai?

 

I actually get that too, but for me it sounds like its coming from the back.

Try this, next time it starts to happen turn off your head unit and see if it stops. It does when I shut mine off. I think it may be something to do with the antenna. Thing is it never starte to happen until after I had my subs installed.

-Ian

 

Yeah, I had a similar whistling sound before which only sounded when I accelerate but it was just a bad ground when I installed my amp/sub and I resolved that prob but this is much louder and coming from the front somewhere. I can't pinpoint the source but guessing somewhere under the hood.

BTW: Redmax, I have just a cone filter not cai.

 

does it go away when the car warms up fully? or is it constant even after like 30 minutes of driving?

is it a whistling noise or can it also be described as a whine?

 

My buddy had the same problem with his explorer. The big loud whine is most likely from your intake. Its just set at a bad angle just like if your blow at a certian angle into a beer bottle. The air is being fed into the pipe at an angle which makes noise. Just hit the intake once or twice.

 

my theory had two possible solutions:
a. the normal whistle you get with the cai
b. if more extreme one of the connections may be loose and it could be a minor air leak, i had a leak about a week ago and was able to fix it by adjusting the piping where you could just adjust the clamp to make sure its tight

 

my friends intrepid had almost the same problem. turns out it was his belt tension pulley that went out.

 

belts problem. i experienced the same thing too

 

It seems that the sound starts about 5 minutes into driving. I took the car to a nice and quite area to check the problem further and it does sound like it's coming from the belts. Couldn't really say for sure since it's a really hi-pitch whistling sound (like when you put a mic up to a speaker) and a few minutes of listening to it closly under the hood really irritates your ear