Contour Enthusiasts Group Archives Forums General Troubleshooting whistle coming from under the hood

i can hear a high pitch whistling noise coming from under the hood when i'm driving. i can hear it in all of my gears at all speeds, but more apparent in 1st and 2nd cuz of lower speeds and less road noise. I hear all the time under normal driving around half an open throttle, I don't hear it under full throttle or when i take my foot off the accelerator.
I know its not the iddler pulley just had it replaced this summer. i also replaced belts this summer
Could this be a TB problem? I had this problem for a while now with my stock TB and with the 65mm TB. It getting worse with time and its annoying the living out of me.
Or could this be a leaky vacuum hose? if it is, how can i find the leak?

I do not know if this is the whistle you are hearing but if you have the stock air box i think when it is sucking in the air it gives off a little whistle??

Ahh i see you have SCA cold air intake. I have this "problem" also. It seems to whistle more than the 7 dwarves! I don't think it's hurting anything but can get kind of annoying.

i have the SC cold air intake and K&N filter. the noise was there with the stock air box and the now with the CAI and K&N. it does sound like a whistle coming from air getting sucked in
I'm not sure whats the source is but it is related to the throttle. it starts low and gets louder as a step more and more on the gas but when i punch the pedal all the way down the noise is gone.
I ruled out the air box, TB, pulleys and belts; all of these parts were changed.

the whistle was there before i installed the intake but got worse after i installed it.
Does yours get louder as the throttle opens and go away with wide open throttle.

How loud is the whistle at idle? Does it seems to fluctuate somewhat with rpms, with the sound getting slightly louder and slightly higher pitched as rpms increase? Do you get the sound right away when you start, or does it take some time before you can hear it?

I think you and I have the exact same whistle. I don't know about full throttle, but I have all of the other symptoms. When I had it at the dealer to replace the idler pulley I had the mechanic listen to the sound. He was almost positive that its a vacuum leak, and he said that there wasn't much he could do to find it until it threw up a CEL. I asked if it would cause any problems, and he replied that its not really an issue unless it gets bad enough to cause a CEL. He said that to find the leak, he could try spraying carb cleaner at various points which would cause the engine to rev higher if the flammable liquid gets into the intake system through the leak and ignites with the fuel.

It takes about 15 minutes of driving around before I can hear it, presumably because the break, wherever it is, doesn't open up until the engine gets warm. I have to admit, it gets very loud and very annoying, but I can't afford what it might cost in labor to have someone tear apart the engine to find it.

there is no noise at iddle.
i don't get when i start up the car only when i'm driving.
about throwing a CEL well my dash looks like a christmas tree. the CEL goes on and off all the time thats because of my exhaust i dont have any cats. So i cant tell if it is throwing a CEL.
I'm going to try spraying carb cleaner to test for leaks, thanks for the advice.

Originally posted by abwamo:

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I'm going to try spraying carb cleaner to test for leaks, thanks for the advice.

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Be careful with this. I wouldn't do this myself; I'd just leave it to the qualified mechanic, but that's me. Normal disclaimers apply

Good luck, and let me know how it turns out.

Could be a vacuum leak but there are only about 8 vacuum hoses under the hood so it should not be to hard to find, however if you spray to much quick start the leak will pick it up even if its on the other side of the hood this can be confusing to find. The problem could also be that you have a hose clamp loose on your throttle body or air box and you may want to check the probe going into the side of the filter hosing to see if the gasket is on it.

vaccum lines look good, no apparent leaks.
I'm taking the CAI off this weekend and getting the K&N filter cleaned. i'll look for loose clamps, hoses... just about anything that will get this problem fixed.
thanks for the help guys