02 Suburban, has a whistling noise at 1000 rpm. Kind of like blowing across the top of an empty bottle. Its not high pitched, not a whine or a squeal and it happens ONLY at 1000rpms....it happens whether your driving along at 1000, rev and hold at 1000 in park, or even as you accelerate it will whistle as it passes 1000 rpms and then stops.....doesnt do it any other time. I'm at a loss, so any advice would be welcome. Thanks, Ron

 

hey ron,

in this situation, i would almost assuredly (sp) that this has something to do with your air intake. As air, is one of the only things, that can usually cause a "whistle" i would first do this.

check all your clamps on your intake system, see if any are lose, and make sure they are all secured correctly, no holes, leaks ect.....

then i would pull your air filter, and rev your truck to 1000 rpm, see if the whistle goes away, i would bet you might just have a dirty air filter, or a lose connection in your intake system. sounds like what that is to me.

if that doesnt end it, u might pull your intake off and take a look at ur Throttle body, make sure everything looks right on the inside of there. Nothing stuck in the flap, anything of that sort, and if that doesnt stop it, post it, so we can help further

hope this fixes your problem
jared

ps. i wouldnt X out manifolds, but exhaust leaks are usually "ticks" not whistles. a whistle tells me intake.

 

also check your fan, i just thought of that too, your clutch fan can make that whistle on the bottle noise. see if everything is working fine with your fan, and theres nothing caught in there, or damage, see if your radiator is clogged at all, do you have cooling issues???

 

No cooling issues, but I will definitly check all the connections like you suggested. It sounds like its coming from somewhere near the middle/front, could be something to do with the fan or throttle body I suppose....I'll check it out and let everyone know what I can find. Thanks, Ron

 

What are your mods? Is it totally stock, or do you have an aftermarket CAI, exhaust, etc? It may be "characteristic", unless it just started happening. Have you made any recent changes that may account for the noise?