Whistling sound help....

[scjshaylen]

During normal acceleration there is a whistling sound from the front of the car, and while maintaining low speeds. Can't hear the noise over the wind if traveling over 35 mph. Gotta have the windows down to hear it. During hard acceleration the sound goes away. I know it's hard to say just from some one explaining, but it's worth a shot if I can figure it out myself, or with a little help from around here!

I have a 99' 528i with 88,000 miles. Any help is appreciated.

[GuapOh]

Mine does the exact same thing. It started when I installed an aftermarket CAI so I figured it was an intake whistle from all the extra air being sucked into the MAF or some other portion of the intake. Do you have an aftermarket intake?

Mine is consistent at 2300-2700 rpms, below 40 mph. When I go WOT it goes away or if I flick the gas it goes away momentarily, then returns. Annoying as hell.

[chafik11]

i have the same problem, i started to hear it after i instaled CAI, and i have 99 528i with 84k, could be an air leak??

[nightkrawler]

sure you guys aren't just hearing the mechanical fan? now that its getting hot outside the cars are running hotter so its more likely for the fan to lock up. it's a viscous clutch which as it gets hotter there are two plates inside the clutch that push together, when this happens the clutch locks causing the fan to spin full speed. mine gets nosiy as hell when it gets real hot, sounds like sc whine almost.

[chafik11]

I know what you mean, besides the sound of the fan when it's hot , this sound is coming from the throttel body.

[chicagocubs26]

I have reviewed Roadfly posts and many attribute this whistle to the cold air intake, especially Dinan, which I have on my 99 528iT. Starts off like a high whistle, then goes to a lower tone, then either disappears or is drowned out by the motor as it revs up. If you don't have any loss in performance and this has been a constant sound that hasn't just appeared lately (unless you have just installed a new CAI) this may very well be the culprit.

Good luck

Craig

[Mohamed 525i]

http://www.bmwtips.com/tipsntricks/tips_pages/liftpads.htm

this might help

[Litespeeds]

I hear this whirling sound from the engine compartment and my 01' 540it is all stock. From the descriptions posted above, it probably is the fan. I haven't had time to take it in to have it checked out. If it is the fan, is there anything that we can do to get it quieter or silent if possible?

[scjshaylen]

I thought this post was gonna go unanswered! I'm not on here everyday.

I've had the car for about two months now, and I'm pretty sure it's all stock. I'll have to go verify that though. Thanks for the replies and I'll post anything I find out.

[nightkrawler]

no, nothing you can do to quiet the mech fan than possibly buy a new clutch which is very expensive and most likley going to sound the same.