funny sound when Fan is one.

[BatKing]

Hi,

My Final stage Resistor is bad and the new one should be my home tomorrow. However there is something strange related to the fan.

before my FSR went completely bad, I heard something when the Fan is turned ON. the sound like some small smooth electric motor. something like "WOooooo.... WOooooooo" in pulse. This is not happening all the time.

Now since my FSR is bad and the fan won't be off even the car is off. so I took the Fan Fuse out and waiting my online ordered FSR to come (Local Dealer wants $137.xx + tax ). and I didn't hear the funny sound for last 2 days when I was driving. the Fan still turned on, but there is only outside fresh air coming when at freeway speed.

Then today I hear the sound again, and since it is the 1st time I hear the sound when there is no Fan Action, so I can hear it pretty clear and trace the source of the sound. It is in the engine bay. I don't know where exactly it is, but it is on the driver side and very close to the Power Steering oil carrier/reservoir.

My question is, if this sound is related to a bad FSR? if I turn off the fan control, the sound will be gone.

Thanks.

[Weasel]

Could it be the tensioner pulleys getting noisy?

[BatKing]

hum.... I think my tensioner pulley was replaced under warranty about 6 months ago. but I need to double check it.

so it is related to the Fan? turning on the fan triggers the Tensioner pulley's sound?

[Weasel]

Shouldn't be connected with the ac blower fan... but since you say you hear it without the fan on now and from the engine bay near the steering resevoir it might not be related to the fan. It may be the idler pulley if they changed the tensioner pulley, but could be something else. You likely need someone who can hear it to make the prognosis.

[01 BMW_X5]

Run the engine when cold for a minute with belt off and listen.
Try listening with a "mechanic's stethoscope"(Harbor Freight - $1.99).
Good tool to have in your toolbox.

[EKS PYB]

I actually hear a whining/squeaking noice as well whenever my car cools down after a long drive in traffic and the fan stays on after the car is off. Is that the tensioner as well?

Can tensioners be lubricated or does it have to be replaced? or just tightened?

[BatKing]

Originally Posted by weasel56

Shouldn't be connected with the ac blower fan... but since you say you hear it without the fan on now and from the engine bay near the steering resevoir it might not be related to the fan. It may be the idler pulley if they changed the tensioner pulley, but could be something else. You likely need someone who can hear it to make the prognosis.

I mean if it is not related to the ac blower fan it self, then it has to be something related... at least to the AC Blower Fan On/Off control.

I tried it with more experiment. I can turn the Key to ON position without start the engine, then turn on the AC Blower FAN control (FAN won't be on as the fuse are out). at this point since the Engine is off, FAN is Off (with the control turn to ON but fuse off), I can hear the sound clearly from the Power Steering Reservior area. Turn the Fan control to completely off, the sound will be gone. is this related to electronic parts?

So with the AC Fan control turn on, the sound will be there (sometimes, not everytime) and with the AC FAN control turn off the sound will be gone (everytime. 100% works).

I will try to record the sound and post it on youtube to see if that helps.

[01 BMW_X5]

Originally Posted by EKS PYB

fan stays on after the car is off. Is that the tensioner as well?

Can tensioners be lubricated or does it have to be replaced? or just tightened?

Car off - tensioner >> not spinning
Tensioner has to be replaced.

[EKS PYB]

AYAYAY ! ! !

Yeah, I'm due for INSPEC II and that was one of the things I was thinking of doing. Now, do I need to replace both tensioners...I believe there's two correct and while I'm at it might as well replace the belt and since i'm doing the belt might as well do the water pump...CORRECT?


OOOPS, sorry...I hope i'm not hijacking the thread since we're talking about fan noises and all...my apologies

[Weasel]

Originally Posted by BatKing

I mean if it is not related to the ac blower fan it self, then it has to be something related... at least to the AC Blower Fan On/Off control.

I tried it with more experiment. I can turn the Key to ON position without start the engine, then turn on the AC Blower FAN control (FAN won't be on as the fuse are out). at this point since the Engine is off, FAN is Off (with the control turn to ON but fuse off), I can hear the sound clearly from the Power Steering Reservior area. Turn the Fan control to completely off, the sound will be gone. is this related to electronic parts?

So with the AC Fan control turn on, the sound will be there (sometimes, not everytime) and with the AC FAN control turn off the sound will be gone (everytime. 100% works).

I will try to record the sound and post it on youtube to see if that helps.

If it happens with the engine off and the blower not turning, and is under the hood near the power steering resevoir... It could be the aux water pump or heater control valves, both in that general area. When it is doing the noise in these conditions look for #13 and #1 from this link.

http://www.realoem.com/bmw/showparts...64&hg=64&fg=18