E34 540i6 Engine wheeze

[540Hokkenheim]

I cant be the only one who experiences this, but lately when I rev my engine at idle, or when I accelerate it sounds what I would describe as a "wheeze".

The sound is reminiscent of a giant turbine spinning under my hood. I have noticed this anomaly off and on since I bought the car. Any ideas? It is getting on my nerves.

I will try and get a audio/video clip.

[xatlas0]

I cant be the only one who experiences this, but lately when I rev my engine at idle, or when I accelerate it sounds what I would describe as a "wheeze".

The sound is reminiscent of a giant turbine spinning under my hood. I have noticed this anomaly off and on since I bought the car. Any ideas? It is getting on my nerves.

I will try and get a audio/video clip.

Could be your AC compressor clutch or the compressor itself.

[dgeiger540i]

could be the aux fan spiinning?

[540Hokkenheim]

Yah, it's tough to pin down. It may coincide with a stange fan that starts up frmo time to time that can be heard coming from the passenger side under the glovebox. It's an annoying fan that just comes on from time to time. So it may be the aux fan kicking in. This just started about 2 months ago; possibly in lieu of the hotter weather.

[VentoGT]

May be the Fan clutch stuck on--my M5 sounded like a Mack Truck when I first got it because the clutch never disengaged, so the fan would spin with the engine speed at all times--the fan whine was louder than the S38 motor...

[hecubus]

I just had my waterpump/fan/fan clutch replaced and it does the same thing...I'm hoping its just the 'newness' of the fan clutch and will loosen upo soon. Does sound a bit like a turbo spinning up though

[VentoGT]

Check to make sure the fan clutch isn't a Behr part--I don't know what the e39 uses/if it is the same as the e34, but there have been several people [including myself] in the last few months with bad Behr clutches right out of the box. Get the Sachs part if you have a choice, and have the fan clutch checked out.

The fan staying on is LOUD, I mean louder than the engine...not necessarily high pitched like a turbo but like you are next to an accelerating dumptruck.

[Goat128]

wow thats a weird one.. guess you read the forums long enough you hear everything. sounds like maybe a belt, pully, or belt accessory.

[540Hokkenheim]

May be the Fan clutch stuck on--my M5 sounded like a Mack Truck when I first got it because the clutch never disengaged, so the fan would spin with the engine speed at all times--the fan whine was louder than the S38 motor...

Yah, this could be too.

[Grim Reaper]

Yah, this could be too.

+1

on the fan clutch going south

[azvin]

Hope you pin it down. My car has the exact same problem. It's embarassing when I'm driving slowly around parking lots and my cars whining like its fan powered. :(

[540Hokkenheim]

Hope you pin it down. My car has the exact same problem. It's embarassing when I'm driving slowly around parking lots and my cars whining like its fan powered. :(

That is pretty much what prompted this post.

I am almost sure that it is the fan clutch spinning at the same speed as the engine. This makes sense to me. I am not versed in the exact workings of this mechanism, but it seems logical to me. Looks as though I will have to take it to the shop unless anyone has any tips I can work with.

After searching around I was unable to find any tutorials on a fix for this. I will attempt this fix myself if I knew what I was doing.

[xatlas0]

That is pretty much what prompted this post.

I am almost sure that it is the fan clutch spinning at the same speed as the engine. This makes sense to me. I am not versed in the exact workings of this mechanism, but it seems logical to me. Looks as though I will have to take it to the shop unless anyone has any tips I can work with.

After searching around I was unable to find any tutorials on a fix for this. I will attempt this fix myself if I knew what I was doing.

A quick way to see if the fan clutch is working is to try and spin the fan when the car is cold and off. (Off is very important in case it is stuck, unless you like not having all your digits.) You should be able to spin it with little to no force. If it will not move, then you know the fan clutch is bad. Replacement isn't all that bad, just a bit cramped. All you have to do is unbolt the fan, unbolt the old clutch, bolt up the new one, (make sure it is facing the right direction first) then bolt the fan back up.

Conversely, if the car is hot and you can still spin the fan, the clutch is stuck off, a rather rare occurance.

[540Hokkenheim]

Thanks man, I'll take a crack at. I would love to have a reference manual that BMW mechanics use/learn from so that I could do all the work on my car. Is such an item available? Anyone know where to get one?

I have a Bentley manual, but I need something much more verbose. I am sure that there would be ALOT of interst in an item like this.

[TheIronGiant]

While this may or may not address your "wheezing" issue...I have to disagree with the other posters about the fan clutch. I experienced this first hand while replacing my engine's thermostat.

In my experience, the fan will be stiff when the clutch fluid is cold and require much force to move. But as the clutch fluid heats up it loosens and the fan spins freely. In fact, if you let the car warm up for 5 minutes, you can actually stop the fan safely with your hands. When you let go, the viscous clutch flowing so freely that the fan will not "catch up" to engine speed for at least 15 seconds.

Bentley manual confirms this behavior.