Hi folks

When I start my M3 from cold I can hear a bit of a strange whirring type noise coming from the fan area at the front of the car (clutch driven arent they?)

Anyway, if I leave the car running for say 2 or 3 minutes then I can hear the fan kick in (Loudly!) and the dodgy noise stops!!

I have not monitored it after this but the noise is not there after journeys or whatever. Just seems to be from before the fan kicks in...

My question...is this normal? (or is my fan clutch on the way out?) and I would like to know if these fans ARE supposed to be constant?? as in maintain a steady temp all the time and not just cut in in traffic like other car fans do. Or, should they cut in and out depending on temperature (which never moves from the middle of the gauge on my car)

Thanks in advance guys  

The fan on the e36 m3 is a viscous fan it is driven all the time even from cold. when the engine heats up  the liquid in the vicous fan clutch heats and expands and the fan speed increases. when the car is in traffic the fan rotates faster. and after a long fast run on a motor way it runs slower.  The fan is engine driven by the altenator belt. it the viscous fan hub/ clutch that regulates the fans speed according to the engines temprature. Even on a freezing cold morning on cold start the fan will still be rotating round. 

The problem I think you have is the auxillary air pump. this is at the bottom front drivers side of the engine. this is driven by belt of the main crank pulley. when engine is cold the air pump takes hot air from around the exhaust manifold and supplies it to the inlet manifold, this helps with emissions. the pump only operates for a short time  until water temp has reached over 26 oC  This pump is notorius for making all sorts of clattering whirring and strange noises.  The pulley that drives it always rotates but the pump itself has an electromagnetic clutch which is switched on and off by the engine ECU.  If the funny sound only happens for a couple of minutes  while the engine warms up then I would forget about it its nothing to worry about. These units are not cheap and only realy run for about two minuets on cold start up and then thats it, they do bugger all after that.

this happened to mine, the dual magnetic clutch seized and starting making a horendous noise :(

bmw wanted something like £240 + vat for the pump alone or £140 for the clutch,

i picked up an evo pump from FAB Direct for £125 next day delivery to scotland as well

Thanks for the info guys

It seems the consensus is that it could well be the auxillary air pump that is making the strange noise for say the first two minutes of startup.....and it makes a lot of sense.

Is it not something I should look into fixing then? or shall I just keep an eye on it for a few weeks and see if it develops instead of racing out and buying a new one!

Torch Str8 6
was the problem that you had simliar sounding. my noise is a kind of squealing/whirring type of noise (very hard to describe really!!)...and when your magnetic clutch seized did your car make the noise ALL the time or just on start up? and before it seized did you have any warning noises or signs or anything??

Thanks in advance folks

Also Torch Str8 6

who are Fab direct and are they a good BMW parts supplier?? can you give me any contact details if so

Thanks

If you need an air pump, I have one from my Evo engine. I have no idea if it's good or bad as I removed it before fitting the engine, but it's yours for the price of postage

Cheers,

Ian.

That would be superb Ian. Really Appreciated mate.

Is the air pump complete with the magnetic clutch bit attached to it?? and is there any particluar reason you took it off the engine before you fitted the lump or??

If you could PM me with you address details then I will get a cheque in the post for you mate to cover the postage!! (unless youve got another idea of course?)

Thanks Again

it used to make a funny noise for a few mins on startup then would go away, then all of a sudden without warning it was like a metallic grinding noise and i could actually see sparks coming from the clutch

http://www.fabdirect.com/ - http://www.fabdirect.com/

its the first time ive dealt with FAB but they were excellent and very proficient, would highly recommend them

andrewc wrote: That would be superb Ian. Really Appreciated mate. Is the air pump complete with the magnetic clutch bit attached to it?? and is there any particluar reason you took it off the engine before you fitted the lump or?? If you could PM me with you address details then I will get a cheque in the post for you mate to cover the postage!! (unless youve got another idea of course?) Thanks Again

Hi Andrew,

Yes, the air pump is complete with the clutch still attached.

I transplanted the engine into an E30 325i chassis, and did not want/need all the emissions equipment on the engine, so it was removed along with all the pipework that goes with it.

I'll send a PM with my details.

Cheers,

Ian.