Remove the serpentine belt and see if the noise is still there. If it's gone than one of the pulley or bearing that is being driven by the belt is the cause for the noise.

Ok, I will try these things this coming week. I have a week off of work, so I should have some time. I appreciate all the help, and I'll definitely update y'all when I start tearing stuff up.

Thanks!

when I replaced my fan clutch I noticed it was much louder on startup then before. It has taken some time (months) for it to quiet down. I attribute it to the new clutch being much stiffer then the new one. As it has broken in, it has quieted down.

Interesting...this started months AFTER I installed the new fan clutch though. It doesn't seem to be doing any damage(except to my ear drums) so it's very intriguing. I've promised my wife I would finish laying hardwood upstairs next week, but hopefully I'll be able to dig into this as well.

Ok, so I just left for lunch and when I cranked my car, it made that sound again. I was able to check, and the aux fan wasn't even spinning. Bad motor? When I turn the AC on, the fan doesn't come on either.

After doing too much research, I've learned that it's called the "pusher fan." This is the fan that isn't spinning.

Upallnight, I have been reading up on your previous posts about you replacing your pusher fan. I think that's the route I should take, but I am still confused about all the noise being produced from under my hood when I crank it. Did your X make the same racket?!

Before buying and installing a new aux fan, you should verify that it is the fan. There's a 50 amps fuse behind the glove box, if that is blown you can bet your sweet dollars that the fan is also bad.

If you have access to BMW software you can see if there's a fault code for the fan. The DME commands the fan to spin and when the fan is freewheeling it sends back voltage to the DME. The DME sees this voltage and knows that the fan is O.K.. If the DME doesn't see this voltage the DME knows that the fan is not turning.

No my X does not make any rackets when I crank it.

Noise is the secondary air pump, pretty sure now from your description.

Number 1 in this diagram, Behind and below the passenger side headlight.

http://www.realoem.com/bmw/diagrams/h/o/192.png