Chirping blower fan

[Jay 535i]

My blower fan makes an intermittent chirping noise -- that's the only way I can describe it. It sounds like a flock of sparrows. It can happen at any blower speed, and it comes and goes, seemingly unrelated to road speed, blower speed or temperature.

It sounds like a little friction where there shouldn't be, somewhere inside the dashboard.

I can hear it equally clearly from inside the cabin or when standing outside next to the intake vents at the base of the windscreen.

What's the best way to solve the problem?

[shogun]

Have to disassemble it and see what's the point. Not so easy to do.
http://www.nmia.com/~dgnrg/page_2.htm

[ryan roopnarine]

the brushes are likely dying. the page shogun pointed you to will show you how to change the brushes, if you are mechanically inclined, and the motor/commutator are in good enough shape to reuse.

[Springfield1952]

I have the same issue on the Touring, at the high speed it sounds to me like a dry bearing. It is a little worse in the summer when I try to use the A/C. One of my earlier BMW's had the same symptoms but I could see the fan and I ran some oil down a coat hanger to the bearing. Fixed it right up.

Curt.

[Jay 535i]

One of my earlier BMW's had the same symptoms but I could see the fan and I ran some oil down a coat hanger to the bearing. Fixed it right up.

I was thinking of a fix along those lines.

At times it works perfectly. I suspect a bearing or some such rather than the motor.

[ryan roopnarine]

I was thinking of a fix along those lines.

At times it works perfectly. I suspect a bearing or some such rather than the motor.

i had the same problem too, one day, it sounded like the radio was squealing for about 15 seconds, and would do this (with a shorter duration) every now and then. about 6 months later, the motor picked up a wee bit of a hum. within two weeks, it was dead. the bearing remained fine through all of this. i'd politely suggest this. if the car is a daily driver, and you use the HVAC all of the time, (and you intend/know how to change brushes if/when it dies), i'd pull it now and see what the cause is. if you are going to just chuck a new unit in there when it dies, just leave it alone. its about striking a balance between wear and time if you are going to replace the brushes. if you leave it too long, you will kill the commutator, and be forced to get a new unit instead of reusing the old one.

[pyro]

mine makes a screeching noise on 3 and 4...

[peks]

my bearings were shot. chirped for a while, screamed for a while, then stopped altogether. then i called rigmaster

[Jay 535i]

Granted I don't know as much about this stuff as many of you, but I really get the feeling that a strategically placed drop of oil would do the trick. I just need some guidance on where that drop ought to go, and how to get it there.

[Gene in NC]

Come on, guys. Pull the sucker out. It's easy. Had the e30 in and out several times. Do it now as a service item. They all go to squeal over time. Brushes may go bad but our experience is that the bushes, as they wear, apparently vibrate or squeal. A rumble needs lube as much as a squeal.

The e28 is a real b---- with a heater blower like e34 plus another burried in the console for the ac. Very expensive job.

My wizard recommended, and I used and highly recommend, Wurth HHS 2000. Lubricant in a spray can is, "Resistant to high pressures and with high adhesive strength. Penetrates into tightest areas easily. Sets into a high temperature grease."

Use sparingly to avoid greasing the commutator.

Had to go to Wurth online and buy two cans at something north of $10 each. Wish every dollar I've spent gave such outstanding results. One can may last a lifetime but the stuff is the real deal with lots of other apps. When it reached through the grills to the bushes in the e28 AC blower I was ahead by more than 30 to 1 and counting.

The e30 bushing was so worn on the pass side that the magnetics would stall the motor. If the bushes had been lubed it might have gone 500k instead of 250k.