Quote:
Originally Posted by TDF9
My 2006 325i 6MT makes a low droning noise that rises and falls with engine speed, and completely disappears when I turn off the HVAC system (by lowering the fan speed to zero, so the whole system goes off).
The HVAC fan also occasionally squeaks, so it's on my list to get to it under the dash and lubricate it. But I'm inclined to think this whining / droning noise is an entirely separate issue, as it's not a function of fan speed but, again, engine speed.
It's subtle but quite noticeable and irritating. Each time I pull away from a traffic light I hear the droning noise rise in pitch as the revs rise.
If the noise were coming out of the stereo system I'd think it was some form of electrical interference from the engine ignition system, or inadequate shielding. But alas, no connection to the stereo system being on - noise persists so long as HVAC is on (and regardless of what speed the fan is set to).
Anyone ever experience this? I appreciate any ideas!
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Sounds as though it could be one of two things: 1)the HVAC blower motor is going out or 2)the bearings in the pulley of the A/C compressor are bad.
You may know this already, but in case you were not aware, there is a safety recall on the wiring in conjunction with the blower motor. See this link for recall details:
https://static.nhtsa.gov/odi/rcl/201...7V676-3259.pdf
Part number (blower motor):
https://www.fcpeuro.com/products/bmw...cm-64119227670
[FCPeuro has lifetime parts replacement, which is the best in the market]
See this link for blower motor replacement instructions:
https://www.pelicanparts.com/BMW/tec..._Replacing.htm
For the second issue:
There is a thread from a Canadian guy who replaced the pulley/bearings in the A/C compressor as opposed to replacing the entire unit; IIRC he had good results.
I will do a search and post a link here if I locate it.