E46Fan
11-19-2020, 06:14 PM
Ok, to start: 2005 330ci ZHP, 120k miles, 6 spd man
So here is the story, my car is running great, no dash lights of any kind. When warmed up, I have a subtle whining noise. Gets a little louder with higher rpm, but doesn't really track with rpm. Intake boots are in good shape. The belts and idler pulleys are all new. I can't quite seem to tell where the sound is coming from. One thought was the power steering pump, so I figured a good flush with new fluid plus replace the reservoir because it has a filter and the cap o-ring has failed. No change, still a slight whine when warmed up. I did freshen up the tranny fluid (manual) and diff fluid at 100K with Royal Purple.
I did some youtube searching and ran across this vid:
https://www.youtube.com/watch?v=72REiFhvNuE
I got my voltage meter out to do some testing. My altenator is pushing out about 14.5v and it drops to about 14.2 when lights and accessories are all on. When I switch from DC to check AC as described in the vid, I have 75mV AC. So, I'm not at 50mV, nor am I over 100mV.
The other oddity is my alternator does not have a cooling shroud on the back and thus no snorkel as I had on my 325 and as shown in real OEM. The PO maintenance records show no evidence the alternator was ever replaced (could be missing record). I neglected to look and see if it was Bosch or Valeo, or something else.
Thought I would tap into the collective wisdom here:
Is the information in the vid a valid diagnosis?
Am I looking in the wrong place?
Any other thoughts on where this noise may be coming from?
So here is the story, my car is running great, no dash lights of any kind. When warmed up, I have a subtle whining noise. Gets a little louder with higher rpm, but doesn't really track with rpm. Intake boots are in good shape. The belts and idler pulleys are all new. I can't quite seem to tell where the sound is coming from. One thought was the power steering pump, so I figured a good flush with new fluid plus replace the reservoir because it has a filter and the cap o-ring has failed. No change, still a slight whine when warmed up. I did freshen up the tranny fluid (manual) and diff fluid at 100K with Royal Purple.
I did some youtube searching and ran across this vid:
https://www.youtube.com/watch?v=72REiFhvNuE
I got my voltage meter out to do some testing. My altenator is pushing out about 14.5v and it drops to about 14.2 when lights and accessories are all on. When I switch from DC to check AC as described in the vid, I have 75mV AC. So, I'm not at 50mV, nor am I over 100mV.
The other oddity is my alternator does not have a cooling shroud on the back and thus no snorkel as I had on my 325 and as shown in real OEM. The PO maintenance records show no evidence the alternator was ever replaced (could be missing record). I neglected to look and see if it was Bosch or Valeo, or something else.
Thought I would tap into the collective wisdom here:
Is the information in the vid a valid diagnosis?
Am I looking in the wrong place?
Any other thoughts on where this noise may be coming from?