Replacement alternator for E53 4.8is
 

I have replaced the alternator of my E53 4.8is a few weeks ago and it is whistling quite loud.
Additionally, the new one is regularly causing DME error code 2E95 (communication to alternator lost).

Has anybody here already replaced the alternator and managed to get an alternator which is not whistling and not causing DME error code 2E95?

Rebuilt? The ecu is very finicky with aftermarket regulators found in many rebuilt alternators. I would only replace with an oem unit or at a minimum, oem regulator. I would check the belt to ensure it is routed correctly. Flat side on smooth pulley, ribbed side on ribbed pulley. It can be routed differently.

It was sold as new, but I did not buy it from BMW (price at BMW is about 900 euros)

I have already renewed belt, pulleys and vibration absorber. It is definitely the alternator which is causing that sound.

If somebody has changed the alternator and does neither get a whistling sound nor the 2E95 error, please let me know which alternator you have bought

Not sure if the 4.4 and the 4.8 use the same water cooled alternator, but I put a NAPA alternator in a month ago and it’s working well. Only cost $400 US. ONLY! Haha, wife’s Honda needed a $65 alternator!
Good luck, it was not easy.
Doug


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I think 4.4 and 4.8 use the same alternator. Bought mine way back in 2011 for $353 and no issues whatsoever. Bought it from alternatorpros.com but I think the company was bought by starterpros.com? Not sure about that. Shipping was free at that time. You may consider buying from fcpeuro.com as they have lifetime replacement warranty.

Yes, if yours already has the N62 engine, the alternator is the same.

Did you check if these were causing errors in the engine ECU?

No alternator ECU errors from day one to-date.

This is what I bought for my N62 4.4:
2005 BMW X5 4.4L Alternator
180 Amp Valeo Unit N62

Great! Was it new or rebuilt?

I will make a video of the alternator area later doing:
1) Idle
2) on the throttle until about 2000-2500rpm
3) off the throttle

When going off the throttle, the alternator whistling is probably the most dominant sound.
Maybe you can also take a video when you have some time, so we can compare the alternator sound.

It was brand new. I have confirmed that starterpros.com is the former alternatorpros.com. I looked up my lifetime warranty at starterpros.com I had purchased ($15) from alternatorpros.com and my details popped up :D.

Here's the alternator I had bought:
https://www.starterpros.com/PartDeta...29359N&SRC=ORG#

New replacement is the whistling one?


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