XC70 D5 growling engine noise
 

Has anyone ever encountered this noise:
https://youtube.com/shorts/6L34jGMYz9c?feature=share
It’s coming from the alternator/timing belt area. Kind of like a loud growling when revving.

I suspect the alternator bearings. The only other symptom is a whistle at high speeds.

I would take the auxiliary belt off and start the car to see what noise is still present.

If the noise has gone, ideal opportunity to check alternator and air con pulleys as well as tensioners etc.

Thanks, good shout. Didn’t think of taking the belt off.

From memory it's a 60 torx that fits tensioner and it has a BLOODY STRONG SPRING so be careful.:teeth_smile:

If you could get someone to steadily film just the pulley area in good daylight, with the engine running, a bit of light revving then the engine switch off, that would be a help.

Also what mileage? This should be compulsory for any query.
Because the noise stays briefly after engine switch off, my guess is the alternator clutch pulley.

Thanks cheshired5, I’ll do that tomorrow and update the video. It’s a 2013 D5 awd with 98k miles, full dealer service history. It had the aux belt replaced two services ago, not sure about the tensioner as it was a service plan.

Sounds a bit like something rubbing the casing, belt is not shredding is it.?

Had the same issue. It was a belt vibrating. I changed the belt and all was better

So, did more filming...and investigating.
Seems the noise is coming from inside the alternator.
I was hoping to get away with a new clutch pulley not a whole new alternator :(

https://youtu.be/R4NOIKOEGAw

https://youtube.com/shorts/kHio9NlkcAc?feature=share

The clutch on the pulley seems to be ok as the alternator runs on fine after engine switch off.
Sounds like one or more worn alternator bearings which are cheap and replaceable but not necessarily easy depending on your experience or tool collection.

Odd for such low mileage.