2010 BMW M3 S65 V8 noise sound please help

[bmwfanhere]

Hello,

Can someone please help me troubleshoot the noise coming out of my car? I looked up on youtube so many vids and I don't believe it's rod bearing issue.

Is it serpentine belt or one of those pulleys?

Thanks so much in advance!

here is the video of the noise
https://www.youtube.com/shorts/-ga_LRCn0mk

[kolosy]

the little jingling sound? probably a pulley or idler.

[bmwfanhere]

Originally Posted by kolosy

the little jingling sound? probably a pulley or idler.

yes, thanks for describing it. it does sound like jingle bell

[RocketyMan]

I agree. I think it's a pulley of some sort on the accessory belt or something along those lines. It's fairly easy to take off plenum and disconnect the belts and then spin the pulleys by hand--including things like the water pump. You should be very able to tell a bad pulley.

[bmwfanhere]

thank you very much for your help.

i tried to spin with my hand but couldn't tell which one gone bad

the original belts dated 2009 are in excellent shape, the idler appeared to have no issue with my hand spinning it

anyway i replaced belts and idler pulley but the same noise still there. i guess i have to replace the tensioner (more $ than the idler pulley)

[KawBoy]

Have one of these things; it helps a lot.

https://www.harborfreight.com/mechan...ope-63691.html

[bmwfanhere]

Originally Posted by KawBoy

Have one of these things; it helps a lot.

https://www.harborfreight.com/mechan...ope-63691.html

Thank you very much. I'm going to get myself a stethoscope and hope to pinpoint the noise, I don't want to spend the extra $ for both AC and radiator pulley and tensioner. (see pic, very pricey)

[walterty]

Hey you can source the pulleys on those tensioners and not have to buy the $200 part.
I can dig out some part#s if you want.

[spammysammich]

FCPEuro posted this to their instagram feed a while back.

[spammysammich]

If your tensioner is still in good shape that may be a good way to save some $$$

[kolosy]

Actually the M359 M3 series from a few weeks back go through this exact process.

[nick3753]

If just replacing the pulley on the tensioner, is it necessary to remove the tensioner from the block, or can the pulley be swapped while it is still attached?

[Scrippy]

Originally Posted by nick3753

If just replacing the pulley on the tensioner, is it necessary to remove the tensioner from the block, or can the pulley be swapped while it is still attached?

Removed from the block. It’s all one part. There are two tensioners as there are two belts. A complete refresh kits is like $800-$900 fyi. Kinda my opinion that if your in there just take care of the whole system but if on a budget just do whatever you can.

[nick3753]

Originally Posted by Scrippy

Removed from the block. It’s all one part. There are two tensioners as there are two belts. A complete refresh kits is like $800-$900 fyi. Kinda my opinion that if your in there just take care of the whole system but if on a budget just do whatever you can.

I get that, and that was the plan prior to my OFHG failing. I also believe (and will hopefully confirm this weekend) that my oil thermostat isn’t working so may need to replace the entire housing. And then of course, I sprung a diff leak and I’m fairly certain the U joint on the driveshaft is bad. That cold week really took a toll on my 170k car. A lot all at once (and still need to replace valve covers).

So…thinking of reducing the pain by just replacing the 3 pulleys, belts and water pump while I’m in there, as long as the tensioners aren’t seized up. All are original. Suspsension probably needs some love after all these pothole filled miles on Michigan roads. Ok, done whining. Enjoy your weekend.

[Scrippy]

This is exactly how my car acted a year and a half ago. Oil filter housing leak. Cleaned the oil off the block with simple green. Well that degreased my pulleys and all of them sounded like Chewbacca. Replaced oil filter housing gasket and all pulleys. Then my velocity joint on the driveshaft went bad. Had to replace that too. Kinda disappointing as I never use launch control.