E92 M3, Squeal noise on cold start, opinions?

[E92Adan]

I have an ‘08 E92, and recently it’s discovered a weird squealing sound out of no where, quick backstory… I dropped my car off for an oil change, no issues at all, shop said a check engine light came on (never had one before), they pointed to the alternator because it wasn’t giving the right voltage to the “BSD CAN” , so went ahead and replaced that that…. They also noted a belt squeal on cold start and pointed to the Drive belt, so they replaced that as well (total was $1,400)…. I picked the car up, running fine. Next morning I turned the car on and the squeal noise can be heard for a few seconds, then they are now saying that it is the tensioners and are wanting to replace these parts.

Drive belt tensioner shock $162
Drive Belt tensioner pulley $210
A/C Belt Tensioner $148

Totaling about $960 with labor and parts.
Do you guys think I should go ahead and pay for it to be done? Easy DIY if I decide to replace these items myself? Or has anybody encounter this odd noise and ended up fixing it. Thanks

Link to the video of my car - https://youtube.com/shorts/rq50Jvgk4...hvN_kMDhG4nseQ

[panda-R]

How often do you drive it? Is it a few days between each drive? How long are the drives?

My 08 does this too and I think it's the alternator working hard after the battery has gone down a bit. It's not my daily driver and I don't drive it for long trips.

Try putting it on a tender every night and see what happens after it's fully charged.

[E92Adan]

Originally Posted by panda-R

How often do you drive it? Is it a few days between each drive? How long are the drives?

My 08 does this too and I think it's the alternator working hard after the battery has gone down a bit. It's not my daily driver and I don't drive it for long trips.

Try putting it on a tender every night and see what happens after it's fully charged.

I drive it every day, always on cold starts this started happening. It’s not the alternator because the shop replaced it for me, has to be something with the belt/pulley system, but I don’t see a reason why the A/C tensioner has to get replaced if the fluid is not leaking out of it.

[spammysammich]

Don’t pay hundreds for those stupid tensioner arms and pulleys. Just buy the pullies from fcpeuro and check out their YouTube and Instagram for other money saving tips.

[RocketyMan]

Originally Posted by spammysammich

Don’t pay hundreds for those stupid tensioner arms and pulleys. Just buy the pullies from fcpeuro and check out their YouTube and Instagram for other money saving tips.

This is exactly what I did!


Just buy the pulleys individually. I ended up only needing one when I checked mine. Also, I ended up buying the Continental Elite belts for supposedly quieter operation. Save yourself some coin!

[E92Adan]

Originally Posted by RocketyMan

This is exactly what I did!


Just buy the pulleys individually. I ended up only needing one when I checked mine. Also, I ended up buying the Continental Elite belts for supposedly quieter operation. Save yourself some coin!

I mean is it an easy DIY? I’m putting it away for the winter so I’m not too big in a rush

[amrazM]

Very easy diy, just pull off the air intake snout to the plenum and you have a fair bit of space to work with.

[RocketyMan]

Originally Posted by E92Adan

I mean is it an easy DIY? I’m putting it away for the winter so I’m not too big in a rush

Extremely easy for someone competent with tools.

Here's a very resourceful post someone made a while back since it can be hard to "search" on this forum...


https://www.m3post.com/forums/showth...1162212&page=4