# The five-second shriek



## Philm35 (Aug 19, 2010)

My D has been making an annoying noise, after the car has been parked out in the hot sun for several hours. Within about 30 seconds of starting, a loud shriek emanates from the engine compartment. It lasts about 5-10 seconds, goes away and doesn't come back until the next time it's been sitting for hours under the hot sun.

It sounds a bit like a noisy alternator bearing or something similar. Doesn't quite sound like a belt slipping. The noise appears at idle or very low RPM, with or without the car moving.

Coincidentally (or not), the noise first appeared right after the dealer had the car for the latest recall campaign.

Any thoughts? It's going back to the dealership this week... My fear is it won't make the noise for them.


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## KeithS (Dec 30, 2001)

Common issue, it's the AC belt. BMW did not use a tensioner for the AC belt on our cars, it's essentially a very large rubber band stretched between the engine and AC compressor. I think they have one that's a tad smaller to make it tight enough not to slip.


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## 335dFan (Nov 8, 2012)

KeithS said:


> Common issue, it's the AC belt. BMW did not use a tensioner for the AC belt on our cars, it's essentially a very large rubber band stretched between the engine and AC compressor. I think they have one that's a tad smaller to make it tight enough not to slip.


SI B64 08 11 - AC Compressor Squeal.pdf


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## Philm35 (Aug 19, 2010)

Thanks, guys! 

--Phil


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## Axel61 (Mar 10, 2011)

yep AC belt get it done pronto!! before it screws something else!!


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## Flyingman (Sep 13, 2009)

That was probably one of the most annoying and embarassing noises I have heard.:yikes:

Totally NOT cool.

Haven't heard a peep since mine was changed some 2 or more years ago.:thumbup:


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## Philm35 (Aug 19, 2010)

Took it to the dealership last thursday. I played a recording of the noise I made on my iPhone for the service advisor. It wouldn't make the noise for them. Same on Friday. They won't do any repairs until they hear the noise themselves. 

Sigh.


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## stoked335d (Jan 4, 2010)

I thought there was a recall on that belt.


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## Axel61 (Mar 10, 2011)

Philm video it and show it to the SA thats what I did here in Puerto Rico and they fix it after that, video will convince them


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## boooomer (Apr 23, 2010)

Philm35 said:


> Took it to the dealership last thursday. I played a recording of the noise I made on my iPhone for the service advisor. It wouldn't make the noise for them. Same on Friday. They won't do any repairs until they hear the noise themselves.
> 
> Sigh.


FWIW My dealer replaced the belt without having to duplicate the problem. Good thing as it only made the squeal on first starting up after sitting at least overnight and the ambient temp in the upper 80's. It only squealed when the AC was on. Difficult to duplicate without having to keep the car overnight.
The repair order referenced "SIB 64 08 11"
& "DEFECT CODE 11 28 03 39 00". They also replaced the AC compressor - though I thought that the AC was ok.


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## BB_cuda (Nov 8, 2011)

My car has never done this. New to my work parking lot is another 335D. The person started driving it into work about a week ago. Yesterday, when i was walking out to the lot a heard a loud squeeling sound. I saw a car from far away coming towards me with same squeel getting louder and louder . It was the other 335D. Lady says they bought it in October 2011 but i don't know its production date.


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## KeithS (Dec 30, 2001)

Mine only does this when it's very hot outside, and the car has been closed up and is extremely hot inside. Then when you start the AC the compressor it's under an extreme and abnormal load for the first minute or 2. I found if you just let the car idle for a minute or 2 before driving off, you can be saved from the embarrassment.

The fix is to install the belt from a different (the wrong) BMW model which is just a little shorter and tighter so it will not slip. There is a tech bulletin on this. If the dealer replaces with the belt as indicated in the parts list, nothing will be changed and it will still squeal.


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## taibanl (Oct 3, 2010)

To reproduce

Ac off
Park car at least 1hr, pref 3hrs in 80F or above

Start car,
Before allowing car to cool: ac on

She'll squeal like a banshee after 15 seconds. 


Sent from BimmerApp mobile app


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