Brand New Belt chirping / squealing ???

myculito · 10-04-2017, 09:17 AM

So, I recently started this thread after my harmonic balancer failed:
http://www.e90post.com/forums/showthread.php?t=1425970. I put on the new accessory belt that I bought from ECS, but I re-used the AC belt

Although the repair was successful, I noticed that the belt (pretty sure it's the accessory belt is squeaking). On start up, there is a noticeable chirp that's less than a second.

But from time to time, the belts will audibly squeal for a couple of seconds, and then goes away. It's not all the time though.

In my research, it appears that ECS gave me the belt Contitech 6K X 2065. Looking at the BMW OEM number, the belt should be a Contitech 6K X 2063.

Can someone shed some light on this? Thoughts?

PerfectAce · 10-04-2017, 09:49 AM

I don't think the 2065mm belt is your problem. Not sure why there is a discrepancy, but the tensioner will take out the small amount of slack. I'm using the 2065mm belt and haven't heard a peep from it.

On the other hand, you say you re-used the A/C belt. It's a known issue that the original 830mm belt would occasionally squeal and BMW recommended that the belt be replaced with an 824mm. But if that old belt wasn't squealing before, why would it start now?

My first thought is that your A/C belt may not be properly seated on the A/C compressor pulley. When I installed mine, it had a tendency to slip toward the front by one groove. I had to take the belt off, line it back up, and when turning the crank use my other hand to push the belt toward the engine block to prevent it from slipping out.

If you're certain that the belt is properly seated in all six grooves, then I would say that you need to try putting the 824mm belt on.

335dsleeper · 10-04-2017, 09:59 AM

Stretch belts like the AC belt should never be reused.

Torqu3 · 10-04-2017, 11:07 AM

Quote:

Originally Posted by PerfectAce

I don't think the 2065mm belt is your problem. Not sure why there is a discrepancy, but the tensioner will take out the small amount of slack. I'm using the 2065mm belt and haven't heard a peep from it.

On the other hand, you say you re-used the A/C belt. It's a known issue that the original 830mm belt would occasionally squeal and BMW recommended that the belt be replaced with an 824mm. But if that old belt wasn't squealing before, why would it start now?

My first thought is that your A/C belt may not be properly seated on the A/C compressor pulley. When I installed mine, it had a tendency to slip toward the front by one groove. I had to take the belt off, line it back up, and when turning the crank use my other hand to push the belt toward the engine block to prevent it from slipping out.

If you're certain that the belt is properly seated in all six grooves, then I would say that you need to try putting the 824mm belt on.

I ran the AC for a day, and never had a squeal. Harmonic balancer failed. The day after I got the balancer replaced and started the AC, the squeal started. Replaced the belt and had no problems. It's definitely possible for the belt to squeal only after a HB replacement.

myculito · 10-04-2017, 01:50 PM

perhaps it is the AC belt then. But why would there be a recommendation for an 824mm AC belt, when the OEM version is 830mm?

myculito · 10-04-2017, 02:01 PM

Quote:

Originally Posted by 335dsleeper

Stretch belts like the AC belt should never be reused.

I don't disagree. However, I had such a hard time trying to get the new shorter 824mm AC belt on that I said screw it, and went back to the 830mm belt.

myculito · 10-04-2017, 02:02 PM

Quote:

Originally Posted by Torqu3

I ran the AC for a day, and never had a squeal. Harmonic balancer failed. The day after I got the balancer replaced and started the AC, the squeal started. Replaced the belt and had no problems. It's definitely possible for the belt to squeal only after a HB replacement.

Did you replace the AC belt with the OEM 830mm, or the aftermarket 824mm?

Torqu3 · 10-04-2017, 05:05 PM

Quote:

Originally Posted by myculito

Did you replace the AC belt with the OEM 830mm, or the aftermarket 824mm?

824mm. The OE 830mm belt squealed. There is a SIB for this. Use the shorter belt.

Torqu3 · 10-04-2017, 05:06 PM

Quote:

Originally Posted by myculito

perhaps it is the AC belt then. But why would there be a recommendation for an 824mm AC belt, when the OEM version is 830mm?

It's a service bulletin to fix a common problem.

OmahaDZL · 10-05-2017, 10:05 AM

Quote:

Originally Posted by myculito

I don't disagree. However, I had such a hard time trying to get the new shorter 824mm AC belt on that I said screw it, and went back to the 830mm belt.

I reused mine and have had zero problems...

myculito · 10-25-2017, 04:07 PM

Just a follow up to this:

I bought the official BMW install v-belt installation tool (part # 110330), similar to this listing: https://www.ebay.com/itm/BMW-V-Belt-...603096?vxp=mtr

It makes installing the 824mm AC belt SO MUCH EASIER than the Lisle 59370 stretch belt tool.

I still used the Lisle tool to remove the AC belt, as the official BMW tool is only meant for installation.

10-04-2017, 09:17 AM	#1
myculito Private 11 Rep 64 Posts Drives: 2011 BMW 335d Join Date: Jan 2014 Location: United States iTrader: (0)	Brand New Belt chirping / squealing ??? So, I recently started this thread after my harmonic balancer failed: http://www.e90post.com/forums/showthread.php?t=1425970. I put on the new accessory belt that I bought from ECS, but I re-used the AC belt Although the repair was successful, I noticed that the belt (pretty sure it's the accessory belt is squeaking). On start up, there is a noticeable chirp that's less than a second. But from time to time, the belts will audibly squeal for a couple of seconds, and then goes away. It's not all the time though. In my research, it appears that ECS gave me the belt Contitech 6K X 2065. Looking at the BMW OEM number, the belt should be a Contitech 6K X 2063. Can someone shed some light on this? Thoughts?
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10-04-2017, 09:49 AM	#2
PerfectAce Second Lieutenant 107 Rep 202 Posts Drives: 2011 335d Sport Join Date: Jun 2017 Location: Austin, Texas iTrader: (0)	I don't think the 2065mm belt is your problem. Not sure why there is a discrepancy, but the tensioner will take out the small amount of slack. I'm using the 2065mm belt and haven't heard a peep from it. On the other hand, you say you re-used the A/C belt. It's a known issue that the original 830mm belt would occasionally squeal and BMW recommended that the belt be replaced with an 824mm. But if that old belt wasn't squealing before, why would it start now? My first thought is that your A/C belt may not be properly seated on the A/C compressor pulley. When I installed mine, it had a tendency to slip toward the front by one groove. I had to take the belt off, line it back up, and when turning the crank use my other hand to push the belt toward the engine block to prevent it from slipping out. If you're certain that the belt is properly seated in all six grooves, then I would say that you need to try putting the 824mm belt on.
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10-04-2017, 09:59 AM	#3
335dsleeper Banned 389 Rep 1,623 Posts Drives: 09' 335d 10'35D Join Date: Dec 2015 Location: Suffolk, va iTrader: (0)	Stretch belts like the AC belt should never be reused.
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10-04-2017, 01:50 PM	#5
myculito Private 11 Rep 64 Posts Drives: 2011 BMW 335d Join Date: Jan 2014 Location: United States iTrader: (0)	perhaps it is the AC belt then. But why would there be a recommendation for an 824mm AC belt, when the OEM version is 830mm?
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10-25-2017, 04:07 PM	#11
myculito Private 11 Rep 64 Posts Drives: 2011 BMW 335d Join Date: Jan 2014 Location: United States iTrader: (0)	Just a follow up to this: I bought the official BMW install v-belt installation tool (part # 110330), similar to this listing: https://www.ebay.com/itm/BMW-V-Belt-...603096?vxp=mtr It makes installing the 824mm AC belt SO MUCH EASIER than the Lisle 59370 stretch belt tool. I still used the Lisle tool to remove the AC belt, as the official BMW tool is only meant for installation.
	Appreciate 0 Quote