# AC belt tensioner bolt sheared off



## Tyrone (Apr 17, 2003)

A few days ago I noticed a strange noise that sounded like a pulley, but I didn't check very thoroughly and thought nothing of it. Then Thursday on my way home I heard an awful screaching sound as I took my exit. At first I thought it was my tires or those of the truck behind me, but I shut off the AC compressor and it went away. I was VERY worried at that point, since just last year a compressor failure resulted in $1300 worth of repairs.

Yesterday I looked more closely and discovered that the AC belt was extremely loose and also cracked. What I didn't notice was that the belt tensioner was completely free at the top and flopping around! The top bolt just next to the idler pulley had somehow sheared off into the compressor bracket, right where the threads begin. It took my neighbor and me a couple hours to drill the bolt and use a bolt extractor to remove it. Thanks Lou!

I bought both belts to replace, and ordered all new bolts, washers, and nuts for both tensioners. Right now I hope that we didn't damage the threads trying to get the bolt out and that no harm was done to my A/C compressor. The AC belt and tensioner are off right now until the bolts arrive next week. They were all special order parts. I guess you may want to consider replacing these bolts when doing a belt change, as they weaken over time. At least with a bunch of stuff off the car, I got to spend a few hours cleaning hard to reach areas of the engine bay.


----------



## kowached (Jun 20, 2003)

*Sorry to hear big guy.*

While you've got the tensioner out, you might want to disassemble th etensioner pulley far enough so that you can get some fresh lube inside of the ball bearing that it spins on. I seem to remember Jim Cash doing this at one point.


----------



## Tyrone (Apr 17, 2003)

kowached said:


> While you've got the tensioner out, you might want to disassemble th etensioner pulley far enough so that you can get some fresh lube inside of the ball bearing that it spins on. I seem to remember Jim Cash doing this at one point.


Thanks! I do remember that. I should have his post saved. I decided to spend a few hours cleaning the engine bay while the intake air tubing and fan shroud were off. I took off the engine cover so I could also clean the intake manifold and also removed the headlights for more clearance in those areas. Turned out to be a long project! After using the degreaser (Würth Citrus) I'm sure the bearings would benefit from extra lubrication.

I should soon be exiting the 70K-100K mile stage of the car's life where things start to go south. After this it'll be suspension work then clutch. Can't wait for the windshield to be put in tomorrow!


----------



## roxnadz (Jan 10, 2003)

Hey Tyrone...

Was the pulley noise sort of a scraping/squeaking type sound? Did it happen at any specific time, say, when the car was cold?


----------



## Tyrone (Apr 17, 2003)

roxnadz said:


> Hey Tyrone...
> 
> Was the pulley noise sort of a scraping/squeaking type sound? Did it happen at any specific time, say, when the car was cold?


Malcolm, the initial noise was as you describe and not very loud. Sounded like something turning, but scraping a bit as if it weren't greased well. I could hear it most right after starting the car in the morning, but I didn't check any time other than that. I assume it was making the noise all the time. Once the bolt finally did give, there was a TERRIBLE screeching sound from the belt until I turned the AC compressor off. Right now the tensioner and belt are off until the new bolts come in this week. Hopefully with the climate comfort windshield I had installed today I won't need the AC!


----------



## roxnadz (Jan 10, 2003)

Mmmmm hmm...that's what I thought. My car's making the exact same sounds. Do you have a list of the parts you got? If not, no biggie, I can search the ETK. I already have the belts as mine have some serious cracks.

Thanks Tyrone


----------



## Tyrone (Apr 17, 2003)

roxnadz said:


> Mmmmm hmm...that's what I thought. My car's making the exact same sounds. Do you have a list of the parts you got? If not, no biggie, I can search the ETK. I already have the belts as mine have some serious cracks.
> 
> Thanks Tyrone


Your '99 is going to have slightly different parts, but I sent you an e-mail with the appropriate diagram and p/ns. I replaced only the hardware (except bolts holding pulleys), and not the actual pulleys or tensioners. In my case the bolt was completely out and the tensioner was free to move around, but your noise could be that one of your pulleys needs to be replaced. As kowached says you can pack more grease into it, but I haven't done that myself. Jim Cash says it possible, but you can cause damage removing the bearing if you are not careful.


----------



## Ågent99 (Jan 7, 2002)

Tyrone said:


> ...Hopefully with the climate comfort windshield I had installed today I won't need the AC!


I _think_ BillP had this windshield installed in his 540i under warranty and now he cannot use his V1 due to the metal content within the windshield. However, he sold it on eBay (like 1 or 2 year old V1) for damn near what he paid for it!

_
There's a sucker born every minute.
_

Who said that? 

Chris


----------



## PropellerHead (Jan 3, 2002)

Ågent99 said:


> _
> There's a sucker born every minute.
> _
> 
> ...


The Circus Guy! PT Barnum.. (I think anyway) Bonus if you know his last words....


----------



## Tyrone (Apr 17, 2003)

Ågent99 said:


> I _think_ BillP had this windshield installed in his 540i under warranty and now he cannot use his V1 due to the metal content within the windshield. However, he sold it on eBay (like 1 or 2 year old V1) for damn near what he paid for it!
> 
> _
> There's a sucker born every minute.
> ...


That's okay. I don't use a radar detector anyway. To me the cooler interior is much more important.


----------



## Ågent99 (Jan 7, 2002)

PropellerHead said:


> The Circus Guy! PT Barnum.. (I think anyway) Bonus if you know his last words....


Arrgghhh...now I'll waste half the day looking for it but I don't know off the top of my head. :irate:

Chris


----------



## PropellerHead (Jan 3, 2002)

Ågent99 said:


> Arrgghhh...now I'll waste half the day looking for it but I don't know off the top of my head. :irate:
> 
> Chris


"What were the days' final receipts?" :keel:


----------

