BMW E46 Fanatics Forum banner

1 - 17 of 17 Posts

·
Registered
Joined
·
0 Posts
Discussion Starter #1
I have a 2003 330ci, 3 days ago i changed my serpentine belt as well as the tensioner pulley, and idler pulley;:banghead: but now im getting a loud squealing noise from what i think is the idle pulley. can someone please give me their input on what it may be. i sprayed belt conditioner on the belt before installing it could that make if squeal??:facepalm:
 

·
Registered
Joined
·
1,180 Posts
While the car is running spray some wd40 into the idler pulley bearing and see if the squeal stops. Found out mine was bad that way.
 

·
Registered
Joined
·
26,422 Posts
Did you notice the alignment pin on the idler pulley?

Look from the side and see if things seem perfectly square to the belt.

I'm pretty sure most here say 'no' to belt dressing...so when you get belt off to fix whatever it is, you might wash that stuff off, if you can...and make sure belt goes back on the same direction...remember if the writing on the belt is right side up or down and put it back that way...in case you didn't know to do that.

Since that's all you did, and got squeal, I think it's probably that pin is off and you're not square, or that belt dressing.

If that's not it, take a hose about 5' long and use it as a stethoscope and isolate the sound.

HTH
 

·
Registered
Joined
·
0 Posts
Discussion Starter #6
Did you notice the alignment pin on the idler pulley?

Look from the side and see if things seem perfectly square to the belt.

I'm pretty sure most here say 'no' to belt dressing...so when you get belt off to fix whatever it is, you might wash that stuff off, if you can...and make sure belt goes back on the same direction...remember if the writing on the belt is right side up or down and put it back that way...in case you didn't know to do that.

Since that's all you did, and got squeal, I think it's probably that pin is off and you're not square, or that belt dressing.

If that's not it, take a hose about 5' long and use it as a stethoscope and isolate the sound.

HTH

im going to upload a picture of the belt, can you tell me if i installed it right.:)
 

·
Registered
Joined
·
26,422 Posts
I can't tell anything from that; maybe someone else can, but if you notice the pulley isn't parallel with the belt, that might be what I said....that the idler pulley isn't aligned properly.

Your eye will be better than a photo. Also, the belt dressing seems to cause squeaks not eliminate them.
 

·
Registered
Joined
·
0 Posts
Discussion Starter #11 (Edited)
I can't tell anything from that; maybe someone else can, but if you notice the pulley isn't parallel with the belt, that might be what I said....that the idler pulley isn't aligned properly.

Your eye will be better than a photo. Also, the belt dressing seems to cause squeaks not eliminate them.
i just check out the idler pulley and made sure that it was into the groove of the alternator and it is
 

·
Registered
Joined
·
26,422 Posts
I can't tell if the whole thing is square or not...

One other outside chance I can think of...other than getting belt dressing cleaned off?

When you pull the idler pulley bolt, it's also supporting the top alt bracket. It is possible for the bolt to be through the front of alt, and not the back, thus tilting the alt enough, that you'd attenuate the squeal (sort of the same with wheel bearings). Make sure, with your magic xl50, that that bolt passes through both brackets on the alt.

Listen with hose, don't assume it's from the work you did, it might be from the work you didn't do...AC pulley I think was mentioned...PS pumps have a bearing and a plastic pulley that does crack.

Did you reuse the AC belt or replace that new. Did you make sure you got the right number of ribs on the belt? Did you buy incredibly cheap replacement pulleys? (Sorry, new parts do go bad...crappy new parts just sooner!)
 

·
Registered
Joined
·
241 Posts
Here is a picture of what DMAX is talking about on the idler pulley installation :

http://tis.spaghetticoder.org/s/view.pl?1/00/32/62



Installation:
Locking device of auxiliary tensioning roller must snap into groove on alternator.
Hmm, I just did all my belts and pulleys, but I confess that I don't understand this... The groove of the alternator? It's hard to see from the pic.

Been driving for a couple of weeks now with no problem, but maybe I should check this.
 

·
Registered
Joined
·
0 Posts
Discussion Starter #15
I can't tell if the whole thing is square or not...

One other outside chance I can think of...other than getting belt dressing cleaned off?

When you pull the idler pulley bolt, it's also supporting the top alt bracket. It is possible for the bolt to be through the front of alt, and not the back, thus tilting the alt enough, that you'd attenuate the squeal (sort of the same with wheel bearings). Make sure, with your magic xl50, that that bolt passes through both brackets on the alt.

Listen with hose, don't assume it's from the work you did, it might be from the work you didn't do...AC pulley I think was mentioned...PS pumps have a bearing and a plastic pulley that does crack.

Did you reuse the AC belt or replace that new. Did you make sure you got the right number of ribs on the belt? Did you buy incredibly cheap replacement pulleys? (Sorry, new parts do go bad...crappy new parts just sooner!)
I bought the parts from the stealership and I haven't replaced the ac belt since it is still fine.
 

·
Registered
Joined
·
706 Posts
Try this:

Remove a/c belt, and start the car. If the noise is gone you know its with the a/c pulley and/or belt. How does the a/c pulley feel, does it spin too easy or does it stop after a couple of revolutions when spun by hand?

If the squeal is still there, take off the main drive belt, and start the car again. Do this for a VERY breif period of time only as the water pump is driven by the belt. Also make sure you do this when the engine is cold. Make sure the noise is not there. If the noise is not there, you have 100% isolated it to something on the drive belt. Check all pulleys at this point, including alt/powersteering/wp pulleys. I will again re-iterate, do NOT run the car for any length of time without this belt attached. Literally it should take 10 seconds tops to figure out if the noise is there/gone.

You *may* have to clear check engine light codes after starting without the main belt, not sure on that with this car.

Good luck
 

·
Registered
Joined
·
26,422 Posts
I bought the parts from the stealership and I haven't replaced the ac belt since it is still fine.
You said you replaced the belt. I guess you mean that you didn't. :lmao:

Get old belt off and put new ones on. When you said you replaced it, of course, I'm going to believe that. Putting dressing on an old belt that looks fine is probably the issue.

Whoever didn't understand the groove with idler pulley...there's an alignment pin on the back of the pulley, and mates in a notch on the alt...if it's not in the hole, the pulley will be pushed out a bit and not square with the belt. You'll see more pulley on one side of the pulley than the other.
 
1 - 17 of 17 Posts
Top