low RPM belt Rumble

[vettatude]

Ok, I think I have the low RPM belt rumble problem. However I have found two TSB's that seem to cover almost the same problem. One replaces the alternator and tensioner, and the other replaces the tensioner and the belt. My car is out of warranty and I'm going to have to pay for these myself. Which one should get rid of the problem? I really don't want to buy a $350 alternator. Also, should I get the tensioner for the 2001-Up cars? Do you think the tensioner and a new belt will be enough? Or should I invest in an aftermarket tensioner that isn't spring loaded but adjustable with a threaded bolt and nut?

Thanks

 

[mick_s3]

Ok, I think I have the low RPM belt rumble problem. However I have found two TSB's that seem to cover almost the same problem. One replaces the alternator and tensioner, and the other replaces the tensioner and the belt. My car is out of warranty and I'm going to have to pay for these myself. Which one should get rid of the problem? I really don't want to buy a $350 alternator. Also, should I get the tensioner for the 2001-Up cars? Do you think the tensioner and a new belt will be enough? Or should I invest in an aftermarket tensioner that isn't spring loaded but adjustable with a threaded bolt and nut?

Thanks

It's probably the AC belt, change it. While you are at it change the serpentine belt, and if you have over 50k change the tensioner pulley.

Cheap fix and with a little patience you can do it yourself in an hour or so. The AC belt is tough from up top.

Did it last weekend, fixed my rumble/squeek.

I did see a tsb or whatever about the idler pulley. I didn't bother to change it because it seemed just fine.

Mick

 

[c4c5specialist]

Hi there,
There is also a revised calibration for the PCM to also consider.
The rumble may not always go away with the tensioner and belt.
I am thinking that you have an automatic.
If so, replacing the alternator with the revised one with a decoupler pulley will eliminate the noise.
Allthebest, c4c5

 

[mick_s3]

Hi there,
There is also a revised calibration for the PCM to also consider.
The rumble may not always go away with the tensioner and belt.
I am thinking that you have an automatic.
If so, replacing the alternator with the revised one with a decoupler pulley will eliminate the noise.
Allthebest, c4c5

I did notice once I got my belts on that I could here a little noise coming from the alternator.

When I get around to swapping that bad boy out, if I just order a replacement Alt, will I get the "new and improved" model by default or will have to tell them explicitly that that is the one I want?

What is the difference with the tensioner pulleys exactly?

Thanks again C4C5 you rock.:BOW

Mick

 

[vettatude]

I don't want to pay $350 for a little noise. I might try a tensioner with a new belt. One TSB specifies a 97-2000 tensioner, and the other specifies a 2001+ tensioner. Gates is supposed to be coming out with a new type of belt that doesn't stretch as much as stock. I think the PCM update is merely a bandaid for the problem, all it does is raise the idle RPM so you don't dip down low enough to get the vibration. If you want an alternator, it is a specific part for 2001+ A4 only cars.

Thanks for the input.