Belt rattles under load (AC turned on)

[krook]

I recently changed out my S/C belt, but that sucker still rattles under load (i.e. when the AC is on). I had a hell of a time with the length, so I hope the one I put in was correct: 89 1/2 inches. I think the one I had on there was 90 in...

anyway, because it's still rattling, even with the smaller size belt, does that mean something else is wrong? should i change out the dynamic tensioner?

[Gibson99]

the tensioner SHOULD bounce a little under load at idle. it tends to smooth out once you come off idle. if it bounces so bad that you hear the belt chirping, then either your belt is too long or the tensioner is worn out and needs to be replaced. pray that the alternator pivot bolt isn't siezed up.

[krook]

the tensioner SHOULD bounce a little under load at idle. it tends to smooth out once you come off idle. if it bounces so bad that you hear the belt chirping, then either your belt is too long or the tensioner is worn out and needs to be replaced. pray that the alternator pivot bolt isn't siezed up.

the belt's not really chirping--it just rattles like a muthaf*cker!?? it's insane, i've never really watched it before. but once the AC kicks on: rrRRrRrRRrAaattTTTTTlLllllLLeeeeEEEe

i should post a video.

also, my idle is really LOW. i'm assuming that's why my belt rattles when the AC is turned on since the compressor is spinning faster than the SC and its pulleys...? (is that a safe assumption?)

[Gibson99]

if it idles below about 600 rpm then yes it'll rattle. mine does too if i bog it when trying to take off slowly/quietly (stickshift).

clean your throttlebody and IAC area thoroughly to try and cure that low idle. normal idle is 700 rpm.

i really think the low idle is your core problem here, so fix that first.

[krook]

if it idles below about 600 rpm then yes it'll rattle. mine does too if i bog it when trying to take off slowly/quietly (stickshift).

clean your throttlebody and IAC area thoroughly to try and cure that low idle. normal idle is 700 rpm.

i really think the low idle is your core problem here, so fix that first.

ok thanks. i'm gonna try that tomorrow and see what's up. this all happened after i changed my SC oil, so i'm gonna triple-check all the connections once again...

[RON]

I recently changed out my S/C belt, but that sucker still rattles under load (i.e. when the AC is on). I had a hell of a time with the length, so I hope the one I put in was correct: 89 1/2 inches. I think the one I had on there was 90 in...

anyway, because it's still rattling, even with the smaller size belt, does that mean something else is wrong? should i change out the dynamic tensioner?

I have heard 88.5"..not sure, since I have 5.5lbs and no pulley. The original STOCK SC belt for the 3.2" Pulley was 2222MM or 87.5" (no tensioner). That's my belt size. I think your belt is too big.

[RON]

Here's a belt tenioner I just got. Gates Krikit 91107.

the SC belt should be tensioned to 70-90 lbs (120lbs brand new).

Link:
http://www.rockauto.com/catalog/raframecatalog.php?catalog=64&partnum=91107&a=FR64-91107