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Serpentine Belt Question?

9K views 27 replies 9 participants last post by  jammgm 
#1 · (Edited by Moderator)
I came across this thread for replacing the serpentine belt. Nice procedure! :thumbsup:
Does anyone know approximately when the belt should be replaced? Mine is the original belt of 15 years and 113,000 miles and was told it was fine when I last had it checked.

I have a clicking noise coming from somewhere near the pulleys when the car is idling in gear and going to pop the belt off to find what's causing it.
I figure if it needs to be replaced, I'd do that too.

Can anyone tell me when a serpentine belt should be replaced or how to check if it needs replacing?
I have a clicking noise coming from somewhere in the pulleys when the car is in gear at a low idle and need to pop it off to find the cause and replace if needed. Mine is the original belt of 15 years and 113,000 miles.

I found all the forum links on how to replace it so I'm good there. Thanks everyone!

Thanks,

Jim
 
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#5 ·
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Mine is the original belt of 15 years and 113,000 miles.
IF it is the original - you are long overdue -

I have a clicking noise coming from somewhere in the pulleys
you usually do NOT get a clicking noise from a belt -
that sound IS usually from an idler pulley going bad -

with the tension off the belt - there should be NO play in the idler pulley -
if there is - replace it -

while your at it - check the water pump drive belt - and pulleys -
 
#3 ·
you sure it's the original? Does the belt have any cracks in it? FSM states:
  1. Remove the drive belt.
  2. Run the engine for no more than 30 to 40 seconds, in order to confirm that the engine noise disappears.
  3. Inspect the power steering pulley for proper alignment.
  4. Inspect all other pulleys for excess paint, debris or pills in the grooves.
  5. Clean the pulleys with a wire brush, as necessary.
  6. Removal:
  1. Install a 1/2 inch drive extension into the belt drive tensioner (6).
  2. Push down on the extension to release tension.
  3. Remove the drive belt from the power steering pump (13
  4. Slowly return the tensioner to the original position.
  5. Remove the belt.
INSTALLATION
  1. Thread the drive belt through all the pulleys except for the power steering pump (1) and the drive belt tensioner (6).
  2. Insert a 1/2 inch drive extension into the drive belt tensioner.
  3. Push down on the tensioner and feed the belt around the tensioner wheel.
  4. With the tension applied, complete the belt routing. Make sure the belt is properly seated in all pulleys.
  5. Slowly return the tensioner back to its original position. This will apply tension to the drive belt.
  6. After installation, check the belt for proper seating on the pulleys, proper routing and alignment.
  7. Start the engine and check for proper belt and accessory operation.
 
#9 · (Edited by Moderator)
You read wrong. These belts will last well over 25-30K as evidenced by yours. Cracks are normal, missing chunks are not.

Don't want to start a poll here but, I have never met someone who actually has broken a serp belt. I think a crazy beaver could chomp on a serp belt and it would still work fine.
I agree. While I have changed more V belts than I care to remember, I have yet to change a serp belt. These things are totally different animals.
 
#6 ·
Guys, thanks for the quick feedback! :thumbsup:

I'm pretty sure it's the original belt since I'm the original owner and don't recall ever replacing it. I'll check for cracks as well.
As for the clicking noise, my suspicion is that the idler pulley is bad which would be better than anything else being bad.
 
#8 ·
Re: Changing the Serpentine belt on a VIN Y Northstar V8

Even the GM service manual says that, unless the Kevlar backing is shredding or the V-grooves and/or ribs are missing chunks, the belt is serviceable. Cracking across the V-ribs is normal and is not cause for replacement.

BUT - 100,000 miles is MY absolute limit as to how far I want to test fate. (Especially the way I exercise the engine) Think of the strain on the ribs when that belt bends backwards to turn around a smooth pulley.
 
#10 ·
This thread may look a bit weird - the OP posted the identical question in another thread in Engines, Northstar. They have been merged here.

jammgm, Please do not multiple post the same question in different forums - let one work for you - it keeps all advice on the same question in the same place for all to see. Thanks.
 
#12 ·
I've only had them break when something seize or damaged pulley.
I would change my Park Ave belt every couple years because it was such a pain and if it broke on the road that bill was going to hurt. Have to remove engine mount as the belt goes through it. Got it down to 3 hr's or so.
 
#15 · (Edited)
The time for changing a serpentine belt is when the top ridges of the pulleys touch the bottom of the grooves in the belt.
The belt looks like this VVVV so do the pulley. The V's of a brand new belt are slightly deeper than the pulley. So the pulley rides on the peaks of the belt, the peaks of the pulley are not touching the bottom of the groves on the belt (see below):
VVVVV - Belt
vvvvv - Pulley
As the time pass the belt sunken more and more into the pulley. When the pulley peaks are touching the bottom of the belt groves then you have greater friction and may start hearing belt squeaks (I assume ideal condition no contamination/misalignment on the belt because that can cause even a new belt to squeak). The belt does stretches in time (neglectable anyway) and is nothing that the tensioner spring cannot compensate.
They say this is the time when the belt should be replaced if there are no obvious cracks on the belt.
If there are cracks (few are normal) more than 3 per inch are considered end of serviceable life.
So whichever comes first is the end of the belt.
I am sure if pretty much impossible to detect when the belt is sunken all the way into the pulley grooves. Squeaks can be caused by other things so a squeaky belt doesn't necessarily means belt is done.
So the best practice is, if you have repetitive cracks all around the belt (across the V's) or there are many missing chunks on these V's or the belt squeaks (and alignment is OK and there is no contamination) then you may consider replacing it.
Our cars will run for at least 20 miles with a broken accessories belt (until will drain the battery) or few miles with the broken WP belt until will overheat (and then another 20-30 miles in limp mode but DON'T try it!).
So breaking a belt is annoying but nothing else.

I changed both my belts because the accessories belt had few cracks (nothing that will classify in the 3 per inch) when the vehicle was 13 years old (~150K). I could have easily run on the same belts today.
Think the timing belts are usually replaced after 60K (and we all know what a broken timing belt do to an engine), accessories belts are nowhere near as critical. But on the other hand are cheap so if you are the kind of person that likes to play safe even if the belt shows no signs of wear but you get nervous because of the age or mileage by all means have it replaced is only a 10 minutes job.
 
#17 ·
Thanks again for the all the info and discussion.
I'm going to replace it anyway since I have to pop it off to find the cause of the clicking noise.

Sub, I posted this separately because I didn't see my original post and thought it wouldn't be shown since it dated back to 2009. I'll be sure to only post one question next time.
 
#18 ·
No problem - when you find a thread, no matter how old, on a problem you are having and then post to it, it jumps to the 'head of the list'. That's perfectly OK if that's where the current discussion lies - but when you start two threads on the same subject in different forums, then it's difficult to keep up on what has been advised where.
 
#20 ·
With some assistance from a neighbor and a stethoscope, I found the clicking noise is coming from the tensioner pulley.
I picked up a replacement tensioner and new belt and going to replace them this weekend.
There's not much room to work with so wish me luck and I'll keep track of all the choice words I'm going to use.

BTW, does anyone know how much to torque the tensioner bolt?
 
#22 · (Edited)
?? That's a LOT for those 2 10mm tensioner studs. Even for the tensioner pulley center shoulder bolt. GM service manual ???

(The 2002 manual says 89 in/lb (~7.5 lb/ft) for the tensioner bolts [and the nuts], silent on the pulley shoulder bolt. 13mm hex head. Judiciously tight.)

jammgm, several water pump drive/tensioner pictures and diagrams in my albums - the Community tab, Albums, the red Seville. 2 albums, 6 pages.

You could have bought just the pulley at a NAPA for about $24. It's totally replaceable - unless the tensioner arm/spring is toast. Also look in RockAuto, your car/year/system, engine, belt drive, 3-rib pulley. Gates.
 
#25 ·
For reference, if the pulley itself is noisy/needs replacement, you don't need to remove the tensioner arm - use a small crescent wrench on the square lug molded into the arm - lever the arm so as to slip off the belt. Now you can use a socket to remove the center bolt and pulley. Bolt on the new pulley, tighten the bolt (that action will move the arm toward the firewall - not to worry), replace the belt in the process.

............ There are two independent sealed bearing pulleys in the accessory drive: The idler and tensioner pulleys. Consider that on a high mileage engine also.
 
#26 ·
Guys,
I just finished replacing the pulley and belt. The job wasn't too bad and didn't have to use many choice words. :bouncy:

I removed the battery, and loosened the a/c and power steering line brackets to give room to remove / replace the belt and also give me the room I needed to get at the tensioner. I removed the tensioner to replace the pulley which made it easier.

Sub,

Thanks for the tip to just replace the pulley versus the entire tensioner. You saved me some good $$.
I'd buy you a drink or two if you were closer to CT. :alchi:

Also just saw your note about replacing the pulley with the tensioner on the car. Not sure how easy that would be since the bolt was a torx and very hard to loosen. Had to put the tensioner in a bench vice to hold it while loosening the pulley bolt.

As with all the good info/tips you provide, I'll take your word for it. :bows:
 
#27 ·
The Torx bolt is a new one on me - anyone else have a Torx instead of a 13mm head hex bolt ?

(The end of the intake cam - water pump drive pulley - threads has a plastic cap with a Torx head, but that's strictly for thread protection. The threads in the cam snout are used with special GM extractor/installer tools for the TIGHT pressed-on drive pulley.)
 
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