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Gen4 VQ Belt Squeak Weirdness

4K views 9 replies 3 participants last post by  amc49 
#1 ·
So, I have been plagued by the sporadic cold weather squeal through the winter which would go away once warmed up. Then come spring all was good, except above 2500rpm I'd get this weird rpm related chirping which got quite loud. Chirping happened regardless of parked or driving and with or without AC on. I prelim'd it as one or more of the idler pulleys/auto tensioner.

Removed the wheel on the weekend to see if I could narrow it down...no dice. I removed then removed the belt and the fun began.

1. auto tensioner pulley spins quite freely, but as it slows down it has a kind of metallic ringing/ting ting noise. There is some lateral play in the bearing

2. upper idler also spins quite freely, but makes a rubbing sound as it slows down, more play on this pulley

3. lower idler spins smoothly and silently, but not freely. It comes to stop in a revolution or two, unlike the 5-10 the others manage. No play, no noise just a sense of a little drag.

I checked the other pulleys, and notice that

4. small amount of play in the a/c compressor clutch pulley (no noise but definitely a little lateral movement when clutch not engaged)

I also noticed that when cold, the chirping happened even at idle. On a whim and a hunch, I used the back of a screwdriver to gently depress the edge of the ac clutch against the spinning pulley (engine running) but not enough to cause rotation, a little puff of rust dust and the chirping was gone!

I will continue to test, but I think I have resolved the annoying squeak symptom, but have now discovered other wear areas of concern.

Anyone with thoughts or input into what is acceptable bearing play on the idlers and AC pulley should feel free to jump in!
 
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#2 ·
Fun conclusion post. Short story:

Turned out to be the one that I actually thought was ok and the auto tensioner is frickin' near impossible to remove without removing the PS pump/pulley....read on

As above the auto tensioner and upper idler had play and probably needed replacing, but the lower idler which had no play had clear evidence that it was rubbing on the long mounting bolt. Seems the lower idler actually has two? bearings inside and from what I could see the inner bearing seal had gone a long time ago. The inner race was rubbing on the bolt, you could see the shiny patch where it made contact on removal.

Fun fact #1 the Gates part is almost twice the Dayco price for this pulley, I went Dayco for this part and saved $30 (~50%)

Fun fact #2 the Gates parts come with new bolts and dust shields, which are useless, I couldn't even get a stubby 17mm socket on the replacement bolt, even using a simple 3/8" breaker...just wouldn't fit. I cleaned up the original shields (much better quality) and re-used the original 13mm bolt. Next time I'll just buy all Dayco and not pay 'extra' for the useless hardware included with the Gates parts.

Fun fact #3 the top auto tensioner assembly mounting bolt is directly behind the outer rim of the PS pulley. No way you can get any kind of socket on this. I wound up using extra long box end 13mm wrench with a slight angle of 15'?? I was just able to get this on enough of the bolt head to break it loose, then had to put it on another 50x to get the bolt far enough out to remove with fingers

Fun fact #4 You cannot remove both the upper and lower auto tensioner bolts with tensioner in the same position. The lower only comes out when the tensioner is free, and the upper only comes out when the tensioner is locked in place with your 6mm allen key through both holes. So this means you have to lock it to remove the belt, unlock to loosen but not remove the lower bolt, relock it and work on the upper bolt, then careful unlock it again to remove the lower bolt and assembly. Installation is the reverse of this nightmare.

Fun fact #5 For whatever reason I removed mine still in the locked position...so to get your allen key back out...I used some vice grips to 'pinch' the two parts enough to remove the key, but when you unlock the vicegrips...it expands more than they do, so you have to tap the tensioner off the vicegrips...sigh.

All good now though...$180CDN later (I put a new belt on too).
 
#4 ·
Fun fact #3 the top auto tensioner assembly mounting bolt is directly behind the outer rim of the PS pulley. No way you can get any kind of socket on this. I wound up using extra long box end 13mm wrench with a slight angle of 15'?? I was just able to get this on enough of the bolt head to break it loose, then had to put it on another 50x to get the bolt far enough out to remove with fingers
Turning a wrench eight degrees at a time sucks. Things like that always make me wonder how cars manage to get assembled in the first place.

FFun fact #4 You cannot remove both the upper and lower auto tensioner bolts with tensioner in the same position. The lower only comes out when the tensioner is free, and the upper only comes out when the tensioner is locked in place with your 6mm allen key through both holes. So this means you have to lock it to remove the belt, unlock to loosen but not remove the lower bolt, relock it and work on the upper bolt, then careful unlock it again to remove the lower bolt and assembly. Installation is the reverse of this nightmare.
Congratulations on figuring it out, though. I would have gone 90%, become stuck, and put it all back together without fixing anything.

Fun fact #6 you cannot torque the upper auto tensioner bolt, or the upper idler bolt due to clearance issues. I used the R. U. Gudenteit method. The auto-tensioner torque is supposed to be 25 ftlbs, and the idler bolts 29.5 ftlbs ish. Page EM-121 if you care to double check.
When this came up on my motorcycle, we just took a 12" wrench and a spring scale. Pull on the scale to tighten until the correct torque. Bit more difficult when the only wrench that fits is 6" and your scale doesn't go up high enough.

Glad you got it all working again.
 
#3 · (Edited)
Fun fact #6 you cannot torque the upper auto tensioner bolt, or the upper idler bolt due to clearance issues. I used the R. U. Gudenteit method. The auto-tensioner torque is supposed to be 25 ftlbs, and the idler bolts 29.5 ftlbs ish. Page EM-121 if you care to double check.

Fun fact #7 the Gates parts were Made in Canada, eh?!
 
#5 · (Edited)
^^ Thanks for the spring scale idea! I now have a *real* reason to get one...

Now I can finally answer M. I. Teitenhoff?
 
#7 ·
Update...been about a year...and that's about as long as my Gates micro-V belt lasted before becoming a squeaking nightmare. Have replaced with a pretty swish looking Continental belt for now.

Suspect the root issue is with the bearing play I have on my compressor pulley...so I've ordered the AC clutch kit (coil, bearing, pulley, plate and hardware) ($55) and will soon see how I get on with the 'great compressor clutch or coil replacement challenge'....

In the meantime, I no longer sound like an invasion of 6' locusts driving down the road...
 
#8 ·
FYI, I have seen dirt buildup concrete in pulley grooves in such a way that the pulley looked perfect until you looked super close to realize that the very bottom of the grooves was just built up enough to lightly lift the belt free of the groove sides to then squeal. I could only barely tell it in bright sunlight, and the dirt was so hard it took like an hour with a sharp knife to chisel it out of the grooves to be back to 100% clean grooves there. Before that every belt I put on made noise and all pulleys and tensioner in perfect shape, going nuts there for a bit. The dirt was deposited so perfectly it looked like part of the pulley.

Part of a bad bearing is feel as well, I have seen a certain smooth rolling of a bearing with no looseness that simply felt TOO smooth and easy and no other way to describe it. The bearing DNFed like a week later. Thinking the bearing was still tight but completely 100% out of lube to go bad shortly thereafter, it was like spinning one with all the lube washed out with solvent.

Of late I have been practicing carefully removing one side seal to relube a bearing and reattach the seal to get essentially a new bearing if it is still tight. That idea seems to be working out pretty good. You have to be pretty picky about it though. Just 'rebuilt' an a/c clutch maybe 3 months ago doing that and it's working fine, as is the tensioner roller and idler.
 
#9 ·
Thanks for the tip about the dirt in grooves, could be a possibility, especially if some of it is rust dust which will polish nicely and look like the original base metal. I did wash each pulley down with some brake cleaner...reason for that was when my inner CV joint failed, it slunch axle grease directly at the main tensioner pulley...which of course evenly distributed it all over the belt and every pulley. Idea was to wash the pulleys and replace the belt...however, I replaced it with the one I had removed two years previous (don't ask why I still had it)....and it worked great for a day before screaming endlessly (which I chalk up to the citrus solvent I cleaned the idler pulleys with (not wanting to use the chlorinated brake cleaner on the painter pulleys)...I figure that softened and quietened the back side rubber...and once it evaporated...the squeal came back x10! There was no cracking of the v-ribs or any indication that the ribbed side of the belt was contaminated or otherwise defective...however the flat back side of the belt had a definite polished/hardened look/appearance to it...so my theory is that the back was squealing against an idler pulley.

Regardless, the supple new Conti belt, which actually has a textured back side, eliminated every peep from the system. Who would have thought a $12 belt could do that so absolutely? Anyways, I've done with Gates products on VQs...they just don't last.
 
#10 ·
FYI, never, NEVER use a (Goodyear?) Gatorback belt............the one with the trick notches in it. I stupidly bought one even while thinking 'those notches are all stress risers' and about 3 months later proven right, and lost a really good job interview over it when the car suddenly DNF'ed. Belt came apart and stripped part of it to insert at the water pump and destroyed that too (new of course). On looking at the belt every single notch there was cracking deep into the rest of the belt body, a true piece of crap that I paid way too much for.
 
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