2004 Envoy squealing when up to speed, already replaced belt and tensioner

[e-iowa-o]

I can't reproduce the squeal when parked. Not present if I hold down breaks and put it in gear then increase RPMs. Only happens when under load and up to speed. Starts at about 45 MPH and gets worse as speed increases. if running 60 and squeal is constant and I let off the accelerator to coast it stops.

Replaced belt first, noise still present, then tensioner and replaced belt w one another cm shorter to be sure.

AC compressor and idler are out of the configuration. I only have power steering pump and alternator in the loop. I have never had either of those squeal before. I have replaced the PS pump a cpl times over the years but never the alternator. i know I have pressed the pulley on and off of the PS pump when I replaced those.

You guys ever had a PS pump or alternator squeal when motor is up to speed and going down th road? Or should I be looking somewhere else and i'm barking up the wrong tree, completely?

 

[Blckshdw]

I can't reproduce the squeal when parked. Not present if I hold down breaks and put it in gear then increase RPMs. Only happens when under load and up to speed. Starts at about 45 MPH and gets worse as speed increases. if running 60 and squeal is constant and I let off the accelerator to coast it stops.

This description tells me it's something in the wheel area, and not the engine bay, since it only seems to be present when the wheels are spinning at speed. When was the last time you had your brakes/hubs checked? Transfer case and front diff serviced on schedule?

 

[e-iowa-o]

I know one on my rotors are warped pads have plenty of life yet.. and have replaced th hubs a cpl times. I'll get it out on th road and lean it back an forth. Seems like a while back I thought I was getting that low hum but the squeal garnered more attention..

 

[e-iowa-o]

I'm pretty sure it's on th motor. I tried several formats and cldnt attach so finally figured out that it's not possible. Have never made a YouTube video so dunno if this link will work..

Well dang! I guess it did!

 

[2x1968muscle]

have you confirmed that your idler pulley bearings are ok ? It sounds like a bearing to me.
Or, I know you said you changed the belt, but did the parts guy give you the correct belt.

Hope you sort it out

 

[e-iowa-o]

There is no idler in the configuration. AC went out so idler and AC are out of loop and I have a shorter belt. I flexed the tensioner and got a belt that makes it sit at about 50% of it's range of movement. So only suspect either the PS pump or alternator. Fan clutch is fairly new, too.??

 

[TJBaker57]

Fan clutch is fairly new, too.

Did the noise begin after the fan clutch was replaced?? Or when the summer temperature arrived??

By rerouting the belt you reduced the belt contact area for the waterpump/fan combo. If the engine is now getting warmer due to the summer temps, perhaps the fan is now being commanded to run faster and this extra load is too much for the reduced belt to pulley contact area??

 

[e-iowa-o]

Well, the routing has been this way for several years and a cpl years. If I understand your reasoning, I don't think the belt to pulley area has ever changed. I'd think the power demand available to the fan wld not be any less as there is no resistance or drag from AC and idler.

 

[mrrsm]

What you are describing can be also caused by a Bad Water Pump Bearing that allows the Smooth Side of the Outer Orbit of The Water Pump Pulley-Fan to "Wobble" just enough at Higher RPM while in contact with the Smooth Side of the Serpentine Belt to "Skip Sideways...and Chirp". It is very subtle and can go on undiscovered damned near forever.

Have a look at an image I took while using a Tool I made to restrict the Water Pump Pulley & 4 Bolts enough to Break Loose the 'Jesus Nut' on the Electro-Viscous Clutch Fan Blade Unit. Notice the Gray "Wear"Area on the outer rim of that Pulley? THAT is what can cause this Annoying Sound from it constantly rotating "Out Of Round" and slipping sideways, back and forth (like Sneakers do on a Gym Floor) under the Serpentine Belt and will only disappear by replacing the Water Pump and Gasket.

 

[e-iowa-o]

I bet that's it.. there doesn't seem to be any play but That's probably what I'm lookin at. I thought I might get it to go quiet for a bit with a squirt of water. But, by th time I get th RMPs up an get moving down th road it's dried out enough to start chirp

 

[e-iowa-o]

I can't reproduce the sound while parked. So, maybe there a little distortion while up to speed or under load?

 

[JayArr]

I've been through so many water pumps I'm convinced they were not designed robustly enough. They fan is too large for the bearing/seal in the little water pump and they just don't last. Good thing they are cheap and easy to replace.

 

[TJBaker57]

I've been through so many water pumps I'm convinced they were not designed robustly enough. They fan is too large for the bearing/seal in the little water pump and they just don't last. Good thing they are cheap and easy to replace.

I wonder if the originals were better made. I just replaced mine at 284,xxx miles. I got it at 149,xxx miles.

 

[e-iowa-o]

I've been through so many water pumps I'm convinced they were not designed robustly enough. They fan is too large for the bearing/seal in the little water pump and they just don't last. Good thing they are cheap and easy to replace.

Ever had one squeal before failing?

 

[e-iowa-o]

I wonder if the originals were better made. I just replaced mine at 284,xxx miles. I got it at 149,xxx miles.

I'm sitting at 117k but it's still 17 yrs old.

 

[mrrsm]

The added Centrifugal Force at Higher RPM makes the rotating mass of the Heavy Tan Plastic Fan Blade Unit wobble violently at its outer edge. Thus, this gives it enough "Ooomph" to jerk that Steel Pulley Wobbling on Bad Bearings more impetus to move quite rapidly back and forth (or in and out, if you prefer) allowing the Serpentine Belt to skip along the pulley surface ...and Squeal like a Stuck Pig.

So while reproducing this phenomena at Idle might NOT be possible, it kind of adds to the symptom list of things that point right back at the Water Pump as being the cause and origin of this problem. Note also that the Chirping Sound gets magnified by that Pulley in its hollow inner cavity. If you strike it once its off the WP with a Tool ...it will Ring like a Bell.

IIANM You can probably find the ACDelco "Professional" Water Pump Kit using the Numbers from the images I added above over on Amazon for just about as much as the lesser known After-Market versions would cost. That ACDelco one was nicely manufactured up in Canada.

 

[Blckshdw]

Ever had one squeal before failing?

Mine had more of a screech than a squeal, and it was a short term symptom. Was halfway out of my neighborhood on the way to the store when it started, anytime I touched the gas there was this loud screech, but it would go away when I let off and coasted. Turned back around and went home (slowly! ) I didn't rev the RPMs when I shot this video, but the wobble of the fan was so obvious, I didn't need to.

 

[e-iowa-o]

lol

 

[gmcman]

When my water pump went bad, it sounded like a knock and gave me a moment of pause.

If this noise is a water pump, then why won't it make noise at 2500 RPM in park?

Something to try, and I would have this plan scoped out before you do. I would pull into a parking lot, remove the serpentine belt, then drive maybe a 1/4 mile getting it up to 50 MPH and see if the noise still persists. DON'T TRY TO DRIVE MORE THAN THAT WITH THE BELT OFF, since you no longer have coolant circulating, the engine will heat up very quickly.

What does your trans fluid look like? This noise seems to follow engine RPM under load and not any rotating driveline parts except maybe the transmission torque converter/ pump.

I hope it's not anything in the trans but this noise is new to me.

Edit to add: Is the belt too large? You can check by pulling over and wetting a pulley, it would likely sizzle the water on the pulley if the belt is slipping. Also, is the belt maybe rubbing on something or itself?

You seem to have a CEL, what are the codes?

 

[e-iowa-o]

Thanks for th input. I'm unable to touch it for the next couple days due to work. But will try running it with out th belt.. that should confirm the problem. I have squirted water on it and even PB Blaster on anything else moving. I know the belt is the correct length. I have it so the tensioner is in middle of range of motion

 

[gmcman]

I know the belt is the correct length

I'm not doubting you, but did this happen before the belt change? These belts are measured in millimeters, and I've bought belts at a parts store to later find that even though the tensioner was in range, it was still the wrong size.

That's not a common occurrence, but just food for thought.

Not knocking what @MRRSM said about the water pump....I sure hope that's the case. Just curious why it won't act up in park, engine hot, with the RPM's at 2500.

Be sure to check the check engine codes.

 

[TJBaker57]

I'm sitting at 117k but it's still 17 yrs old.

I was indeed tickled just now to conclude that my recently replaced water pump was in fact the factory original from 2001!! A little over 285 thousand miles. Might still have been in service had I not had a run in with a full sized 8 point deer at 65 mph back in January. Just checked it out with a dial indicator and there is a tiny measureable wobble in the shaft that may have contributed to the seal failure I had later on.

 

[Mooseman]

My thoughts on this. The noise doesn't sound like belt squeal. Because it stop as soon as you let off the gas, stopping sending power through the driveline, and it doesn't do it in park, I'm thinking something downstream of the flywheel like the torque converter, transmission, transfer case, u-joints, differential. Have you tried with the wheels jacked up and repeating? Does it disapear or lessen? Did you ensure it's in 2hi?

 

[e-iowa-o]

Oh God.. so many variables to ck.. lol. I can't look at anything till the weekend.

I'm not doubting you, but did this happen before the belt change? These belts are measured in millimeters, and I've bought belts at a parts store to later find that even though the tensioner was in range, it was still the wrong size.

That's not a common occurrence, but just food for thought.

Not knocking what @MRRSM said about the water pump....I sure hope that's the case. Just curious why it won't act up in park, engine hot, with the RPM's at 2500.

Be sure to check the check engine codes.

Yes. Happened before. Noise got gradually worse over course of few weeks. So it tried wetting belt but cldnt make significant change in th noise so replaced belt and tensioner. New belt was under tension and noise was a little less so I put a bit tighter belt on for good measure. Squealing was a bit worse before New belt (s) and tensioner. Noise was not reproducible in park before changing out these parts.

 

[gmcman]

You definitely don't need to change the length of the belt at any time, best to only use the factory recommended length.

Does the 04 use an air injection? If so, does it only flow air in drive?

 

[mrrsm]

The reason that the *Chirping* does not occur at Low RPM and Idle is because the Serpentine Belt TIGHTENS enormously when the rotation and torque on the Crankshaft-Harmonic Balancer Serpentine Pulley increases dramatically as the Engine RPM increases. :>)

 

[JayArr]

If all else fails look at the alignment of the belt. I once had a Blazer with a vortec engine that had belt squeel that I chased for years. I would change the belt and it would go away for 2-3 weeks and come back, Spray on belt dressing was good for a few days to a week. I changed all the idlers and it still came back. It would squeel when leaving the driveway cold and go away when warmed up.

One day I moved the power steering pulley in by 1/16" and it never came back. I'm guessing new belts had too much grip to slip but when they got older the misalignment meant that all the friction was on one side of the Vs in the belt and that wasn't enough to keep it from slipping.

 

[gmcman]

I changed an idler pulley on mine a while back, turned out it was just ever so slightly more offset and rubbed on the timing chain cover.

I also had a slight chirping noise but I swapped the new bearings into the old pulley and all was good.

 

[e-iowa-o]

Thanks everybody. I drove it today and for some reason the squeal was about 50% reduced. I'm gonna throw on a new water pump since it's fairly cheap an easy. The bell is very well polished and if I flex the fan it seems like I can get the shaft to flex just a little bit (1-2 mm). Nothing like Blckshdw's..

 

[TequilaWarrior]

Thanks everybody. I drove it today and for some reason the squeal was about 50% reduced. I'm gonna throw on a new water pump since it's fairly cheap an easy. The bell is very well polished and if I flex the fan it seems like I can get the shaft to flex just a little bit (1-2 mm). Nothing like Blckshdw's..

I virtually guarantee it's the WP. Mine squealed like hell before I changed it. Well, actually it squealed like hell for the return commute from work... and the shaft seal failed in the last half mile or so leaving a nice trail right into my garage and leaving me no options but to change it.

 

[Billdaman1]

Did anyone actually confirm what the solution was to the squealing issue on e-iowa-o's truck? My truck has identical symptoms, and will NOT Squeal in Park regardless of the RPM's, the truck must be moving. Interestingly it will squeal at low speeds but once below 8 MPH, no squealing. Mechanic stumped. I replaced Belt, Tensioner, Idler pulley just like e-iowa-o did (because its identical to belt squeal). e-iowa-o has apparently dropped off forum

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[Mooseman]

@e-iowa-o never came back to conclude this thread so no way to know.

If your noise is speed related and not directly engine speed, I'd suspect something else. I had a persistent squealing coming from a rear wheel and it wound up being a brake pad shim rubbing on the rotor however it was worse at low speed and would disappear at higher speed. Once I replaced the brakes, squeal gone.

 

[JayArr]

Could it be from the alternator and only appears when the alternator is loaded while the car is running.

Do you have a battery load tester like this?

Robot or human?

You could try clamping on and adding a heavy load while idling and if the squeel starts then you may be able to conclude that it's the alternator.

 

[Billdaman1]

Putting it in drive and against a steep curb while stepping on the brakes and flooring it… No sound what so ever. The truck MUST be moving for it to make the ”belt squeal nose “ that isn’t belt squeal because everything was replaced just like e-Iowa-o did. It’s absolutely coming from the right under hood side. Same sound he posted is plaguing my truck

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[budwich]

Did anyone actually confirm what the solution was to the squealing issue on e-iowa-o's truck? My truck has identical symptoms, and will NOT Squeal in Park regardless of the RPM's, the truck must be moving. Interestingly it will squeal at low speeds but once below 8 MPH, no squealing. Mechanic stumped. I replaced Belt, Tensioner, Idler pulley just like e-iowa-o did (because its identical to belt squeal). e-iowa-o has apparently dropped off forum

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I think near the "end", the OP was left with replacing (re-replacing) his water pump.... which might be the right direction at this point based on what you have replaced to date.

 

[Billdaman1]

I think near the "end", the OP was left with replacing (re-replacing) his water pump.... which might be the right direction at this point based on what you have replaced to date.

Agree, heading that direction. What a PITA. 3rd one.

 

[budwich]

hold it!!!! your third water pump.... and none of those solved the noise problem??? IF so, then its unlikely to be the problem. Are you doing this work yourself or is someone else doing it?. I would pull the belt and "feel" how things are to get some "baseline" of things.

My "water pump" suggestion was based on your initial reply of what you have done to date but your "list" seems a bit thin.

 

[Billdaman1]

What I meant was if I end up replacing the water pump as the root cause of this issue it would be the second time I replaced a water pump over the life of the truck . Thanks for the reply, I will be pulling the belt once I get it back.