[capkirk123]

The serpentine belt on my V6 has always occasionally squeaked when it got wet, but it always went away quickly. However, last year, I decided to replace it as a preventative measure, and recently it has started squeaking non-stop. Belt conditioner just makes the problem worse, while chemical guys plastic conditioner will usually shut it up for a bit.

Typically this would be a bad tensioner, but mine seems fine, it doesn't vibrate at all with the engine running, and I have to put my back into it to get it to budge at all. Similarly, the idler pulleys spin smoothly when they're unloaded. I suppose it could be the alternator or A/C pulley, but the sound doesn't change when you turn on the A/C or radiator fans.

This leaves the 6 month old belt as the only thing that's changed. It was just the cheapest thing they had at Autozone, no idea what brand, the logo has faded already. Should I buy a nice OEM belt or something and try that?

 

[Hudouc]

Take the belt off and spin all the pulleys by hand first. I had a AC compressor coil rub against the AC pulley due to rust that did almost exactly what you said. If I drive through a bit of standing water, it'll squeak for a second or two and I'll see a voltage drop, but otherwise no noise.

 

[WiiMaster]

It was discovered that on Odysseys using the hydraulic tensioner, aftermarket belts were causing a noise on cold starts, and this went away using an OEM belt. This was determined to be because the aftermarket belts are considerably thinner than the OEM belt. It may be something similar here.

https://www.odyclub.com/threads/serpentine-belt-tensioner-rattle-vibration-solved.357584

 

[KW2004Accord]

Bando is OEM, many part places sell them. Belt manufactures do carry different quality belt lines.

 

[WiiMaster]

Belt manufactures do carry different quality belt lines.

And that is key. A Bando belt was tested in the thread I linked and was still found to be thinner.

 

[75Gremlin]

Bando is OEM, many part places sell them. Belt manufactures do carry different quality belt lines.

I have a Bando, no squeaks

 

[TX Accord]

I'm running a Dayco 5060840 from Rock Auto. I've never had problems with aftermarket belts or idler/tensioner pulleys but I had problems with every aftermarket belt tensioner I tried.

 

[capkirk123]

The tensioner is original and seems to be in perfectly good condition. Good idea to take the belt off and make sure everything spins freely. Also, the belt does seem to be thinner than the pulleys, there's a gap between the edge of the pulley and the edge of the belt.

 

[WiiMaster]

The tensioner is original and seems to be in perfectly good condition. Good idea to take the belt off and make sure everything spins freely. Also, the belt does seem to be thinner than the pulleys, there's a gap between the edge of the pulley and the edge of the belt.

That's not the direction you want to measure thickness. You want to measure the thickness from the grooved side to the smooth side of the belt. That's the kind of thickness difference that can cause a noise.

 

[75Gremlin]

The tensioner is original and seems to be in perfectly good condition. Good idea to take the belt off and make sure everything spins freely. Also, the belt does seem to be thinner than the pulleys, there's a gap between the edge of the pulley and the edge of the belt.

FYI
"a pulley bearing that lacks grease and is about to fail will spin more than one or two revolutions when spun by hand"

"Idler pulley doesn't spin as freely. Bad sign? new bearing is full of grease and means it will have resistance when cool. The way to actually test for a bad pulley is if it spins freely."

It's Counterintuitive when it comes to idler pulleys, a bearing that spins more freely in these is an indication that it is in the failure mode.

How many miles on the idler pulley? If over 200k miles a new bearing installed in the idler pulley will have less spin.

 

[capkirk123]

FYI
"a pulley bearing that lacks grease and is about to fail will spin more than one or two revolutions when spun by hand"

"Idler pulley doesn't spin as freely. Bad sign? new bearing is full of grease and means it will have resistance when cool. The way to actually test for a bad pulley is if it spins freely."

It's Counterintuitive when it comes to idler pulleys, a bearing that spins more freely in these is an indication that it is in the failure mode.

How many miles on the idler pulley? If over 200k miles a new bearing installed in the idler pulley will have less spin.

I mean it spins once if I spin it by hand, and it has no play at all. It feels like a brand new bearing.

 

[75Gremlin]

I mean it spins once if I spin it by hand, and it has no play at all. It feels like a brand new bearing.

So did mine. But the difference after I installed a new bearing was significant. Over time the grease "dries out" and is otherwise compromised. But this is likely not the cause of the squeak.

 

[capkirk123]

Alright, took the belt off, spun everything by hand, everything feels fine. The A/C pulley in particular spins very well, it's not rubbing on anything.

Just for good measure, I took the tensioner pulleys off, popped the covers off, cleaned it out with brakleen, and regreased it with lithium grease. It's stiffer now at least.

Anyway, no difference. Still squeaks. Loosening the tensioner with a wrench, no difference until it gets so loose the belt starts slipping and vibrating. Tightening the tensioner, the squealing gets louder. I don't think the tensioner is to blame, it certainly seems to be tensioning correctly.

Anyway, applying plastic conditioner to the belt, applying it to the outside does nothing, applying it to the inside quiets it down for a bit, which all but confirms it as not the idler pulleys. I think I can say it's either the belt or one of the accessories at this point. I really don't want to replace the accessories, so I guess the next step is OEM belt unless anyone has a better idea.

 

[capkirk123]

Oh, and FWIW, the parts store belt feels very rubbery and even slightly sticky, while whatever belt was on it originally had a more leathery texture.

 

[KW2004Accord]

Oh, and FWIW, the parts store belt feels very rubbery and even slightly sticky, while whatever belt was on it originally had a more leathery texture.

American made & higher quality belts are made with epdm rubber which is resistant to oil / gas chemicals. The cheaper belts from China can be fiberglass construction.

 

[visionguru]

It was discovered that on Odysseys using the hydraulic tensioner, aftermarket belts were causing a noise on cold starts, and this went away using an OEM belt. This was determined to be because the aftermarket belts are considerably thinner than the OEM belt. It may be something similar here.

https://www.odyclub.com/threads/serpentine-belt-tensioner-rattle-vibration-solved.357584

On V6, OEM is Mitsuboshi. I have Bando, no issues. The tensioner takes away any slack of the belt, slight difference in thickness or length is nothing.

Belt noise can have many causes, such as fluid contamination, pulley/alignment problem, belt stretching.... When a mechanic did my timing belt, he installed my old OEM serpentine belt in a different direction, the belt noise was horrible; I reversed it and it was quiet. It a very sensitive part, but cheap. My Bando was less than $20.

OP, get a new belt and go from there.

 

[capkirk123]

On V6, OEM is Mitsuboshi. I have Bando, no issues. The tensioner takes away any slack of the belt, slight difference in thickness or length is nothing.

Belt noise can have many causes, such as fluid contamination, pulley/alignment problem, belt stretching.... When a mechanic did my timing belt, he installed my old OEM serpentine belt in a different direction, the belt noise was horrible; I reversed it and it was quiet. It a very sensitive part, but cheap. My Bando was less than $20.

OP, get a new belt and go from there.

Actually, flip the belt, I like that. The belt sits way closer to the edge of idler pulleys than the old belt. Cheaper than a new belt too. I'll try that in the morning.

 

[capkirk123]

Followup on this. I never found a satisfactory way to stop the belt squeaking, but it mostly went away with warmer and dryer weather. However, I just took my crank pulley off, and it fell apart at the rubber damper. It's possible the squeaky belt was a symptom of the crankshaft pulley starting to fail, I'll see if the squeak still shows up with a new one.

 

[TX Accord]

Bando is OEM, many part places sell them. Belt manufactures do carry different quality belt lines.

Bando is OEM, many part places sell them. Belt manufactures do carry different quality belt lines.

This is happening in multiple threads

 

[capkirk123]

View attachment 566957
Followup on this. I never found a satisfactory way to stop the belt squeaking, but it mostly went away with warmer and dryer weather. However, I just took my crank pulley off, and it fell apart at the rubber damper. It's possible the squeaky belt was a symptom of the crankshaft pulley starting to fail, I'll see if the squeak still shows up with a new one.

A new harmonic damper/crank pulley does in fact seem to have stopped the squeaking. The belt was innocent all along.