2002 Protege5 - Belt Squeak won't go away - tried everything(?)

[btappan]

2002 Mazda Protege 5. Had a lot of issues with belt squeak over the years ... not sure what to do / try next. Here's the history:

December 2012 (79,000 miles): Belts squeaking - had them tensioned / tightened - and belt dressing applied. All good / no squeaks.
March 2013 (81,000 miles): Did the timing / drive belt replacement (along with water pump, etc). Just FYI (no squeak when I took it in for this).
November 2014 (100,000 miles): Belts squeaking - had them tightened again. All good / no squeaks.
December 2014 (101,000 miles): Belts squeaking - mechanic removed all belts - and cleaned all of the pulleys / wheels they come in contact with. All good / no squeaks.
December 2015 (114,000 miles): Belts squeaking again - not sure what to do at this point?

I live in the Seattle area / car is kept outside. This problem always seems to come around when the weather gets cold / get a lot of rain (and more noticeable when fan kicks on).

Not sure if I should apply some belt dressing - or take to a mechanic to re-tighten everything once more?

 

[TheSwapnessMonster]

You never replaced the belts? The belts could be cracked and worn. In general, rubber materials degrade over time due to repeated heat loading and stretching cycles.

 

[btappan]

I had all the belts (timing + accessory / drive) replaced at 81,000 miles.

 

[MrGiggles]

I would consider it normal for these belts to be tightened at least yearly. They carry a lot of load for such a tiny belt, and really need to be tight to not squeal. I normally check tension every two oil changes. Have your mechanic check the tension again, they probably just need tightened a hair from typical stretch and belt wear.

Do you have all your splash shields in place? The alternator hangs pretty low, and without the splash guard the belt can get wet. I've been battling this one myself, PO tossed them.

 

[Maroon]

I have always had this issue on my car. Tightening the belt more than a typical serpentine belt definitely got rid of a lot of noise. And I have had no failure of any of the accessories driven by the belt due over tightening.

I still get squeal when I turn on accessories at idle (headlights, fan, or defrost). The only way to get it to stop is to shut off the accessory, bring up the idle, and then turn the accessory back on. There is definitely something wrong with the electrical system on these cars, and I think it may be that the alternator is underpowered. I think the initial draw from the accessory being turned on breaks static friction between the belt and alternator, and that is causing the squeal. Many owners complain of dimming headlights, and I think that's also a symptom of an underpowered alternator.

Or maybe the serpentine belt system is just poorly designed as suggested above.

 

[MadOnion]

I had to tighten the belts on my p5 tighter then a nun till they would stop making noise. I replaced them and then had to tighten them up and run it and then tighten them and run it and then tighten them. Eventually they stopped and they are good now, far tighter then I have ever made the belts on my cars before.

I agree with the underpowered alt though its winter here and at idle my lights dim the blower slows and the wipers all but stop.

 

[pcb]

Be careful with over tightening. I had my mechanic over tighten my alternator belt and wrecked the alternator bearing... Twice..

The alternator was covered under warranty but not the $180 labor each time.
(that was before I started doing my own work)
New belts can make a huge difference and aren't too expensive.

Apparently once a belt squeals too much it becomes "glazed" and starts to slip really easy.

I good rule of thumb is to reach in and try to twist the belt. If you can turn it upside down it's too loose... If you can't turn it sideways it's too tight.

We have a very small pulley on our alternator with very little belt wrapped around it... It was designed and built to squeal like a piggy...

 

[MrGiggles]

Be careful with over tightening. I had my mechanic over tighten my alternator belt and wrecked the alternator bearing... Twice..

The alternator was covered under warranty but not the $180 labor each time.
(that was before I started doing my own work)
New belts can make a huge difference and aren't too expensive.

Apparently once a belt squeals too much it becomes "glazed" and starts to slip really easy.

I good rule of thumb is to reach in and try to twist the belt. If you can turn it upside down it's too loose... If you can't turn it sideways it's too tight.

We have a very small pulley on our alternator with very little belt wrapped around it... It was designed and built to squeal like a piggy...

It's a very silly design for an 80 amp alternator. The belts on most cars out there are 1 or 2 ribs wider for a similar alternator.

 

[Natey]

My friend had an endlessly squealing belt too. He replaced every belt, only to have the noise keep resurfacing. It ended up being the pulley for the waterpump. At some point it got off kilter by a little bit and no matter what you did it would always make that belt squeal eventually. Once he replaced the water pump, the noise is gone for good.
Check all pulleys.

Temporary old school fix: Plain old hairspray will make the belts sticky and less likely to slip. Something like Aquanet

 

[P-Funk!]

If the belts slip for a while - they get glazed and must be replaced.

Check and tighten tension at the first sign of squealing. Check/tighten BOTH belts.

 

[pcb]

We have a very small pulley on our alternator with very little belt wrapped around it... It was designed and built to squeal like a piggy...

It's a very silly design for an 80 amp alternator. The belts on most cars out there are 1 or 2 ribs wider for a similar alternator.

They should have added an idler or tensioner pulley to wrap the belt around the alternator pulley better...

 

[P5freek]

How do the tension adjusters work? I changed my belts the squeal like mad. I cant get the adjusters to work.

 

[MrGiggles]

Loosen the upper and lower pinch bolts, then turn the 10mm adjuster bolt clockwise. I pull the cruise control actuator and do the alternator from above.