My Metro 1.0L (no A/C) will squeal VERY loudly when it is cold, eventually goes away after car is driven awhile. Direct relation between noise volume and accelerator depression/load on the engine. Thought this was a belt issue, but have replaced it twice without results. Wondering whether to replace the alternator next, but wanted to search and ask on this useful forum first...

thanks for any ideas...

My Metro 1.0L (no A/C) will squeal VERY loudly when it is cold, eventually goes away after car is driven awhile. Direct relation between noise volume and accelerator depression/load on the engine. Thought this was a belt issue, but have replaced it twice without results. Wondering whether to replace the alternator next, but wanted to search and ask on this useful forum first...


thanks for any ideas...

Interesting. Are there any other signs of things not working right? Is the engine temp staying normal? Is the charging system working ok? Are you sure the belt tension is correct? Did the noise stop when you replaced the belt and them come back or did the belt change not help at all?

This only occurs under load (drving)? Or can you have it in park and throttle it a bit to the same effect?

Thanks for the replies!


The car drives, and reports as-if everything is fine despite the ear-piercing squeals; temp and charging stays normal. I’ve played with the belt tension, ranging from far-too-loose to far-too-tight. New belts didn’t help, even for a short time.

The effect is the same whether in neutral (5sp) or driving in gear, although in gear it may be a bit louder. Squeal dies away at idle, and eventually goes away completely after about 2 – 5 minutes of idling or driving.

A friend poured water on the belt while revved up, but was surprised it didn’t stop the squealing… and suggested it could be a bad bearing in the alternator or water pump??? We’re just guessing at this point…

quick test ..... remove one belt at a time and check for changes.

there's a bearing in the belt tensioner for ac too. replaced mine a while ago.

just one belt, no A/C...

just one belt, no A/C...


Still a quick test by removing the belt will narrow down the alternator bearing being questionable. It could also be the tensioner bearing. Can you physically turn each pulley, and feel any type of roughness, or resistance?

Isolate where the noise is coming from by using a long screw driver as a stethescope. Carefully probe the running engine with the handle placed up against your ear and the business end touching near suspect components. Don't touch any rotating components! It's amazing how well this works.

"far too tight" is usually not tight enough for a Metro belt, it needs to be "insanely tight". I've heard of people who tried multiple different belts and a Goodyear Gatorback fixed it.

The gatorbacks from goodyear are the best belts around hands down.

I'd just like to also add: Be sure you have all three (3) mounting bolts installed for your alternator, and that they are all snug. A lot of times guys will be running minus the third one on the rear bottom of the alternator, causing the alt pulley to fall out of plane with the rest of the engine. Which of course, can lead to squeel.

Love the title btw... 'shreiks of the damned'

-MechanicMatt

You might also spray the pulleys all down with starting fluid and this will clean them up, without leaving residue. Carb cleaner works good too.