I just noticed this happening when I punch the pedal down quickly. I get a loud squelching sound from the alternator area. This only happens if I punch the pedal quickly though not always. I had my wife hit the gas a few times in park while I listened with the hood up and it's definitely coming from the alternator area. I'm new at all this stuff but I assume a slipping belt wouldn't create this squelching sound? (Belt is tight) Just trying to cover my bases...again this only happens mostly when I punch the pedal quickly rather than gradually pushing the pedal down. Driving under cruising conditions creates no sounds from the alternator area.

Thank you for any ideas.

1969 Cutlass S 350 2-barrel

 

Well it does sound like it's a slipping belt. Are you sure it's the correct belt? Also what shape is the belt any glaze on the sides where it rests in the pulley?

 

Sounds like a loose belt.

How old are your belts?

How tight is "tight?"

- Eric

 

I guess I am not sure what you mean by a squelching sound but you could definitely have a slipping belt esp. if it only happens under heavy load. It is a pretty cheap and simple fix so that is where I would start. Please let us know if you need any help and if that fixes it.

 

Thank you I'll try the belt. It doesn't look too bad but there is some wear so I'll give it a go later this week. I'm pretty sure I can do it myself after watching a couple of videos but if I run into any trouble I'll fire questions in here. Thank you everyone from a real greenhorn

 

You should be able to get about ½" movement at the longest span of the belt with firm, moderate finger pressure (not hard pressure) in the middle of the span.

- Eric

 

also check the groves in the pulley,if it is worn out the belt will ride in bottom of pulley and slip.belt should only contact the sides of the pulley grove.flat side of belt should be just about flush with top of grove.not deep down into pulley.good luck.

 

Good news everyone...replaced the alt belt with a good quality gates and no more loud squelching when the pedal is punched. Thanx everyone you were all spot on

Tightened belt to water pump while I was at it as well

 

i experience this kind of problem. if the noise goes away in a moment, or so, it is probably a loose belt. If it is not too loose it will go away after the battery has recharged.A bad alternator bearing can also make a screeching sound but by the time a bearing gets to that point one had better be getting it fixed pronto. hope that this also helps to solve your problem.

 

Hard, glazed, or ill-fitting belts can slip even when tight. Been there done that...
Gates is a good choice.

 

And remember, a new belt will stretch after it gets a few miles on it, and will probably need retightening, or it will start to slip also and give you the same sound. Nothing you did incorrectly, Just normal.