Terrible Squeeking from serpentine belt

The high pitched sound comes and goes when driving. Lubricated the belt, did nothing. In addition to this sound the car wont start after a long period of not running. I have to jump start it and it will work for awhile. Went to Schucks. They heard a “metal on metal” sound from the belt area and suggested replacing the water pump. They checked the voltage of both the battery and alternator which were normal. They said electric problem and to see a mechanic about it. I bought a new water pump. Should I replace the old one? Opinions please.

Water pump, power steering pump, alternator or idler. Any of these (or anything else driven by the belt)could be causing your noise. You picked one of the more difficult to replace.

Does the water pump leak? There’s a weep hole at the bottom to let you know the bearing and/or seal is failing. Look at your new pump for reference. If there’s no indication of a leak there’s no reason to believe the water pump is your noise.

Troubleshoot by holding a long thin wooden or metal stick to your ear and (VERY CAREFULLY) touching it to various locations to isolate your noise. Otherwise you’re going to just throw parts at it until you accidentally find the right one.

The statement "lubricated the belt concers me. What product did you use. I have never “dressed” a serpentine belt with any product. Why would a metal on metal sound mean replace the water pump? Could you easily move the water pump pulley up and down? (as if the bearing was bad)Any way to take the belt off and turn the pulley by hand (checking for roughness or play) no metal shavings seen any where? Is it leaking coolant?

Is this post on the forum 3 times? This post did not identify car other post said it was a 83. Both about a guy who went to Schucks with a metal on metal sound. Gets confusing

I agree with oldschool about this lubricating the belt business. It’s not necessary and should never be done IMHO.
Have you considered the possibility of an idler or tensioner pulley bearing boing bad? A questionable belt should be replaced and the old belt can be carried as a standby for emergencies.

Why not remove the belt and rotate things by hand and see if it can be determined what is causing what is an apparent grinding sound.
As to not starting, maybe a slipping serpentine belt is not allowing the alternator to keep the battery up.

What kind of car and how many miles?

I too have never had any luck with belt conditioners. It’s a lot easier just to pop a new belt on. When you get the old one off, that’s when I had check all the pulleys. You can tell pretty easily when you turn each pulley by hand if there is a loose bearing or metal to metal. Needless to say, if you can’t turn one, it has a problem.

when looking for problems i try to follow the cheapest first theory.

in this case, the serpentine belt is cheapest followed by the tensioner pulley, idler pulley (if it has one on an unknown engine) and then the pumps and alternator and AC compressor.

the belt and tensioners seems the first place to look.

What vehicle and engine?.

I hope you don’t mind if I just follow up on this thread. I have a 95 Infiniti G20. I just had the alternator belt changed (it was working fine, but mechanic said it was old and cracking) over the weekend, and the car started to have “terrible squeeking” sound. I called the mechanics and was told that the tensioner needs to be replaced. My question is: “If my alternator belt was working fine (even it was just old), doesn’t it mean the tensioner was also okay?”

Thank you in advance.