Belt Noise when starting car

you need to tighten your belts

Belt may be slipping. Try some belt dressing.

drive belts.lights increase your alternator's turning resistance a loose belt will slip and squeal

The lost acceleration is of major concern. Maybe you have lost your water pump. It would work great for a few miles when you start out and then gradually heat up and loose performance. The fluid would eventually boil over? Maybe a bearing on the camshaft is expressing it's discontent and causing extra load for the engine to overcome. Try to determine where the noise is coming from.
The serpentine belt connects the alternator, water pump, power steering, front timing pulley, fan, and front timing pulley. All these components generate a parasitic load on your engine. If the engine has to work harder because of increased load it could be any of these components. I'd definitely check the water pump listening for noise while running. Look for obvious things related to the belt and its' components.
Check the serpentine belt for wear. May indicate pulley misalignment or wear. There exists two idler pulleys that have small bearings that wear out and squealing noises. Check those for wobble with the tension off the belt. They are pretty cheap so replace them if any concern at all.
Power steering pumps cavitate and make a high pitch gear whining sound if fluids are low or gears warn of. Check the fluid and top off to the correct level.
Best wishes,
TF

sounds like it just needs a oil & filter change ?
check engine oil level!
smell it to see if its burnt
or is dirty [tarnished or black]
or gritty between your fingers?
it could be noisy tappets or lifters!
change your mechanic as its got absolutely nothing to do with the belts!
im truly amazed at the amount of rip offs in the auto industry in the US!
Cheers Rob.

Had the same issue and it turned out to be the balancer. Not too difficult to fix any questions or advice, I am happy to help you. Justlet me know. Good luck

this sounds like your belt is loose or the belt tensioner bearing is bad

It sounds like your power steering pump as you said, but I would start with changing the main drive belt. I have come across this same problem before. If you change out the belt and you still have this problem, remove the belt and start the engine. Turn the wheels left and right and listen for the noise. If the noise is gone then put the belt back on and check again. If the noise comes back then you have a component problem. I have seen the belt tensioner to make noises as you describe. I hope this helps you. Let me know if this is helpful to you.

The noise is most likely the serpentine belt. Check it's condition and that of the belt tensioner. It sounds like the belt is slipping, causing the squealing noise u describe. As the belt warms up, it's getting a better 'grip' and the noise stops. Turning on the heat also turns on the a/c in newer cars, this added drag on the belt (one more component to turn, the a/c compressor) would explain why it happens when u turn on the heat. Is the belt original? If yes, it's time to change it, and check the belt tensioner to make sure it's doing it's job of keeping the belt snug on all the pulleys. Let me know how u make out.

possibly belt is slipping old and worn out