What all has to be replaced when the crankshaft pulley? falls off

Mary,

This type of problem is best checked by a trusted mechanic. I doubt you'd hear squealing noises from the crankshaft or harmonic balancer; but it is likely to be heard from a belt tensioner pulley, water pump (or other belt-driven devices under the hood - such as the alternator, power steering pump, etc.). A loose or slipping belt can also cause this noise.

Spraying WD-40 on the source of the squeal may quiet the sound - but not solve the problem that is causing it. By simply masking the problem with WD-40 instead of fixing it - you run the risk of the squealing part failing catastrophically - probably at the least desirable place and time.

For your own safety and convenience, have this problem checked and repaired properly.

Good luck!

Check the fluids first. Belt squealing isn't the distributor. If the fluids are good, remove the belt and start it. Knock goes away, find the pulley that locked up. Replace it with the belt. My guess would be the A/C compressor.

with car off and keys in pocket open hood and check all pulleys and components something not turning possible seized such as idler pulley alternator noise is belt being dragged over something not turning

Replace the crank pulley before it costs you an arm and a leg. It has caused this problem. don-ohio

Belt tensioner problem or bad belt

You need to replace a pulley.

I also have an 04 Sorento and LOVE it. I live in northern indiana where it is super cold in the winters and just this year my truck started squealing when temps got low and when the heat is on. My dad has also changed the belts, even though they looked fine. that didn't fix the problem. I was searchng for some answers and it seems that many people are having this same issue with sorentos. Its super annoying and like you sid embarassing! I love my truck, but HATE this sound! if you find anything else out, please post! Thanks!

Your vibration damper may be going bad!
It sounds like a belt problem....but isnt load sensitive right? Yeah....that's what they sound like. Especially the part where they squeal on start up.

Have the tensioner replaced too just in case.

You didn't mention the alternator, power steering pump, or water pump. In fact, any pulley other than the crankshaft one can have a bad bearing or dry seal. Remove the belt and spin each pulley while listening for any rough noise or squeal. If it was the crankshaft, it might be time to check the oil. Start the engine with the belt off to see if it does squeal. Make sure the noise isn't coming from the radiator fan(s).

Check the pulley alignment if they are not aligned they eat the belts, if they have the ribs to sharp they willcut thru the belts, Inspect the crankshaft pulley if it turns too freely it may be loose from vibration rubber, replace it.