Screeching sound when LEO motor is trying to start.

sound like engine timing could be off due to worn timing belt or timing chain.

indicates that the starter motor is stuck in the ring gear
possibly faulty starter relay or starter solenoid
pull the starter as the pinion over ride clutch is probably damaged ( noise ) and have the start circuit and relay checked
have the starter bench tested for serviceability by an accredited auto electrician

Sir, I think you need diagnostic this car. I think just screeching sound, but maybe hide the big problem. http://www.chinasinoy.com/search/?q=mercedes+

Sounds like your blower fan motor is getting bad bearings. They are usually just an oil soaked bronze which will start to "gall" after the oil dries up. Dusty conditions also have an adverse effect. Find the blower motor and remove it (usually 3 or 4 screws) and spray the motor shaft where it exits the to the fan with a product called "tri-flon" . it will stink for a while, but will solve the problem.

If the noise comes from the starter motor/flywheel area it is probably is a faulty drive clutch in the starter motor.
A replacement starter motor may be required.

actually this sound to me as to be the kick out bearing on the starter itself. after it has been on the car for a few years they tend to get moisture into the outer bearing on the starter this washes the grease out over time and it makes a horrible growling, screeching, or rubbing noise after starting. this starter should be replaced in the near future if not it will seize up and just click when trying to start the car....... I hope this has been helpful.

You have have too tight or too loose of belts, check the tension of the belts. You want to be able to have about 1/2 inch give on the belt

sounds like the motor on your ac is frozen up

It may just need to be adjusted (it sounds like it's too loose). If the belt isn't cracked or frayed, you should just have it tightened up a bit . If there are signs it is worn (cracked frayed) replace it.