High Pitch Sound When Cold/Other Question
 

1. I have a 1978 300D. When I first start the car and drive up to about 25mph I hear a very high pitch squealing sound coming from the front of car. After that the sound goes away. What could this be?

2. I'm going to replace the front and rear flex discs on the car. Would this improve power?

3. When I turn from a stop sometimes the engine revs very high (but I'm going that fast) then the engine revs slow down after I'm done with the turn. What could this be?

Thanks for your help