2001 Mercedes-Benz C320

? Hello. Can you please tell me what might be wrong with my 2001 Mercedes-Benz C320, 3.2-liter V6 engine with 47200 miles on it? I am experiencing the following problems:

• On Idle, the engine makes a slight intermittent tapping noise that sounds like a sewing machine after driving for several minutes.

• The car has an an extremely noticeable acceleration delay and is very sluggish when accelerating from a low speed or stopped position (such as accelerating from a traffic signal or moving forward into traffic at a slow speed.)

• The car has a vibration when idle while stopped at traffic lights, and at times, feels as if the engine is about to shut off.

• All of the above problems are experienced after driving the car for several minutes at different times of the day, but usually occurs after the car has been parked for a short while.

Any information that you could provide would be much appreciated.