MB doc,
I have a similar problem with my 350SD. The A/C takes about 5 min. to kick on once the car is started and it shuts off frequently. When the A/C actually is blowing it makes a noise that sounds like the engine is nocking but it stops when I shut off the A/C. What could this be and if it is a vacuum leak what is the best way to find and fix it.
Thanks for the help!!!!!!