I just recently purchased a 2006 R500 with 42,000 miles. I am a first time MB owner and have a few questions regarding the car:

1)I have had the car for 10 days and am now noticing that my RPMs at idle are around 600. I am almost positive that on day 1 they read around 1000. What should the RPMs be? I am also noticing that the engine is running a little ruff. I can feel a vibration on the gas pedal. Is this normal?

2)Should I bring it to a certified MB dealer to have it checked out?

Thanks in advance for your responces!

See my thread after you read this, anyway my '08 R350 basically the same motor just short two cylinders had a rough idle when stopped at a light idling. I could feel a subtle vibration too. Anyway, my car has 35K miles but had done this ever since we had it with 25K miles. My car is currently at Mercedes awaiting a new cylinder head due to a stuck or bad valve. I hope this helps, I'm not happy about it but glad I have the CPO warranty and that Mercedes has taken care of me.