96 SL320 Problem?

[bwheitman]

I have had my 96 SL320 for 2 months now. I have noticed that while at idle with no load, tranny in park or nuetral that the RPMs' fluctuate slightly. My 92 300sd diesel doesn't do this, but the 320 gasoline engine does. I have not driven a gas car in awhile and don't know if this is normal. The car is fine otherwise, when you have it in drive at a light is is perfectly smooth, acceleration is smooth, I don't notice any malfunctions. When I got the car I replaced the plugs, the belt, anti-freeze, oil and filter, transmission fluid and filter, gear oil in the rear, and brake fluid. I repaired the rear view mirror (I learned how to with my 140) and when I got done the car would not run. It went into limp mode. (strange huh) The engine light came on. Anyhow I turned the car off and then re-started, it was fine and after a few more starts the engine light went out. Any ideas on what I should check? Maybe I am just being paranoid.. ha ha..
Brian

[elau]

How much fluctuation are you talking about? Sounds like you have done almost everything needed for a used car. I would check if there is a small vacuum leak.

[bwheitman]

You know that sound like it could be the problem, I get the loud vacuum pump every morning when I start my car, I bet there could be a leak somewhere. I am replacing my valve cover gasket this weekend, while I am doing that I will check all my vacuum lines. Thanks for the suggestion!