My car also idles too high (just sits around 1500 rpm) and when calling my mechanic yesterday, the long distance diagnosis was a faulty idle control valve.

Reading through this post I might not need to install a new
valve - providing the scenario described in this post would also
apply to my M103 engine ('89 300CE).

Any potion this forum can mix up to combat my newly gained headache'?

If a new valve is indeed required, would any of you have the
corresponding part number and an idea what this may cost me
to fix?

Thanks!