Hey guys,

When my E220C is in gear, the idle drops down quite a bit. Normally it idles a bit under the 10 mark (so, 850 or so rpm) but when in D or R it drops down.
Transmission was flushed, same problem.
I don't remember this always being like that. The rpms drop so low that even the oil pressure goes below 3 (if in P, it stays at 3).
People have told me this is normal, but I am 95% sure the car used to idle higher before, as I remember the oil pressure would NEVER budge from 3.

A pic of the tachometer in D: