Low idle in gear
 

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:
http://www.benzworld.org/forums/imag.../wol_error.gif
http://i26.photobucket.com/albums/c1...3/DSC00029.jpg

Bump
Anyone know?

It feels like the transmission or torque converter is maybe engaging too much at idle and is bringing the revs down via drag. Is this possible?

That's completely normal behavior in my 2.6L 124. After all, putting the transmission in gear puts a load on the engine. You'd expect it to bring the rpm down a bit.

I am pretty certain this is not how it used to be.
The revs drop so low that the oil pressure goes lower than 3. I have never before seen the pressure below 3

Spetz, your idle speed in gear is normal. Typically the oil pressure drops to between 1 and 2 bar when the engine is idling around 600rpm. Each bar is approximately 15psi so unless the oil pressure would drop to near 0 things are fine ... no reason to worry.

My Idle RPM go from 850 to just over 500 when in gear. Oil pressure when hot can get as low as .5 bar. I was a little worried at first, untill I read the procedure for setting idle speed.

I did notice that on hot days after a lot of driving my oil pressure dropped.
The lowest I have seen it is somewhere around 2.6 and I got really worried, but as soon as I put it into N it went back to 3.

Guys, maybe I am stubborn or something, but I am convinced this is not how it used to be.
Am I wrong? Do I just remember it differently?
Please keep in mind this car was owned since brand new and 16 years later I notice this??? Albeit, I was 11 when the car was bought.

Back to 3 bar in N??? That's something there, when HOT (80*C) mine idles around 850 in N with an oil pressure around 1.5. If you're shooting up to 3 there could be some blockage in an oil passage somewhere. Not trying to panick you, but it's indicative..in a V8 at least.

It's been like that since brand new (always on 3)
And we have owned other E220, 210 E240, and been in other Mercs which have all been at roughly 3 when idling

Hmm... Ok.. I'm not too knowledgable about the newer ones, have had only exp with the older stuff.

Same for W124.032 - 1995 E320
 

Oil pressure is in 3 range all the time, never going down.

Suspect is sending unit or stuck valve in the oil pump.
Idle is purrfect normal for hot weather

This is normal.