sunrat

Hey I have a quick question for you, my car seems to idle in somewhere near the 1100rpm range when i start the car up and leave it in park or neutral. when i put it in drive it is near 7-800 level mark. How damaging can this get for my car? Also, is there a way i can adjust it? This all seemed to happen after i cleaned my throttle body, thanks for your help guys.

cil254

It is normal to rev higher when you just started it (warm up), but then it should drop by itself.

mctwin2kman

Even my W203 does this when parked over night or long enough for the engine to cool engough. Last about 30-60 seconds or so if I actually wait for it! It for warmup and to heat the Cats faster for emmissions purposes!

sunrat

what? i mean it stays at 1100 rpm all the way even after like 10 minutes of it sitting there. 800 or so rpm when it is in drive, is that normal?

mctwin2kman

Normal in Drive yes! Not sure what the 280's normal idle is though! My W203 idles at about 900 RPM in Nuetral, since it is a 6 speed that is all I can really give you! 1100 may just be a sensor going bad, like a temp one that tells the ECU engine temp to adjust idle! On my 190E it is called the Water Temp Sensor and it feeds the CIS-E controller the engine temp to control idle for cold starts! But my W203 idles at about 1100 until the engine temp gets somewhere over 40 degrees! Then it drops to 900. If just idling that could take 5-10 minutes time!