Hey guys,


So my 560 SEL has always had a high idle (950-1000) when in park or neutral, and relatively normal (650-700) in gear.

I drive her this morning, and it does its usual routine, high idle and fine in gear; but I let it sit for I dunno, an hour after driving through New Haven to drop my brother off at school (40 minute commute, tops), and I start back up, it makes this weird gurgling noise, and only idles to 550-600.

I immediately thought something was wrong, so I revved, and it died shortly after.

I start her back up again, and it idles to 550-650-ish. It runs smoothly and quietly, with a little hesitation when I first step on the pedal.

Is there any explanation? I haven't changed anything other than the fact I switched from Mobil gasoline to Sunoco gasoline 3 tanks ago. I put 7.148 gallons of Mobil in this morning in a rush.

It scares me because I'm so used to a high idle that the regular idle makes me question...

P.S. I do have a major tune-up (timing, rotor, cap, sparks, oil, the likes) coming up; I guess I can ask my indy what he thinks (although he doesn't seem to like working on fixing high idles in W126's in general )



Thanks guys,


Carlen

P.P.S Sorry I wasn't able to hunt the issue, I really wanted to help everyone with a high idlin' 560; they all do it...

__________________
_______________________________________________

1987 560SEL (210,000 miles)

Alright,


So I've narrowed down this anomaly.

When I went to start the car early this morning, it idled at 750, revving itself between 700 and 800 rhythmically.

I drove it and came back, and it idled at 950 at idle when I parked.

So much for riding on the correct idle speed...


But then I drove out again, and didn't start the car for exactly 1 hour and 20 minutes. It idled to 550, and stayed there. No issues, no roughness. Perfect.


It's never done this before; I'm gonna keep at it and see if I can make any headway.



-Carlen

__________________
_______________________________________________

1987 560SEL (210,000 miles)

this sounds like an Idle Control Valve issue to me, as a major tune has just been done. The thing is..to get to ICV you have to take a bunch of **** off simply too get it...I would bet if you decide to take the ICV off and clean it up and put it back on your problem would be solved.....