Car ran well for the first two weeks- now that I write this I wonder if there is a connection that after the AC was repaired the trouble started? Though the vehicle stalls whether AC is on or not.
Then a head gasket was replaced because oil was in coolant. I had believed that since the complaint was stalling that a full diagnostic was performed- so if the head gasket was replaced, then that is what was wrong.
After this stalling was more frequent and wild fluctuations of tachometer from Park to Reverse and from Park to Drive (interesting no problem when Drive to Park or Reverse to Park).
MAS replaced. AFter reading lots of posts here about stalling, I did ask dealer if things like clogged throttle, air/fuel mix, fuel relay or idle control were (the less expensive) culprits. He said know, so again I believed they must have checked all these items.
Vehicle was fine day one, day two on the second trip of the day- vehicle seems to be okay on first trip of day, not as errative tach fluctuation more that it dips when into R or D but on the way the jump is only up to about 10- and the swing down is slower.
When the vehicle is in its throws, I would not call it a miss, but something just doesn't feel right- other times the idle, acceleration etc. are fine. Even if the car does not stall, there are inconsistent times that there is a lurch and a hesitation while on the brake.
I also notice anecdotally that the vehicle consistently 'upshifts'. I chalked my concern up to lack of experience with an automatic, but to note, sometimes there is a long drag and the car kicks into I guess it is second, other times with the same accelerator pressure it goes through two-three gears. I find on the highway you don't feel a 'downshift' at highway speeds and I find myself not controlling the speed- but again this could be because I am a stick shift driver and I am not used to using brakes- but I would have thought any vehicle's speed can be controlled via accelerator.
Mailman just delivered "How to Repair and Maintain a Mercedes Benz" thought it would help me find the parts everyone talks about here- still not sure where this idle adjustment is- not that I would touch it, just want to see if it is set to where is should be- but then again if it weren't wouldn't the stall or inconsistent idle happen all the time?
And should I call the dealer back who replaced this MAS and tell him car still stalls- or will that cost me more money? I don't understand the repair 'guarantee' do they only guarantee that repair even if it does not fix the car and then charge for another item or would I be credited for that cost when it is determined what is wrong?