YesItsAGTR

Hey all I have a 2009 E350 amg 148k miles
I just basically replaced everything for service C
I bought the car about 2 or 3 weeks now didn't drive it until I got my maintenance stuff in. When I drive on all gears no matter which one the rpms non stop will jump just a little continuously non stop when accelerating. The car idles perfectly. I took it to the mechanic that specializes in mercedes he told me just by driving it he thinks it's coolant that is getting into the transmission. Which from reading other forums people get a jerk or transmission shift hard, Mine is different symptom idles fine, doesn't shift hard, just rpms go up and down when acceleration but it still gets up to speed. What bothers me is he says he doesn't notice the rpms lol when i told him while pressing gas look at the rpms and also you can feel it. Also I told him when you start the car look at the motor it looks like it has a hiccup everyonce in a while. Any other idea's prior to my ownership car sat for a year not driven. I put new spark plugs .8mm gap, all filters, full engine flush 2 times, gas cleaner and injector cleaner from liqui moly.

CaliBenzDriver

sounds like you maybe dealing with misfires....

Get an iCarsoft scanner to retrieve your list of faults plus read live ECU LTFT bank1+2.

YesItsAGTR

Ill ask the mechanic who has it I thought it was misfire. He supposedly been doing this 44 years he has alot of mercedes cars but I don't think he even bother checking. I even sent him pictures of something I found that the outside cover wire was ripped but no wire ripped and it goes into the catalytic converter. On my Xtool bidirectional computer it shows a part number that has to do with the battery the black box that the groind wire goes to is not there and person before changed the battery. But that cannot possibly cause the issue.

YesItsAGTR

I have the Xtool scanner works with mercedes. Ltft do you mean Left bank 1+2 02 sensor reading? If so what should I look for?

CaliBenzDriver

you're looking for misfiring and lean trims indicating poor combustion.

e350forme

these too?

BlackML550

As previously indicated check your fuel trim readings as well as misfire count. It also possible that you have a vacuum leak somewhere. That could be as simple as the airbox not being refitted properly. When the engine is cold, spray some brake cleaner around anywhere like airbox seal, inlet manifold seals etc. A rise in rpm will signal a leak. But only when cold or you'll start a fire. Have an extinguisher ready. Before you go spending I'd look at the fuel trims and if they're greater than +/- 8% thats telling you its something telling the ECU to over/under compensate. Also do some other maintenance like a MAF sensor clean. At least then your starting from a sound base.