Westwind

Hi,
I had raised this issue in winter, and responses I received were basically, I need to get the engine to warm up and so on. Now, its full blown summer, and I am still dealing with this issue, although at very random occurrences.

Well, for no apparent reason, while driving, the RPM will go up beyond 2000 even if I am on high gear. On low gears it will rise, and refuse to go down even if I have gathered enough speed. The noise level rises as if I am driving a stick and having a good time drag racing it. Seems like I get stuck in a certain gear, and the engine keeps rev'ing (thats the word, right?) and not letting the gears shift up. When I let the foot off accelerator the car starts slowing down very fast - and by slowing down I do not mean try to go to idle speed - this part is where it seems like its trying to apply brakes, although not in a sudden manner.

I know this is a problem because this behavior is random, and out of the norm that I am used to. So, I already know how it behaves normally. However, when it does, it drives me nuts as I feel it is going to do some damage.

Certainly, I am going to contact my service manager, but I am afraid when he takes it to test, it will not happen.

Anyone experienced this? Thanks.

HBerman

My 2011 E550 has been doing this during the months when the outside temp is above 85 degrees since it was new. The dealer loaded new software for the ECU which reduced the behavior, but did not eliminate it. Apparently there is an interaction between the A/C and the ECU. When the behavior happens it will immediately cease if I switch off the A/C for 5 secs. Weird huh? This reving / stuck in gear is not the same thing as what happens during the cold months when the program for the transmission keeps it in lower gears to warm up the cats. Someone posted many months ago that this issue happens primarily on the E550, and that a "fix" was being developed. My SA knows of no update yet.

Yosheego

I have the same issues. I have videos of it also...(you might not be able to tell much from the video, but i tried to my best to show what's happening, and you pretty much explained it perfectly)

https://mbworld.org/forums/e-class-w...-up-video.html

I guess it's a normal thing...it usually happens to me in the afternoons more, when the temp is hotter. yeh it drives me nuts, but i guess my last post on this thread, someone suggested that down shift it with the right paddle shift, which surprisingly, it does work, but i have to do it from time to time and yeh, it eats up some extra fuel too.

Westwind

OK, so 2 suggestions - either to turn AC off for a few seconds, or shift down. Will try and see if it works. Thanks!