Dutch
I had (am having) a similar problem with my GL320 CDI. Took it in 3 weeks ago to have a "sticking" upshift checked out. Turned out that with the instrumentation on the car the tech was able to confirm that the 4-5 upshift was occasionally not happening when it should (or when it was commanded to by me). Dealer ordered a new 'valve body' in, installed it and did a ECU reflash that the magic computer from M-B said was necessary (I was never able to find out what the reflash was supposed to do/take care of). Long story short - when I got the car back in two days - a 2 hour drive for me each direction - the SA told me 'bad news, the new valve body wouldn't adapt. They've tried every trick they know of." "Have to do it again." we are still waiting for the parts to arrive! No word for a week now!