Please help, I've been through the web trying to find out any info on the possible fault of my C200 cdi Automatic 2004 with 130k miles.. I have had this car for the past four years and 99% has been trouble free driving. Last week I took the car to my local specialist for a service and the replacement of two suspension arms at the front. The engine management light had also been on for a prolonged period of time pre service and on three occasions the car developed a fault where it would not rev above 3000rpm. So I thought I'd get the car all that it needs so as to have a another year of trouble free motoring.
Whenever I got the car back the light was still on and the mechanic told me to take it for about a 20 mile burn up the motorway to clear out the Cat, this I done but it did not clear the fault. the car was running very well though...but within a week the gearbox broke and what I mean is, it drives through the gears changing quicker than usual and whenever it reaches 40mph it jumps out of gear and will not go into gear again again until about 20-30 mph....So I took it back to the garage and after they looked at it they came back saying some sort of valve body could be at fault because they tried all the other usual suspect parts...? now, I'm not a mechanic but do know a little because the next thing he said was that he would look at the car again on another day and try swapping the rear wheels with those from another car as my rear wheels were a different size to the ones on the front. This has left me doubting the mechanics ability because I now know that this is not uncommon.. but I need to spend £1000 to make the car run good again...this comes on top of two new rear tyres with front wheel alignment a service, new pads all round and some kind of suspension rods totaling £650 (I'm just detailing these things incase they have a relevance) so far... I'm at a loss and need help to repair my car that is sitting idle in my driveway...please help..

Do you have a service record for the 130,000 miles the transmission has done ? .The oil is meant to be changed every 38,000 odd miles.

Sounds as if you have two different issues. .

I would try for a second opinion at a dedicated transmission specialist.

Do you know the code number the car was throwing ?

Good luck & let us know of the outcome.

first step.. fault codes need to be read in Engine, gearbox and ESP
and post them here.
You cannot use odd size wheels on MB cars. All 4 wheel speeds are processed by the ESP and transmitted on CAN bus if the Gearbox recieves odd wheel speeds you are going to have issues, but this will be picked up in the fault memory.

+1 - Give us the codes. Wheel rolling circumference needs to be kept within about 2% back to front.

If I was to take a WAG at the problem it sounds like a failing conductor plate in the transmission triggering one of the limp modes. Predicated on the basics that fluid level is correct & filter & oilways clear of obstruction. This is a guess & could be way wrong. Syptoms are familiar though.