C200 old shape running rough sometimes

[frady5]

Hi

Hope someone can shed some light for me? My C200 estate is occasionally running rough. When it does it feels like its on 3 cylinders (not sure if it is tho) but still runs and changes gear, just slowly and erratically.

To solve it, I pull over and switch engine off/on and it's gone. This happens prob every other day. I have also noticed that the auto box is doing odd things even when the engine is running well. Eg it will start off on 2nd and quickly change to 1st like its just realised its in the wrong gear.

Connected problem?

Thanks for you help!

 

[BlackC55]

It sounds like a possible air mass sensor fault. You need to get it plugged in to a Star firstly.

 

[frady5]

I am on a tight budget (I know, why am I driving a merc then). How much does a typical garage charge to plug in and diagnose?

cheers