W176 A250 Manual - Jerking / Bunny Hopping Under Acceleration

[JDB96]

Hi all, having a spot of bother with the wife’s A250. It’s very intermittent but sometimes when accelerating (at any rate in any gear although she says it’s more common in 3rd), it does this thing that I can only describe as a violent jerking. It’s as if someone is pumping hard on the brakes while accelerating. It almost feels too violent to just be the engine losing power e.g. with a fuel or spark issue, but I could be wrong.

I will get it booked into our nearest specialist, but in the meantime is this something anyone has experienced before? I’ve seen a few threads on it across various Mercedes models but none with a successful resolution.

Thanks.

 

[Capristeve]

Did you ever get this sorted? I'm having the same problem with my 2007 vito, if I pull out of a junction and accelerate hard, it jerks violently, exactly how your describing yours, especially in 1st and 2nd,

 

[JDB96]

Did you ever get this sorted? I'm having the same problem with my 2007 vito, if I pull out of a junction and accelerate hard, it jerks violently, exactly how your describing yours, especially in 1st and 2nd,

Yep, crank position sensor. About £30 and a couple hours work on the A Class. Best of luck!

 

[Capristeve]

Yep, crank position sensor. About £30 and a couple hours work on the A Class. Best of luck!

Cheers for the reply, I'll take a look at that, its actually just gone into limp mode this evening,

 

[Capristeve]

Changed the crank position sensor last night, still the same unfortunately, my mate plugged his computer into the car and took it for a drive, he said the only thing that came up were the readings for the egr were all over the place, and everything else seemed fine, so ill try that next,