D5 Judder at 2kRPM 6th Gear
 

Hi guys,

My (new to me) C30 gets a judder on the motorway at 2k rpm in 6th. It's only there from 2000 - 2200 rpm and only in 6th, the power is still there and smooths out after that and is fine before. It feels like torque steer but you can feel it through most of the car.

Does anyone have any ideas?

Do you get the same thing at 70-75mph in any other gears? i.e. could it be wheel-related rather than engine/transmission? Just thinking, that sort of speed is prime territory for tracking/tyre balance issues.

You notice it most in 6th, 5th does it ever so slightly but not as noticeable. Maybe I'll get the tracking checked.

That does sound like a front wheel balance issue to me, if it's making the steering wheel wobble in your hands. If you feel it through the body of the car then it may be rear wheel balance.

This sounds like it is EGR valve related.

:star-wars-smiley-01

Thanks for all the replies, turns out the front two alloys are buckled and the back two were out of balance by 15 grams and 65 grams. Time for a refurb I think.