Hi, I've turned to the wisdom of the Ford forums for help, would really appreciate any feedback if anyone has had a similar problem.

I had a brand new turbo and full service carried out on my ford mondeo 2.0 TDci estate (130) year 2004, mileage 80K.

Since getting the car back from the garage the car ticks over beautifully, cruises at 60 / 70mph smoothly but at 50mph the car judders, I've had the garage recheck the work, checking for splits and loose hoses, they have rechecked the turbo and even had the machine up on diagnostic but can find absolutely no fault, all the codes come back as fine, I had the engineer who carried out the work take the car out and specifically asked him to get to 50mph to see if the same judder happened to him, he also experienced the judder but cannot explain the problem.

It only happens in the 45-50mph speed and the only way I can explain it is as if the engine is spluttering, like its cutting out very quickly on and off but with a noticeable "judder" to the ride. Since getting the car back there is a considerable amount of exhaust smoke (which isn't blue or white) when changing from 3rd,4th and occasionaly in 5th,and more smoke than I've had before.

The full service on the car was carried out by a reputable garage and Ford parts were used, I intend to take it back to the garage but does anyone have any clue to what this could be I am totally stuck?

it could be a gummed up or sticking egr valve, this can be removed and cleaned, also check the intercooler pipe for splits,its the large pipe from the bottom of the egr valve.