Hi all,

There has been many threads with various 'try this' options so I thought it best to create a new as I'm in desperate need of guidance.

My 2013 2litre Manual Diesel Smax has developed a severe judder/stutter/hesitation on touch the accelerator, have had many opportunities to test.

Car has had a Service, new tyres, brakes, fuel filter, EGR checked and injectors initially looked & MOT but still it appears. The garage initially could not replicate the problem but is worse on long motorway cruising. He did experience a small judder eventually. 

Symptoms

Usually happens after 45 mins from cold, then judders when touching the accelerator between 40-70 mph, when you take your foot off the pedal the judder goes, as soon as you touch it it reappears. Making the journey from Sussex to Scotland an absolute nightmare. There is no loss of power, just the judder, on occasions you ca find a sweet spot for a few precious moments of normality, then as soon as you touch the pedal it reappears. 

Apart from the severe judder the car performs with no issues, there are no warning light indications and no loss of power. There are no issues with gear changes. As I say the car can perform for about 45 mins first thing without issue then it just appears. e.g. drove to Guildford yesterday a journey of 40 mins with no issue, then after a 2 hour stop, travelled 220 miles same day for 4 hours with constant juddering. Had to constantly change gear to increase revs as when at 2000rpm it seems worse. Nightmare.

With all the threads, it seems there is a common problem but no clear solution or cause from what I have read.,

Anyone help as garage at a loss. Need a wizard who knows about this please.

I may/may not have read/noticed previous threads but to start this new effort I would ask/suggest:
Monitoring various, all, relevant parameters using Forscan with the help of an assistant (need to keep driver's focus on the road - legal and safety reasons) OR recording those parameters for analysis later.
Changes when the juddering is taking place are the presenting symptoms.

I'll wait to see how this thread develops (or even if my suggestion is a valid, accepted route)
Then "we" would need to have a set of PIDs to view/record with suggestions of how these contribute to the problem and only if absolutely certain, suggest repairs, or parts that may be required?

Your  starter for 1!