Hi,
I recently had an issue on my Passat where at about 3500-4000 rpm it would start coughing and spluttering and wouldn't rev any higher as if it was being choked. It seemed to be worse in the colder weather. Anyway i wasn't too worried about it as it did cause that much of an issue however i have just been on a trip around europe and the problem has gradually gotten worse to where the car is practically undrivable now. It literally will not go above 2000rpm without violently coughing and juddering. We have been pottering around at 60mph on cruise control the whole trip so it's not been subjected to any high rpm. I started it up this morning on the drive way and if you put your foot to the floor it revs to about 3000 rpm back to to around 2000rpm and bounces around between the 2. The engine wasn't up to full temperature and it did pump out excessive amounts of diesel fumes.
Can anyone point me in the right direction. Could it be EGR related?
Regards
Matt