In the last few days my A6 2.5 TDi car has developed a stutter/hesitate under acceleration and high speed cruising almost like having a large flat spot that lasts around 1/2 a second, every 2 or 3 seconds.
Most noticeably, this happens on the motorway under normal driving whereby at 1500 -2000 rpm the engine power dips then returns quickly, this was constant on my 1 hour drive home just now. There are no engine warning lights on the dash but it felt like a mis-fire.
The problem seems to happen throughout the rev range, there is quick dip in power and in the rpm then it will gather some power to accelerate then happen again and again. If I pull away from a round about slowly the problem isnt too bad but if I were to gun it, the engine would cough and splutter untill I backed off the power.
Last night driving home up the M11 she struggled past 50mph, first morning she is fine albeit when I stick my foot down for hard acceleration.
I have done some research but can't find much regarding this same issue, has anyone got any experience with this?
Any thoughts would be helpful