Power loss once engine warms up

[Exocet]

nice one Phil C, the pictures were useful too thanks. I will check once I have some daylight and see if this is the case for me.

I've noticed that the stuttering occurs when accelerating just over 2k revs, its ok if I accelerate smoothly but if done suddenly it stutters horribly at that point

 

[Exocet]

Quick update on my problem: yesterday my car went into 'limp' mode after stuttering itself silly, had to pull into a gas station and call the AA. I also contacted my mate who has a VW Golf and he had something similar and turned out it was the ignition coil. AA man came checked and sure enough it was one of the coils that failed. With the new one installed the car feels completely different now and almost like new. I'll probably change the other 3 now as these tend to fail.

If anyone gets a similar problem its an idea to check the coils out, it never occurred to me before but now I know better