ESP/BAS lights come on at 5000rpm

[INKJET]

2000 model year CLK320 owned from new with 50k miles.

When accelerating in kickdown mode in either S or W setting on reaching 5000rpm the car stops accelerating and then the ESP in the centre info screen comes on with the BAS/ESP lights in lower left of instrument cluster.

Car drops in to safe mode and at idle it is very lumpy, switch of re start and all is well, at least up to 5000rpm.

Car going into MB dealer for a 50k service in a few weeks to include air and fuel filter + spark plug change.

Any help or ideas please?

 

[INKJET]

Just got the car back from Mercedes in Derby, MAF was the problem, it runs like new, to be fair probably better than new because the engine is run in now.

Would not hesitate to recommend Merc in Derby, the service was first class, done properly it is never going to be done cheap is it? but the point is my car feels like the day it came out the showroom nearly 8 years ago and thats what counts