Slow boost with sluggish speed up and high gear change time

[Hamza Aanan]

Hi everyone,

I have a C250 which recently serviced however garage said transmission and brake fluid air filter they are good in condition and doesn't need to be changed. So following MOT prep he done some work in exaust and front right shock absorber. 1 week later stranded on road cz starter blown off. Then replaced by same garage. 2 weeks later inter cooler hose(R) blown away. Took back to him and after diagnosis said it got transmission issue n need to service by transmission expert. Then to it to mercedes specialist with MB star diagnosis found out inter cooler blown off and need to replace it. After replacing it still no boost as before. Same sluggish speed up or with high rev sometimes hard to upshift more over 2 and or 3rd gear. But if it gently slower than regular rev than it goes up to 4th or 5th gear runs at max speed 40 to 55mph. When break pedal pressed sometimes it gives jarky feeling. Took back to MB star garage they said need time and long waiting to find out problem. Any chance anybody could recommend what's wrong!!!

Thanks
Hamza Aanan