Annoying & mystery vibration & noise

My S350 has done 59,000 mile. From cold it drives like new, however recently after about 40 miles of driving the car starts to vibrate and a noise best described as a pump working very hard can be heard and then around town the engine appears to be running rough. I have had the wheel bearings, engine pulleys, turbo, exhaust, brakes, tyres, wheels examined but we cannot determine the cause. I always look after my car and is serviced on time. Has anyone else come across this problem and if so what is the solution to this mystery. Thanks  

Vehicle
Year
2010

MercedesMedic
Mar 9, 2018 @ 07:30 am

Moh Rashid
Mar 11, 2018 @ 06:07 am