Strange vibration when coming to stop and rattle when pressing accelerator.

Hi guys.
My 2012 2.0Tdi with 100k miles has just started a strange rattle when pressing the accelerator pedal when stationary and when moving changing gear. When stationary in neutral the engine will shake and can be felt in the car for a moment when pressing the accelerator. Also I have this vibration in the car when coming to a slow stop at times. I thought the vibration could be due to warped discs so I purchased new rotors and pads and plan to have them fitted next week. But I'm not sure now that this is the issue. Any advice is greatly appreciated before I pop it into the garage. Car has full service history. Tbelt done 10k ago.