Vibration

[keenie]

Hi All
Please can someone help me, i own a 1996 Polo 1.9 SDi, and it has over the last couple of days started acting strange, when i hit a pothole etc the car starts to vibrate, but the strange thing is, i can come to a complete stop and dip clutch and the vibration is still there, but the idle is unaffected, then if i move off i either hit another bump or i hear a ping and the car returns to normal, has anybody got any idea's for this strange problem.

Thanks in advance.