My BMW RPM unstable up down

[KelvinTeoh]

Since i change my engine oil seal after removing the plug coil and re-plug in again,my car starting loosing power,recently the engine start vibrating!any advise from u?Actually i face the same problem last year after i change new plug.After i replace newcoil it ok already,Is it the OEM coil so fast damage?

 

[J39]

Many reasons caused engine vibrating.
Did the problem disappear for a while if you off your engine ?? or it stay ??