Can anyone support me with a vacuum diagram for a 1998 E430 engine? I am chasing a serious engine shaking problem at idle and low rpm speed when cold. It becomes minor when warmed but still can feel it. It may be a vacuum leak. I already replaced the following items,
1) 16 new spark plugs
2) 8 new coil packs
3) 16 new plug wires
4) new MAF
5) all new O2 sensor
6) all new engine and transmission mounts
7) fuel injector cleaner
8) new battery
After all those parts replaced, no code at all, the engine shaking has improved by 50% but still there. I don't know what to do next, can someone give me some clue?

Could it be something with the harmonic balancer on the front of the engine. Check to see if it looks damaged or worn. It is not something that you want to get worse or have fail.

Thanks for your input. My car is fine when moving 10 km/h or above. Anyway I will check the HB later. But I really want to check if it has any vacuum leak. Anyone has the diagram?

engine shake, have check clogged injector?