[BM2020]

Hello

I have a 318i E46 1999 model that has recently had a major service such as oil change, oil filter, spark plugs, fuel filter and air filter, however it still seems to be rough and shaky while on idle.
I am thinking it could be the spark plug leads, as they haven't been replaced. Has anyone experienced the same issue and how did you resolve it please? thank you

 

[marcozandrini]

The first step in diagnosing a problem is to scan the engine computer (DME) for codes. It’s likely that the engine has vacuum leakS. The typical codes that indicate vacuum leakS are P0171 and P0174. The intake will have to be smoke tested to find all of the vacuum leakS.

 

[lgr122]

Vacuum leak, or spark plugs/-leads not assembled properly.
That's where I would begin to search, but scanning codes would help to catch problem quicker as Marco suggests.