Slightly Lumpy idle when warm

[Wal]

Hi there, just finished getting my 99 z3 on the road and I’ve noticed the idle once the engine warms up is slightly lumpy,not misfiring or waivering up and down, it tends to sit at around 8-850rpm but feels occasionally like it misses a beat, is this normal for a 1.9 140 engine,seems more steady when the engine is cold for some reason? Checked for intake leaks and the breather pipe off the rocker cover seems fine too,it’s not cutting out or anything so guess it can’t be anything too much to worry about.Cheers

 

[colb]

You either have a M44 or M43 engine in your car, use a Vin decoder online to confirm which you have. If its a M44 engine these are known for a lumpy idle not a lot you can do to improve it other than ensure plugs are good and car is not setting any codes and has no air leaks.
The M43 engines idle is far smoother.

 

[Wal]

Cheers for the reply,I thought as much, it’s the m44 engine, I’m also finding bringing the engine down to a standstill at the lights it holds for a second or so at about 1000rpm and then drops to 850 when the car has completely stopped but guessing again this might be the norm