M112 engine rough running/hesitation at certain revs

[E240estate]

Driving me mad this one. I have a 2003 E320 petrol. Runs and drives absolutely fine, very reliable.

When the car is standing still and the accelerator is pressed, there's a roughness at around 2k rpm and again at 3k rpm. Much more noticeable when cold, but always there.

I have changed loads of stuff, and cannot get any improvement. It's been like this for at least 2 years. Here's the lost of changed/eliminated parts

Spark plugs
Ignition leads
Ignition coils
Cam sensor
MAF sensor
Harmonic balancer/crankshaft pulley
Accelerator pedal
EGR valve
Crankcase breather hoses to air intake
Cannot detect vacuum leak spraying contact cleaner around
Oil and filters regularly changed
No fault codes or CEL

I have an icarsoft 2 but a bit clueless as to what to check with it, any help or ideas gratefully received thank you

 

[Oleks1992]

Driving me mad this one. I have a 2003 E320 petrol. Runs and drives absolutely fine, very reliable.

When the car is standing still and the accelerator is pressed, there's a roughness at around 2k rpm and again at 3k rpm. Much more noticeable when cold, but always there.

I have changed loads of stuff, and cannot get any improvement. It's been like this for at least 2 years. Here's the lost of changed/eliminated parts

Spark plugs
Ignition leads
Ignition coils
Cam sensor
MAF sensor
Harmonic balancer/crankshaft pulley
Accelerator pedal
EGR valve
Crankcase breather hoses to air intake
Cannot detect vacuum leak spraying contact cleaner around
Oil and filters regularly changed
No fault codes or CEL

I have an icarsoft 2 but a bit clueless as to what to check with it, any help or ideas gratefully received thank you

Smoke test your intake and check live data on DAS like for air mass, throttle body position etc...

 

[grober]

THESE CARS MAY HAVE AN ENGINE REV LIMITER WHICH MAY KICK AT LOWER REVS IF THE ENGINE IS COLD OR THE CAR STATIONARY! YOUR ONE MAY BE PARTICULARLY SENSITIVE???