W211 (E320) )M642 - lack of power

[David404]

Driving back from Devon today car lost power, not misfiring, no horrid noises but severe lack of power, wont run past 3000RPM and NO EML or any other warning lights on.

when up to speed it runs along just fine you wouldn't know there was anything wring its only on opening the throttle that there's any evidence of a fault.

Off to the workshop on Monday but anybody with any ideas, any common issues?

 

[4life211]

First thing to do is : reading the codes stored in board.Then to see to do .

 

[SL300-24]

Does it clear once you turn it off and restart?

 

[David404]

Does it clear once you turn it off and restart?

Seems OK for a short time but by tie engine is warm fault is back.

The EML is NOT and has NOT been on.

 

[4life211]

No eml?? Sounds like transmission problems.

 

[David404]

No eml?? Sounds like transmission problems.

That was my first thought as first time I noticed it was when I accelerated (or tried to) away from some slow traffic it didn't downshift. but even allowing for the lack of downshift it should have pulled away faster. With foot on the floor the revs were rising very very slowly. In manual mode it changes up and down fine but wont rev to over 3000.

 

[Azeem]

https://www.mbclub.co.uk/forums/engine/144927-lack-power-cdi-what-do.html

 

[David404]

Will see tomorrow, will pop into my regular Indie and see if they can fit me in. The link Azeem posted is pretty much were I am so looks like something on the air intake side of things. Hoping its not too much £££.

Helpfully the EML had today decided to illuminate.