W124 220TE idle

[3ps]

Hello all,

My W124 idles at about 800 in park and neutral.

When I put it into drive and keep my foot on the brake it drops to about 500-600. This feels slightly low with a mild vibration.

If I have the aircon on it can drop lower as it kicks in. So low that the car kindof cuts out, restarts and lurches forward.

How do I adjust the idle setting?

Thanks.

 

[alexander patie]

you don't! it is all automatic, but it may be worth cleaning any carbon from the throttle valve.

 

[3ps]

OK as I guessed.

How frequently would the throttle valve need cleaning? It was done about 18months before I took posession of the car.

Are there any other factors that might cause the car to nearly cut out like this?

 

[kth286]

my similar design engine has never had throttle cleaned in 169,000 miles.

check the regeneration valve on the NS inner wing is pulsing after engine is at normal temperature.

It has MOT on top of it and you can feel and normally hear them pulse at about 2 beats per second.

They can stick in open position, and allow petrol fumes from tank to be sucked into engine at inappropriate times thus stalling engine etc.

 

[3ps]

Thanks for that. I don't think it is.

 

[kth286]

if that is working OK, then get your local friendly Merc specialist to read the fault codes and see what that shows.