W124 220CE slow idle when coming to stop

[MBhowden]

Hi all,

I have been having a problem with idling, at any engine temp, when I come to a stop the revs drop to 600 to 700 and it stall on occasion.
If I put the car in neutral the revs lift and it avoids the stall.

I'm selling the car and a helpful prospective buyer located a connection on the air intake but said he thought one cylinder might be misfiring.

I thought to start with I would have the plugs changed and the throttle body cleaned, is that the best place to start?

Thanks in advance.

Rob

 

[MBhowden]

Can anybody assist please?

 

[E270 Owner]

MB Star session..............

Also

Don't want to scare you................. so stop reading..................... but the last engine I had doing this, stalling when slowing or idling, was due to worn valve guides.

Customer spent over £1500 in catalytic convertors EGR valve O2 sensors, he didn't get a Star diagnosis done and wasted a lot of beer tokens.



On a more helpful note:

Change the plugs clean the TBH
Also perhaps Change the:
Fuel filter
Oil & filter
Air filter


Good luck

 

[Auto-mobile]

Is it when you on the brake specifically? I have had this on a w124 once and there was a leak on on the vacuum from the brake booster.

I have also had similar on a e230 w210 same engine as yours, ended up doing a fine adjustment of the idle control arm which is next to the throttle cable.

 

[MBhowden]

Thank you for your help.

Does a Star diagnosis have to be carried out a t a Mercedes dealer?

 

[grober]

Clean the throttle body throat and butterfly plate edge with carefully with solvent. It usually the plate sticking. A misfire on one plug which is possible would be noticeable under acceleration as well as idle.

 

[kth286]

Thank you for your help.

Does a Star diagnosis have to be carried out a t a Mercedes dealer?

There are flash/blip codes available from the 16 pin diagnostic plug in
engine comparment.

It just needs a simple tool to read the fault codes; so really you just need
an Indie that is familiar with your generation Mercedes.

 

[kth286]

Perhaps someone on the forum knows of a suitable Indie in
your area.