W124 Engine "Cycling"

[Kiwibins]

Ola all

My 1995 W124 E320 cycles ie idles badly, generally whilst sitting at the lights (with or without brakes). Any reason/remedy? It does need a service but would this be enough to cause cysling at halt/slowly moving?

Greg

 

[jibcl500]

Try putting it Park whilst sitting at the lights or in traffic, try and save the life on the gearbox somewhat.

jib

 

[Blobcat]

Try putting it Park whilst sitting at the lights or in traffic, try and save the life on the gearbox somewhat.

jib

Moving between Drive and Park wears the gearbox more than leaving it in Drive. The guidelines from MB are unless you are going to be not moving for quite awhile (longer than a red light) then leave it in Drive.
Numerous threads on this and I use to switch from Drive to Neutral as I thought at the time it was better for the gearbox. I was wrong :-(

 

[Kiwibins]

So. It is a worn transfer plate between the box and engine? Or is it more...... What will it cost to fix?

 

[television]

What is the idle speed in D and N

 

[wireman]

All the proper books about driving say that you should engage the parking brake then select neutral at traffic lights this is good practice but it wont help diagnose your problem.
The question should be does it behave the same in neutral/park as it does in drive (with the hand brake on)?
In neutral there is next to no load on the engine, in drive there is an increase in load which may change the characteristics of the engine. The load is in the form of a locked gearbox input shaft connected to the engine by the torque convertor, the only thing doing any work is the torque convertor, tick over speed and transmission fluid level can affect this.
The general condition of the spark plugs etc and injection system will play a big part in how cleanly your engine runs.
If it needs a service get it done soon, it will not get better if you leave it.