I"m reviving an old thread by saying that I have a 95 S320V with the same problem. My first order of business was to check the spark plug gaps, and see how she runs tomorrow. If still missing, I'd probably do new plugs and wires.
Interesting thing is, that when I restarted the car (just shut off and restarted) it was almost gone......
I might start a new thread on this problem.....

__________________
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Too many people tip toe through life, never attempting or doing anything great, hoping to make it safely to death... Bob Proctor

'95 S320 LWB
'87 300SDL
'04 E500 wagon 4matic