I just took my 300E in for a big service (big $$$'s). For kicks, I asked them to diagnose my rough idle. It was a 'gentle' rough idle that only gave the car a little nudge every few seconds when idling at a stop light... not a huge deal.
Well after being scoped and fondled, the idle is a constant rocking/heavy idle. It's worse than it was.
The diagnosis: maybe swap out the injectors, fuel distributor, maybe even motor mount. Great ideas. The same shop performed ALL this work for a previous owner 10k miles ago. Now they think a compression ring in #2 is failing and they hope it works itself out. Works itself out???
Ok, they can't find the problem. But make it worse???
My plan is to drop the car off on Jan 2, take a loaner, and let them think about it for awhile.
I would appreciate other thoughts.