My wife just bought a "Starmarked" 1993 190e 2.6 w/76,100 miles from a local MB dealer. Very clean, well-maintained one owner car. Strong engine. The only problems we've seen are a mildly rough idle (like one cylinder missing occasionally) and some oil consumption (about 1.5 quarts in 1100 miles). No obvious smoke at acceleration.
It probably needs valve seals and guides, I would guess?
The real question is how likely will the dealer cover this repair under their much ballyhooed "Starmark" warranty?
I'm not too crazy about a $1000 repair bill for a car we've owned less than a month.