Sounds like a vacuum issue with the modulator.

Doubt that trans needs overhaul!

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Thank you, thats what I also thought.

Because of lacking service manuals/Mercedes service here, how can a vacuum be tested? The shops here don't even have a gauge (!).
If possible, I would check it myself, but where to start?

Could the EGR or MAF cause this behavior too? Or even the Vaccum modulator valve (I think thats what you meant with vaccum issue with the modulator)?