It's quite possible this problem isn't transmission related, but that is my best guess at the moment. I'm wide open to any other suggestions.

I'm not normally a diesel guy but bought this as my daily thrash because of it's history, condition & because it has an interesting engine, a DOHC 5 cylinder, 4 valve, intercooled turbo which has surprisingly sprightly performance & pretty good economy. It also runs quite happily on veg oil. Unfortunately, I think the 722.612 5 speed auto transmission is starting to act up.

Occasionally it feels like it's trying to pull away from a stop in much too high a gear. It makes no difference if I manually shift to 1st or 2nd or any other gear, it still pulls away very sluggishly. If I move the shifter up to P & then back into D it will select the correct, lower gear & pull away as it should.

Also, occasionally after brisk acceleration it will hang onto a lower gear far too long & be reluctant to change up after I've eased off the accelerator or even taken my foot off it completely & coasted.

Had it on a Star & there are no g/b or engine faults showing, ATF level was good. ATF was changed in July '07, 42K miles ago, when a new transmission control unit (026 545 91 32) was also installed, all at an MB dealer. The car has 124K on the clock now.

This is a car with full history & every receipt from day one (including factory collection paperwork) that I bought from the original owner, a wealthy, retired 70-ish year old who looked after it properly & never abused it. TBH I'm no longer sure whether it's a gearbox issue or an engine one. Might even be something neither I nor the MB independent who Star'ed it have thought of.

Anybody got any idea what the problem could be? I'd welcome any suggestions or help.

TIA.