Whilst I have had some very helpful replies, of which I have been appreciative, no one has experienced or been able to offer a definite answer to the problem I have regarding the clutch in my 190E. Pressumably the relatively small number of manual transmission Mercedes means that there is less likelyhood of someone else having encountered this problem. That's why I thought my best chances would be with one of the MB techs here.

To save me explaining the problem again, you can see how the story unfolds from my previous threads. They are (most recent first):

Clutch master cylinder question W201 & 124.

"High" clutch pedal problem. Any ideas?

190E clutch replacement. Any tips?

Whilst throwing a new clutch at it may temporarily mask the problem, I don't believe it is fixing the real cause. Rather than blindly replacing parts I would prefer to have either diagnosed the cause myself or have a well informed diagnosis from someone with previous experience with the problem. I would be very appreciative if any of the techs here can advise of experiencing the same problem. My concern is that if I give up, and get a workshop to fix it, they may end up blindly throwing parts at it which I am quite capable of doing!

Thanks,
Greg

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107.023: 350SLC, 3-speed auto, icon gold, parchment MBtex (sold 2012 after 29 years ownership).
107.026: 500SLC, 4-speed auto, thistle green, green velour.
124.090: 300TE, 4-speed auto, arctic white, cream-beige MBtex.
201.028: 190E 2.3 Sportline, 5-speed manual, arctic white, blue leather.
201.028: 190E 2.3, 4-speed auto, blue-black, grey MBtex.
201.034: 190E 2.3-16, 5-speed manual, blue-black, black leather.