Heres a link to ETKA (through Google Translate) if you select Audi 100/avant (top left) then 1984 model you can then select the engine and clutch bit, you can then see S751:KU down the right side, I think that must be the engine that you have.
I had a quick look and the only temp senor that I can see is one in line on one of the heater hose's (under water cooling),can't see an oil temp senor at all.
Here you have a look.
http://translate.google.com.ar/trans...at%2Fau%2Fa100
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