I have a 1983 BMW and the temp sesnor for the Motronic by Bosch is still original.
The problem is most likely in the CONNECTOR. Very often the connection goes bad (road salt in winter, corrosion),....so disconnect the Connector to temp sensor and give it a good clean, spray some WD-40 to both the sensor itself and the connector and reconnect.
This should solve the problem.
I change my Thermostat every 60K so if yours is due then do it but do not expect changing the Tsat to solve this problem.
let us know how it works out.
cn
1998 V70
1983 BMW 735i
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