I am working on a family member's 2001 SLK230 and noticed that no matter what temperature the car is running, the overheat light on the analog temp gauge is illuminated. The car does not run over 80C when at operating temperature. All the fluids are topped. I am aware of the coolant level sensor issue, but that sensor has been checked and is functioning. Is this fault with the gauge related to the coolant temp sensor directly connected ot it? Also, where is the gauge coolant temp sensor located on the engine of an '01 M111 motor?

I don't know if this will help, but I have a Chevy truck with a coolant temp. gauge and a high coolant temperature light. The gauge has a sender somewhere on the engine, and then there is a separate temperature switch for the light.

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1984 300D
Euro spec, 5 speed
217,000 miles

Is the coolant low?

-J

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1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

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