I have a 1990 Honda Accord. The coolant temperature, if normal, is right at the middle of the gauge. Recently, it has been as high as
4/5 of the gauge. I took it to a mechanics, thinking I might need a new water pump. He checked it, told me the water pump was not leaking, and did not change the water pump.The thermocouple is fairly new, less than two years.
What might be wrong?