Reply To: Cooling System '54 Mercury
Virgil & Sue Klein
It seems to me that everything is working fine if the temp is in that range. The “dot” between middle and hot was originally supposed to show a temp of 180 degress. With years of use it might not be that accurate but certainly does not reflect any overheating problem. If you have a 180 degree thermostat that is exactly were the temperature should be. If you want it below that switching to a 160 degree thermostat will not cause any problems. One way to check the accuracy would be to get the car warmed up with the temperature gauge at your “normal” reading and then check the coolant temp with a thermometer or you could install an aftermarket temperature gauge. From what you describe I do not think you have an overheating problem at all.