Re: Coolant mystery
Is the radiator completely topped of with coolant? Depending on the outside temperatures, the cooling efficiency of the radiator is better (with low outside temps) or worse (with high outside temps). During winter operation for example with low outside temperatures, the radiator can more easily disipate the heat and the thermostat will also open less.
Also when you start a cold engine, the coolant will circulate through the engine only until the right coolant temperature is reached and the thermostat will start opening, allowing the coolant to circulate through the radiator. Until that point the engine coolant temperature can be normal, but the coolant in the radiator still cold.