Help diagnosing an overheating issue on a 1950 Dodge

Question:

The 1950 Dodge that I use as my everyday driver recently developed an engine temperature problem. After starting the engine the temperature gauge indicates well past the normal mark, but then it returns to normal. There is a smell of coolant in the car, but no sign of leakage under the hood. After the gauge returns to the normal position, it stays there and the engine runs fine. I replaced the 160-degree thermostat with a new one, but the problem remains. Can you suggest any causes or remedies?

Answer:

From the description of the problem, a logical deduction is that something is delaying the flow of engine coolant to the thermostat, thus preventing it from opening until the coolant in the block has reached an abnormally high temperature. There may be a restriction in the engine’s cooling passages or in the radiator. It is probably worthwhile to back flush the entire cooling system to clean out accumulated rust, scale and sediment. It is also possible the water pump is not performing as it should because of a slipping impeller or other malfunction. Check the heater core for any signs of leakage. It may be seeping enough fluid to cause the smell of coolant you describe while not leaking enough to leave a puddle.