Blue Goose

Makes sense. Will do before taking things apart.

Status and question I have flushed the radiator with a diluted Simple Green and distilled water solution. I ran the engine for about 5 min. The block was getting hot and the large hose was remained cold. I have since rinsed the radiator core with more distilled water and will drain again. Waste water was pretty clean. No large about of dirt or metal (none). Question How can you tell if the over heating is thermostat or water pump? This is a relatively new water pump with very few miles on it. Replace when engine was rebuilt 6 years ago.

Thank for the info guys.

My 1947 P15 Special DeLux just started to overheat. It stays in a heated garage most of the time. I only drive it 150 miles per yr. I had the engine rebuild about 6 yrs ago. Still using the original radiator with new water pump and thermostat. Not sure of the cause yet. I am going to try a radiator flush with Simple Green detergent and water (youtube). Not sure it this is safe on a copper / brass radiator. Any precautions out there. Tx BlueGoose47