The engine is a Chevy 1990 3.1 L with 200,000 + miles on it. I wanted to check the flow of coolant in my radiator, and top it off once the thermostat opened. .I removed the radiator cap from the cold engine, and stated it up, waiting for the thermostat to open.
When the engine was up to temperature, the coolant spurted/splashed out of the radiator filler neck, I've got a feeling this can't be good. Can anyone with some experience in these matters give me some clues?
I can top off the radiator, and after about 60 to 90 minutes of driving, the coolant level is down 1 - 2". Yet there are no external leaks that I can see. Nor has a shop that has pressure tested the system found any problems
Any thoughts on this would be appreciated.