How do I know if my coolant is not circulating?
After your engine is warm, feel the radiator near the bottom. If it's still cool but the top part of it is hot, you're not circulating coolant. That could also mean a stuck thermostat though.
How can I tell if coolant is flowing?
You can do this by removing the radiator cap on your car to check the coolant flow. Start your car's engine and allow it to idle. Look through the radiator filler neck to see if the coolant flows.
Can you see coolant circulating?
Take your radiator cap off and note the coolant level. idle the vehicle until it's hot enough for the fans to kick on, maybe 10-15mins depending. When they do, you can look down in your radiator and see the coolant level drop and probably see it circulating as well.
How long does it take for coolant to start circulating?
In general, it takes only a few seconds for the coolant to circulate through the engine block and reach the thermostat, which regulates the temperature of the coolant. Once the thermostat opens, the coolant will begin to flow into the radiator, where it will be cooled by air passing over the radiator fins.