How to bleed coolant on 2000 Lincoln Navigator if it needs to be bleed.

The 200 character minimum is force you to give enough information and details so we can come up with an answer of value as quickly as possible. In this case, when asking an engine-related question, it sure would be helpful to know which engine you have. Regardless, I assume you didn't find a bleeder screw on the thermostat housing. If you already ran the engine and the heater is working and the engine isn't overheating, you're done. Any air will expel into the reservoir when the coolant warms up and expands.

If there's an air pocket under the thermostat, it won't open, the engine will overheat, and most of the time the heater will blow cold air. Thermostats do not open in response to hot air. They have to be hit with hot liquid. Look for a coolant temperature sensor or switch on or near the thermostat housing. Remove that while adding coolant to the reservoir or radiator. I prefer to do that with the ignition switch off until all sensors are plugged back in. That will avoid setting any diagnostic fault codes and turning on the Check Engine light. Reinstall what you removed when coolant starts to run out. At that point the thermostat will open, and any remaining air will work its way out.

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Then look for a sensor that can be removed to let the air out.

Gotta run. Library is closing in 2 minutes.

Happy to hear it's solved.