Please put some punctuation in that huge sentence, otherwise it can be read at least three different way. The logic is confusing too. It is not overheating but there is no coolant in the engine? It was not just that the reservoir was low or empty, was it? Flushing the engine isn't going to accomplish anything. Although thermostats do not fail very often, once you replaced it, you have to bleed the air out from under it when you refill the coolant. If you did not do that you can get lucky sometimes and it will bleed by itself. A lot of thermostats have small bleed holes in them for that purpose. If that air pocket burped out on its own, coolant level in the reservoir, and possibly the radiator would go down and all that would be needed is to refill them.
Once the system is bled and full, if the overheating occurs again, it is likely due to a leaking head gasket. Combustion gases pool under the thermostat causing it to not open. Thermostats open in response to hot liquid, not hot air. There is a chemical test you can do to check for a leaking head gasket. Air is drawn from the radiator through a glass cylinder with two chambers partially-filled with a special dark blue liquid. If combustion gases are present, that liquid will turn bright yellow.
Friday, August 3rd, 2018 AT 7:20 PM