99 couger 2.5L 6 Cyl-temp gauge maxing out, overheating
I will normally remove rad cap when cool. Start engine, set heater in car to heat & turn on blower, if you use defrost setting, the rad fan &/or AC fan will come on, and you don't want that. Then while running with cap off, make sure coolant in rad is an inch or 2 from top of rad, and let it run. When engine gets to normal operating temperature on the gauge, you'll start to see more flow in radiator, and rad fan should come on shortly after, to cool the incoming hot liquid in the rad, that tells you the thermostat opened as it should, and the process starts again, engine coolant gets to temp, thermostat opens, hot goes to top of rad for cooling, and cooler liquid goes out the bottom to engine, etc etc. If your heater is not on while doing this, the coolant doesn't get to heater core in most cases, thus creates an airlock, or will cause level in rad to go down when it is turned on, and thus reduces amount of coolant in rad, plus airlocks in the entire system. So, let it run to the point that the rad fan comes on & off on it's own, about 3 times, while you watch the gauge, to make sure it doesn't overheat, if it does, shut it off and let it cool down & try again. if all appears good, top rad up if needed to an inch or so from top, put your cap on properly, add coolant to proper level in return bottle & try it and see what happens. Remember though, I am assuming thermostat was put in correctly, rad in good shape, fan is working properly as well as water pump doing it's job. If this method doesn't work, get back to me with results.
Feb 16, 2009 |
1999 Mercury Cougar