How to Burp Your Car's Cooling Systemby Robert Moore
Clearing air from your car's coolant system is a fairly easy task. You need a floor jack, a set of jack stands, a helper and some extra premixed 50-50 coolant that is compatible with your vehicle. Make sure the engine is completely cool before attempting to open the cooling system.
Starting the Process
Lift the front of the vehicle and support it on jack stands placed below the subframe rails. Loosen the radiator or coolant pressure cap and wait for the pressure to escape the system. Remove the cap. Look for a coolant bleeder valve on the thermostat housing or the upper radiator hose assembly. Some cars have them and some do not. Turn the bleeder counterclockwise, if equipped. Add coolant to the radiator until coolant begins to flow from the bleeder valve. Close the bleeder valve.
Removing the Air
Set the heater controls to the maximum heat setting, then start the engine. Let the engine idle until it reaches operating temperature and the thermostat opens. Have a helper increase the engine speed and hold it at 2,500 rpm for 30 seconds. Watch the coolant level and continue to top it off as needed. If the engine begins to overheat, shut it down, wait for it to cool and start this section again. You have cleared the air out of the system when the coolant level holds steady and the heater blows hot air. Install the radiator cap and shut off the engine. Lower the vehicle to the ground.