Pinpoint Test B: The Engine Overheats
WARNING: This page is about a different car, the 2005 Mercury Mountaineer and 2005 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.
- B1 CHECK THE ENGINE COOLANT LEVEL WARNING: To avoid personal injury, do not unscrew the coolant pressure relief cap while the engine is operating or hot. The cooling system is under pressure; steam and hot liquid can come out forcefully when the cap is loosened slightly. Failure to follow these instructions may result in personal injury.
- Check the engine coolant level at the degas bottle.
- Is the engine coolant OK?
- Yes : GO to B2.
- No : FILL the degas bottle. GO to PINPOINT TEST A .
- B2 CHECK THE COOLANT CONDITION
- Check the coolant for dirt, rust or contamination.
- Is the coolant condition OK?
- Yes : GO to B3.
- No : FLUSH the engine cooling system. REFER to COOLING SYSTEM FLUSHING . TEST the system for normal operation.
- B3 CHECK FOR AN AIRFLOW OBSTRUCTION
- Inspect the A/C condenser core and radiator for obstructions such as leaves or dirt.
- Is there an obstruction?
- Yes : REMOVE the obstruction. CLEAN the A/C condenser core and radiator. TEST the system for normal operation.
- No : GO to B4.
- B4 CHECK THE THERMOSTAT OPERATION
- Key in START position.
Start the engine and allow the engine to run for 10 minutes.
- Feel the inlet and outlet heater water hoses and the underside of the upper radiator hose.
- Are the upper radiator hose and the heater water hoses cold?
- Yes : INSTALL a new thermostat. TEST the system for normal operation.
- No : GO to B5.
- Key in START position.
- B5 CHECK THE COOLING FAN OPERATION
- Key in OFF position.
Carry out the cooling fan component tests. Refer to the FAN CLUTCH TEST .
- Is the cooling fan operation OK?
- Yes : GO to ENGINE SYSTEM-GENERAL INFORMATION for diagnosis and testing of the engine.
- No : INSTALL new fan components as necessary. TEST the system for normal operation.
- Key in OFF position.