Pinpoint Test

WARNING: Always allow the engine to cool before opening the cooling system. Do not unscrew the coolant pressure relief cap when the engine is operating or the cooling system is 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 serious personal injury.

CARRY OUT INSPECTION AND VERIFICATION
1. Carry out Inspection and Verification. REFER to Symptom Chart(s) .
  Were any concerns found?
  1. Yes: REPAIR as needed. TEST the system for normal operation.
  2. No: GO to 2 .
CHECK FOR AN AIRFLOW OBSTRUCTION
1. Check the radiator or A/C condenser for an external obstruction such as leaves or cardboard.
  Is an obstruction present?
  1. Yes: REMOVE the obstruction. TEST the system for normal operation.
  2. No: GO to 3 .
CHECK THE ENGINE COOLANT LEVEL
NOTE: Allow the engine to cool before checking the coolant level.
1. Ignition OFF.
2. Visually check the engine coolant level in the coolant expansion tank.
  Is the engine coolant level within specification?
  1. Yes: GO to 4 .
  2. No: ADJUST the engine coolant level as necessary. GO to 4 .
PRESSURE TEST THE ENGINE COOLING SYSTEM
1. Pressure test the engine cooling system. REFER to Cooling System Pressure Test .
  Does the engine cooling system leak externally?
  1. Yes: REPAIR or INSTALL new components. TEST the system for normal operation.
  2. No: GO to 5 .
CHECK THE ENGINE COOLANT FOR AN INTERNAL LEAK
1. Inspect the engine coolant in the coolant expansion tank for signs of engine oil.
  Is engine oil evident in the coolant?
  1. Yes: REFER to SYMPTOM CHART: ENGINE PERFORMANCE .
  2. No: GO to 6 .
CHECK THE ENGINE OIL FOR COOLANT
1. Remove the oil level indicator from the engine.
  Is coolant evident in the oil?
  1. Yes: REFER to SYMPTOM CHART: ENGINE PERFORMANCE .
  2. No: GO to 7 .
CHECK THE COOLING SYSTEM FOR COMBUSTION GASES
1. Using 105R0110 (-), following the instructions supplied with the tester, check the coolant for combustion gases.
  Are combustion gases present?
  1. Yes: REFER to SYMPTOM CHART: ENGINE PERFORMANCE .
  2. No: GO to 8 .
CHECK COOLANT CONDITION
1. Check the coolant for dirt, rust or contamination and check the coolant concentration using ROB75240.
  Is the coolant condition OK?
  1. Yes: GO to 9 .
  2. No: FLUSH the engine cooling system. REFER to Cooling System Flushing . TEST the system for normal operation.
CHECK THE ELECTRIC COOLING FAN OPERATION
1. Start the engine.
2. Place the climate control function selector in the MAX A/C position and the blower motor switch in the HI position.
  Did the electric cooling fan operate?
  1. Yes: GO to 10 .
  2. No: DIAGNOSE the electric cooling fan operation. REFER to the SECTION 3: SYMPTOM CHARTS .
CHECK THE COOLANT PUMP OPERATION
1. Start the engine.
2. Allow the engine to run for 30 minutes. Place the climate control function selector in the MAX HEAT position. Feel the heater outlet hose.
  Is the heater outlet hose hot?
  1. Yes: GO to 11 .
  2. No: INSTALL a new coolant pump. TEST the system for normal operation.
CHECK THE THERMOSTAT OPERATION
1. Start the engine.
2. Allow the engine to run for 30 minutes. Feel the lower radiator hose.
  Is the lower radiator hose hot?
  1. Yes: CHECK the temperature gauge operation. REFER to DIAGNOSTIC ROUTINE D : Incorrect Temperature Gauge Indication.
  2. No: GO to 12 .
VISUALLY INSPECT THE THERMOSTAT
1. Carry out the thermostat visual inspection. REFER to Thermostat .
  Is the thermostat damaged?
  1. Yes: INSTALL a new thermostat. TEST the system for normal operation.
  2. No: INSTALL a new thermostat. TEST the system for normal operation. If the engine still overheats, INSTALL a new radiator. TEST the system for normal operation.