Component Inspection

COOLING SYSTEM (2ZZ-GE)

INSPECTION





1. THERMOSTAT

HINT: The valve opening temperature is inscribed on the thermostat.





a. Immerse the thermostat in water, then gradually heat the water.
b. Check the valve opening temperature of the thermostat.
Valve opening temperature: 80 to 84°C (176 to 183°F)
If the valve opening temperature is not as specified, replace the thermostat.





c. Check the valve lift.
Valve lift: 10 mm (0.394 inch) or more at 95°C (203°F)
If the valve lift is not as specified, replace the thermostat.
d. Check that the valve is fully closed when the thermostat is at low temperatures (below 77°C (171°F)).
If not fully closed, replace the thermostat.
2. RADIATOR CAP SUB-ASSEMBLY

NOTICE:
^ If the radiator cap is contaminated, rinse it with water.
^ Before using a radiator cap tester, wet the relief valve and pressure the valve with engine coolant or water.
^ When performing the following steps (a) and (b), keep the tester at an angle of 30° or more above the horizontal.





a. Using a radiator cap tester, slowly pump and check that air comes from the vacuum valve.
Pumping speed: 1 push every 3 seconds or more

NOTICE: Push the pump at a constant speed.

If air does not come from the vacuum valve, replace the radiator cap.
b. Pump the tester, then measure the relief valve opening pressure.
Pumping speed: 1 push within 1 second

NOTICE: The above pumping speed is for the first pumping only (in order to close the vacuum valve). After the first pumping, the pumping speed can be reduced.

HINT: Use the tester's maximum reading as the opening pressure.

Standard opening pressure: 74 to 103 kPa (0.75 to 1.05 kgf/cm2, 10.7 to 14.9 psi)
Minimum opening pressure: 59 kPa (0.6 kgf/cm2, 8.6 psi)
If the opening pressure is less than minimum, replace the radiator cap.