Thermostat: Service and Repair
REMOVAL OF THERMOSTAT1. DRAIN COOLANT
2. REMOVE WATER INLET AND THERMOSTAT
(a) Remove the two nuts (4A-FE) or two bolts (4A-GE), the water inlet and thermostat from the water inlet housing.
(b) Remove the gasket from the thermostat.
INSPECTION OF THERMOSTAT
HINT: The thermostat is numbered according to the valve opening temperature.
(a) Immerse the thermostat in water and heat the water gradually.
(b) Check the valve opening temperature.
Valve opening temperature: 80 - 84°C (176 - 183°F)
If the valve opening temperature is not within specification, replace the thermostat.
(c) Check the valve lift.
Valve lift: 8 mm (0.31 in.) or more at 95°C (203°F)
If the valve lift is less than specification, replace the thermostat.
(d) Check that the valve spring is tight when the thermostat is fully closed.
If necessary, replace the thermostat.
INSTALLATION OF THERMOSTAT
1. PLACE THERMOSTAT IN WATER INLET HOUSING
(4A-FE) Install a new gasket to the thermostat and align the jiggle valve of the thermostat as shown in the water inlet housing.
HINT: The, jiggle valve may be set within 10°0 of either side of the prescribed position.
(4A-GE) Install a new gasket to the thermostat and align the jiggle valve of the thermostat so that it is positioned above the water inlet housing.
2. INSTALL WATER INLET
Install the water inlet with the two nuts (4A-FE) or two bolts (4A-GE).
Torque: 95 kg-cm (82 in.lb, 9.3 ft N.m)
3. REFILL WITH COOLANT
4. START ENGINE AND CHECK FOR LEAKS