Removing the thermostat
Removing the thermostat (3S-FE, 4S-FE).
1 - thermostat,
2 - gasket,
3 - inlet pipe,
4 - coolant temperature sensor connector,
5 - nut (M3 = 9.3 Nm).
Note:
- Do not remove the thermostat unless necessary.
- When the thermostat is removed, the engine tends to overcool, so the thermostat should not be removed even if the engine is overheating. The optimum operating temperature for the engine is around 95°C.
Removing the thermostat (ZS-T)
1. Drain the coolant (see section "Maintenance and general inspection and adjustment procedures").
2. Remove the inlet pipe and thermostat by unscrewing two nuts or two bolts, remove the gasket from the thermostat.
Thermostat check
Note: as a rule, the thermostat body is marked with numbers indicating the temperature at which the valve starts to open.
1. Immerse the thermostat in a container of water and gradually heat it up.
2. Make sure that the opening temperature of the thermostat valve is between 80-84°C. Otherwise, replace the thermostat.
3. Check the valve lift, which should be at least 8 mm (or more) at 95°C. Otherwise, replace the thermostat.
4. Make sure the valve is held closed by a spring when the thermostat is cold. Otherwise, replace the thermostat.
Installing a thermostat
1. Install the thermostat in the cavity of the inlet pipe on a new gasket.
(3S-FE, 4S-FE)
A) Install a new gasket on the thermostat.
b) Align the thermostat bypass valve with the tab and insert the thermostat.
Note: The bypass valve can be installed within 5°to either side of the prescribed position.
(ZS-T)
A) Install a new gasket on the thermostat, then install the thermostat in the block with the bypass valve opening facing up.
2. Install the coolant inlet fitting with two nuts and bolts.
- Tightening torque - 9 Nm
3. Fill the system with coolant (see section "Maintenance and general inspection and adjustment procedures").
4. Start the engine and check for coolant leaks.