SOHC Engine Thermostat

SOHC Engine Thermostat

1 – bolt, 15–20 N·m;
2 – coolant outlet fitting;
3 – gasket;
4 – thermostat;
5 – thermostat housing.

Removal

PROCEDURE

1. Drain the coolant to a level below the thermostat.
2. Remove the coolant outlet fitting and the gasket.
3. Remove the thermostat.

Inspection

PROCEDURE

1. Visually inspect the thermostat.
2. Suspend the thermostat by a string in a transparent container filled with water.

3. Immerse a thermometer in the water, heat the container and observe the thermostat valve. Determine the temperature at which the valve begins to open and the temperature at which it is fully open.

Thermostat valve begins to open: 82°C.
Thermostat valve fully open: 95 °C.
Thermostat valve lift: 8.0 mm

Installation

PROCEDURE

1. Install the thermostat so that the air bleed valve is correctly positioned in the seat. If the thermostat is installed in the wrong position, the thermostat base will contact the rib in the intake manifold, which will impair its operation.
2. Install a new gasket and the coolant outlet fitting.
3. Fill the cooling system with the required amount of specified coolant. Start the engine and check the cooling system for leaks.