Diesel Data: Automotive Repair

Thermostat: Service and Repair






REMOVAL

HINT: Removal of the thermostat would have an adverse effect, causing a lowering of cooling efficiency. Do not remove the thermostat, even if the engine tends to overheat.

1. DRAIN ENGINE COOLANT





2. REMOVE WATER INLET AND THERMOSTAT
a) Disconnect the wire harness clamp from the water inlet.
b) Remove the 2 nuts, and disconnect the water inlet from the cylinder block.
c) Remove the thermostat.
d) Remove the gasket from the thermostat.

INSPECTION
INSPECT THERMOSTAT





HINT: The thermostat is numbered with the valve opening temperature.





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





c) Check the valve lift.
Valve lift: 8.5 mm (0.345 inch) or more at 93°C (199°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 40°C (104°F)).
If not closed, replace the thermostat.

INSTALLATION





1. PLACE THERMOSTAT IN CYLINDER BLOCK
a) Install a new gasket to the thermostat.
b) Install the thermostat with the jiggle valve upward.

HINT: The jiggle valve may be set within 10° at either side of the prescribed position.

2. INSTALL WATER INLET
a) Install the water inlet with the 2 nuts.
b) Install the wire harness to the water inlet.
Torque: 9.0 Nm (90 kgf-cm, 80 inch lbs.)
3. FILL WITH ENGINE COOLANT
4. START ENGINE, AND CHECK FOR COOLANT LEAKS.