Mechanics

TOYOTA SIENNA THERMOSTAT PROBLEM

1999 Toyota Sienna • 192,000 miles

Where is the thermostat location on my engine?
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Guest
November 10, 2012.




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.

DRAIN ENGINE COOLANT
REMOVE AIR CLEANER CAP WITH AIR CLEANER HOSE
DISCONNECT ECT SWITCH CONNECTORS

DISCONNECT ENGINE WIRE PROTECTOR FROM WATER INLET AND RH CYLINDER HEAD Remove the 2 nuts, and disconnect the engine wire protector from the water inlet and cylinder head.

DISCONNECT WATER INLET PIPE FROM WATER INLET AND LH CYLINDER HEAD

Remove the bolt, and disconnect the inlet pipe from the water inlet.
Remove the O-ring from the inlet pipe.

REMOVE WATER INLET AND THERMOSTAT

Remove the 3 nuts, water inlet and thermostat.
Remove the gasket from the thermostat.

INSPECTION
INSPECT THERMOSTAT

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

Immerse the thermostat in water and gradually heat the water.
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.

Check the valve lift. Valve lift: 10.0 mm (0.394 inch) or more at 95°C (203°F)

If the valve lift is not as specified, replace the thermostat.

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

PLACE THERMOSTAT IN WATER PUMP

Install a new gasket on to the thermostat.
Align the thermostat jiggle valve with the upper stud bolt, and insert the thermostat in the water inlet housing.

HINT: The jiggle valve may be set within 15°of either side of the prescribed position.

INSTALL WATER INLET Install the water inlet with the 3 nuts.

Torque: 8 Nm (80 kgf. Cm, 69 inch lbs.)

INSTALL WATER INLET PIPE

Install a new O-ring to the water inlet pipe.
Apply soapy water to the O-ring.
Connect the water inlet pipe to the water inlet.
Install the bolt holding the water inlet pipe to the cylinder head. Torque: 19.5 Nm (200 kgf. Cm, 14 ft. Lbs.)

INSTALL ENGINE WIRE PROTECTOR
CONNECT ECT SWITCH CONNECTORS
REINSTALL AIR CLEANER CAP WITH AIR CLEANER HOSE
FILL WITH ENGINE COOLANT
START ENGINE AND CHECK FOR LEAKS
RECHECK ENGINE COOLANT LEVEL


ASEMaster6371
Nov 10, 2012.
This is a V6 you didn't say engine size.
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Hmac300
Nov 10, 2012.

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