1998 Lexus GS 300

1998 Lexus GS 300 900000 miles

Where is the thermostat located on a 1998 Lexus GS 300 and how is it replaced?
April 27, 2010.

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.Disconnect water inlet from water pump, and remove thermostat.
a.Remove the 2 nuts holding the water inlet to the water pump, and disconnect the water inlet from the water pump.
b.Remove the thermostat.
c.Remove the gasket from the 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 lift is not as specified, replace the thermostat.
c.Check the valve lift. Valve lift: 8.5 mm (0.335 inch) or more at 95 °C (203 °F) If the valve lift is not as specified, replace the thermostat.
d.Check that the valve is fully closed when the thermos is at low temperatures (below 40 °C (104 °F)). If not closed, replace the thermostat.

1.Place thermostat in water inlet.
a.Install a new gasket to the thermostat.
b.Align the jiggle valve of the thermostat with the protrusion of the water inlet.
2.Install water inlet. Install the water inlet with the 2 nuts. Torque: 9.0 Nm (80 inch lbs.)
3.Fill with engine coolant.
4.Start engine and check for coolant leaks radiator

Apr 28, 2010.