Nissan Sentra Service Manual: Thermostat and thermostat housing

Exploded View

1. Thermostat housing
2. Gasket
3. Rubber ring
4. Thermostat
5. Water inlet
6. Clamp
7. Radiator hose (upper)

1. To radiator

WARNING:

Do not remove the radiator cap when the engine is hot. Serious burns could occur from high-pressure engine coolant escaping from the radiator. Wrap a thick cloth around the cap. Slowly push down and turn it a quarter turn to allow built-up pressure to escape. Carefully remove the cap by pushing it down and turning it all the way.

NOTE:

When removing components such as hoses, tubes/lines, etc., cap or plug openings to prevent fluid from spilling.

Removal and Installation of Thermostat

REMOVAL

1. Remove engine under cover. Refer to EXT-16, "Exploded View".
2. Drain engine coolant from radiator. Refer to CO-12, "Changing Engine Coolant".

CAUTION:

• Perform this step when the engine is cold.

• Do not spill engine coolant on the drive belt.

3. Disconnect radiator hose (lower) from water inlet side. Refer to CO-15, "Exploded View".
4. Remove water inlet bolts, then remove water inlet and thermostat.

Inspection after removal

• Place a thread (A) so that it is caught in the valves of the thermostat (1). Immerse fully in a container (B) filled with water. Heat while stirring.
• The valve opening temperature is the temperature at which the valve opens and the thermostat falls from the thread.
• Continue heating. Check the full-open lift amount.

NOTE:

The full-open lift amount standard temperature for the thermostat is the reference value.

• After checking the full-open lift amount, lower the water temperature and check the valve closing temperature.

• If valve setting at measured values are out of standard range, replace thermostat.

Installation

Installation is in the reverse order of removal.

• Install the thermostat with the whole circumference of the flange (A) fitting securely inside the rubber ring (1).

CAUTION:

Do not reuse rubber ring.

• Install the thermostat (2) into the thermostat housing (1) with the jiggle valve (A) facing upwards. The position deviation may be within the range of В±10В°.
• After installation, refill engine coolant and check for leaks. Refer to CO-12, "Changing Engine Coolant" and CO-11, "System Inspection".

Removal and Installation of Thermostat Housing

REMOVAL

1. Remove the generator. Refer to CHG-29, "Removal and Installation".
2. Partially remove the fender protector (LH). Refer to EXT-28, "FENDER PROTECTOR : Removal and Installation - Front Fender Protector".
3. Remove the thermostat housing bolts, then remove the thermostat housing.
4. Remove thermostat if necessary. Refer to CO-21, "Removal and Installation of Thermostat".
5. Remove water pump if necessary. Refer to CO-19, "Removal and Installation".

INSTALLATION

Installation is in the reverse order of removal.

CAUTION:

• Do not reuse gasket

• Do not spill engine coolant on the drive belt.

Inspection

INSPECTION AFTER INSTALLATION

After installation, refill engine coolant and check for leaks. Refer to CO-11, "System Inspection" and CO-12, "Changing Engine Coolant".