Note: If the engine is constantly overheating, removing the thermostat will not bring positive results. The cause of overheating should be found and eliminated.
Removing the thermostat
1. Drain the coolant (see relevant paragraph).
2. Remove the inlet by removing the three bolts and gasket from the inlet body.
3. Remove the thermostat.
Engine 2L, 3L
Engine 2L-T
Engine 1KZ-T: 1 - thermostat, 2 - gasket, 3 - inlet pipe.
Engine 1KZ-T
Thermostat check
Note: The thermostat has a digital characteristic corresponding to the opening temperature of the valve.
1. Immerse the thermostat in water and gradually heat it up.
2. Check the valve opening temperature.
Valve opening temperature
- engines 2L, 3L - 86-90°С
- motors 1KZ-T - 80-84°C
If the valve opening temperature is not within the specified limits, replace the thermostat.
3. Check valve lift.
Valve lift at 100°C:
- motors 2L, 3L - not less than 10 mm
- motors 1KZ-T, 2L-T - not less than 8 mm
If the valve lift is not within the specified limit, replace the thermostat.
4. Check the stiffness of the valve spring when the thermostat is fully closed.
If necessary, replace the thermostat.
Installing a thermostat
1. Place the thermostat in the inlet housing with the vent facing up.
2. Install a new gasket and inlet pipe by tightening the three bolts. Tightening torque 13 N.m.
3. Fill in coolant.
4. Start the engine and check for leaks.
Troubleshooting
Symptom | Possible reason | Remedy |
The engine gets very hot | The fan belt is loose or missing. Dirt, on the radiator or air conditioner condenser. Leak in hoses, water pump, thermostat housing, radiator, heater, core plugs, or head gasket. Thermostat failure. Late fuel injection. Hydraulic clutch failure. Radiator hose clogged or damaged. Water pump malfunction. Clogged radiator or defective filler cap Cracks or blockage in the cylinder head or block | Adjust or replace belt. Clean the radiator or condenser. Make the necessary repairs.
Check thermostat. Adjust fuel injection. Replace viscous coupling. Replace hose. Replace water pump. Check the radiator. Make the necessary repairs. |