Thermostat for cars with 4G9 and 4G1 engines, F9Q1

Thermostat for vehicles with 4G9 and 4G1 engines

Note. Disassembly of the thermostat can lead to malfunction and reduce the efficiency of the engine cooling system.

Removing

• Disconnect the wire from the negative battery terminal.
• Drain the coolant from the cooling system.
• Remove the air filter.
• Mark the hose and clamp, loosen the clamp and disconnect the hose from the thermostat housing inlet (pic. 5.10).
• Turn out bolts and remove an inlet branch pipe and the thermostat.

Pic. 5.10. Thermostat for vehicles with 4G9 and 4G1 engines: 1 - hose; 2 - an inlet branch pipe of a casing of the thermostat; 3 - thermostat

Examination

• Hang the thermostat on a thread in a transparent vessel with water (pic. 5.11). Insert a thermometer into the water, heat a vessel of water and observe the thermostat valve. Determine the temperature of the start of opening and full opening of the thermostat valve.

Pic. 5.11. Heating thermostat in a transparent vessel with water

• Check the opening stroke of the thermostat valve at its maximum opening (pic. 5.12). To measure the valve travel, measure the distance from the bottom of the valve to the thermostat housing when the latter is fully closed and then fully open, and then calculate the valve travel.

Pic. 5.12. Place of measurement of thermostat valve travel

Installation

• Installation is carried out in the reverse order of removal, taking into account the following.
• Install the thermostat so that its air valve is on top, while not damaging the rubber seal of the thermostat (pic. 5.13).

Pic. 5.13. Thermostat installation position on vehicles with petrol engines

Warning. Make sure the thermostat rubber seal is free of engine oil or grease. Also, when installing, do not bend or scratch the thermostat rubber seal.

• Push the hose onto the nozzle so that its end reaches the protrusion on the nozzle.
• Secure the hose with a clamp, while matching the marks on the hose and clamp.
• Pour coolant into the cooling system.
• Connect the wire to the negative battery terminal.
• Start the engine and check for leaks from the cooling system.

F9Q1 diesel car thermostat

Note. Disassembly of the thermostat can lead to malfunction and reduce the efficiency of the engine cooling system.

Removing

• Disconnect the wire from the negative battery terminal.
• Drain the coolant from the cooling system.
• Remove the air filter.
• Mark the hose and clamp, loosen the clamp and disconnect the hose from the thermostat housing inlet (pic. 5.14).

Pic. 5.14. F9Q1 diesel car thermostat: 1 - upper radiator hose; 2 - branch pipe of the thermostat housing; 3 - gasket; 4 - sealing ring; 5 - thermostat; 6 - hose of the cooling system; 7 - lower radiator hose; 8 - heater hoses; 9 - thermostat casing; 10 - sealing ring; 11 - screw for removing air from the cooling system; 12 - clamp; 13 - coolant temperature sensor; 14 - sealing ring; 15 - cork; 16 - sealing ring

• Turn out bolts and remove a branch pipe of a casing of the thermostat, a lining, a sealing ring and the thermostat.
• Loosen the clamp and disconnect the coolant hose from the thermostat housing.
• Mark the hose and clamp, loosen the clamp and disconnect the hose from the thermostat housing.
• Disconnect the connector from the coolant temperature sensor.
• Remove the clip and coolant temperature sensor and O-ring.
• Loosen the clamps and disconnect the heater hoses from the thermostat housing.
• Turn out bolts and remove a casing of the thermostat and a sealing ring.

Installation

• Installation is carried out in the reverse order of removal, taking into account the following.
• When installing, replace all O-rings with new ones.
• Push the hoses onto the nozzles so that their ends reach the protrusions on the nozzles.
• Secure the hoses with clamps, while matching the marks on the hoses and clamps.
• Pour coolant into the cooling system.
• Install the air filter.
• Connect the wire to the negative battery terminal.
• Start the engine and check for leaks from the cooling system.