The thermostat may need to be removed to replace it if the engine temperature is unstable - overheating or insufficient heating

In this case, it is not necessary to completely drain the coolant.

To check the thermostat on the car, start the engine and touch the lower radiator hose with your hand - it should be cold.

After the coolant temperature reaches 80-85 ° C, the hose should begin to heat up.

If this does not happen, remove the thermostat and check its functionality.

Thermostat: 1 - water pipe (from the engine); 2 - bypass valve; 3 - bypass valve spring; 4 - cup; 5 - rubber insert; 6 - outlet pipe; 7 - main valve spring; 8 - main valve seat; 9 - main valve; 10 - holder; 11 - adjusting nut; 12 - piston; 13 - outlet pipe (from the radiator); 14 - filler; 15 - collar; D - fluid inlet from the engine; P - fluid inlet from the radiator; H - fluid outlet to the pump

Thermostat failure is associated with the jamming of the thermal valve.

The thermal valve can jam in the open position, and the engine will take a long time to warm up.

The thermal valve can jam in the closed position, and the engine will overheat.

The thermostat should only be removed when the engine has completely cooled down.

You will need a screwdriver.

Drain some of the coolant by unscrewing the plug from the hole for draining the liquid in the cylinder block (see "Replacing the cooling liquid Niva Chevrolet").

How to replace the thermostat Niva Chevrolet

Use a screwdriver to loosen the clamp securing the radiator outlet hose

How to replace the thermostat Niva Chevrolet

Remove the hose from the thermostat pipe

How to replace the thermostat Niva Chevrolet

Loosen the clamp securing the outlet hose of the throttle assembly heating unit, and remove the hose from the thermostat pipe.

Depending on the engine configuration, the thermostat may differ in design.

If the throttle assembly with an electronic damper drive, the pipe for heating the throttle assembly is closed.

How to replace the thermostat Niva Chevrolet

And the heating hose does not come off it throttle assembly (Fig. 5).

How to replace the thermostat Niva Chevrolet

Loosen the clamp securing the bypass hose and remove it from the thermostat pipe.

Loosen the clamp securing the outlet hose of the heater radiator to the thermostat pipe and remove the hose.

How to replace the thermostat Niva Chevrolet

Loosen the clamp securing the coolant supply hose to the pump

How to replace the thermostat Niva Chevrolet

Remove the thermostat.

Before installation, check the thermostat by placing it in water heated to 70-75 °C.

How to replace the thermostat Niva Chevrolet

Heat the water, stirring it constantly, to (80±2)°С.

At a temperature of (80±2)°С, the main thermostat valve should begin to open.

If this does not happen, replace the thermostat.

Install the new thermostat in the reverse order of removal.

To eliminate the possibility of coolant leakage in the future, Before installation, lubricate the thermostat pipes with a thin layer of silicone sealant.

 Fill in the coolant and remove air locks from the cooling system (see "Replacing the Niva Chevrolet Coolant").