The thermostat in the car VAZ 2109 is the most important element of the cooling system, which with a valve regulates the flow of coolant flow and provides warm up the car, the timely removal of excess heat from hot parts and protect the engine from overheating.

Thermostat diagnosis in the home

For home thermostat test car VAZ 2109 requires prior dismantling of parts of engine. All work must be performed on a cold car, because there is a risk of severe burns. Before removing the thermostat it is necessary to disassemble the crankcase and to completely drain from the cooling system antifreeze after diagnostics it can be reused. To drain the antifreeze you first need to open the surge tank cap, and then to substitute pre-prepared fluid drainage container under the engine block. Opening the drain plug to drain the antifreeze. Then place a container under the drain hole of the radiator by unscrewing the plug on it to drain all the coolant.

After draining the antifreeze need to loosen the tightening clamps and disconnect a few pipes from the thermostat housing: the hose from the surge tank outlet hose from the radiator, the hose from the pipe to the pump and the hose connecting the thermostat with the engine. Gently removing the thermostat, first undergoes a visual diagnosis of the main valve details: it can jam in the open position, which causes a malfunction of the thermostat.

If the valve is closed, the diagnosis operation of the thermostat 2109 is performed by using a slowly heated water containers. The thermostat is immersed in a container along with a thermometer and gradually heating the water, place the beginning of the operation of the valve and the temperature level of this point.

Normal operating temperature of the thermostat of the car VAZ 2109 is considered to be 87 degrees Celsius, allowed level of error of no more than 2-3 degrees. A properly working thermostat will gradually open the valve as you raise the temperature of the liquid flowing of the water in the main pipe. When the temperature reaches 108-110 degrees, the thermostat valve should open completely and reset the heated water in the circuit cooler. As the cooling out of water the thermostat should fully close the valve.

Diagnosis of the thermostat directly on the car

Check the thermostat on the car is when the engine is cold. After starting the motor, you must verify to touch the outlet nozzle from the radiator. The norm is the lack of heat the pipe until then while the sensor is the coolant temperature on the instrument panel will not show warm up to 80-90 degrees.

If the tube heats up before that time, we can assume the malfunctioning valve, leading to longer engine warm-up time and a significant increase in fuel consumption. If the tube remains cool at high temperatures of the coolant, the reason may lie in the jamming of the valve. In this case, you need to replace the thermostat.