Installing a thermostat on a car (spare wheel removed): 1 - hose to the expansion tank; 2 - thermostat; 3 - radiator outlet hose; 4 - radiator inlet hose; 5 - hose to the inlet pipe of the water pump.
One of the reasons for the long warm-up of the engine after starting and its overheating during operation is a malfunction of the thermostat.
The thermostat valve should open when the coolant temperature is 85-89°C.
The thermostat is interchangeable with the thermostat of the VAZ-2108 car.
Start the engine and let it idle. Feel the radiator outlet hose with your hand - it should be cold. If the hose gets hot, then the thermostat is defective and needs to be replaced (thermostat valve not closing).
Warm up the engine to approximately 87°C (the coolant temperature gauge needle is approaching the red zone). When the arrow is at a distance of 3-4 mm from the red zone, the hose should begin to heat up. Otherwise the thermostat is defective (thermostat valve does not open) and it needs to be replaced.