2. Open the hood and inspect the underhood space. Determine where the steam is escaping from. When inspecting the engine, pay attention to the presence of coolant in the expansion tank, the condition of the rubber hoses of the engine cooling system, as well as the condition of the radiator and thermostat.
Warning! Never open the expansion tank cap immediately. The liquid in the cooling system is under pressure, when you open the cap the pressure will drop sharply, the liquid will boil and its splashes can scald you. If you want to open the expansion tank cap on a hot engine, first put a thick, dense rag on top and only then carefully unscrew the cap.
3. Look underneath instrument panel - are there any traces of coolant leaking from the radiator or heater tap underneath it?.
If coolant leaks are detected, a burst hose can be temporarily repaired using adhesive tape. A radiator, thermostat or heater leak is quite difficult to fix on the spot, so in such a situation it is necessary to add water to the cooling system and carefully monitor the temperature gauge while driving, periodically restoring the level in the cooling system.
Warnings! Long-term use of water instead of antifreeze leads to scale formation in the engine cooling system, deterioration of its cooling and, as a result, reduction of service life.
Never add cold water to overheated engine. The engine must cool down with the hood open for at least 30 minutes.
4. If there is no coolant leak, check the integrity of fuse #5 (20 A). It protects the power supply circuit of the electric fan of the cooling system and is located in the fuse and relay mounting block installed in the engine compartment. If the electric motor starts working after replacing the fuse, you can continue driving.
5. If the electric motor does not work even after replacing the fuse, take two additional wires and supply power to the electric motor directly from the battery to check. The wires must be securely fastened and insulated.
Warnings! Do not allow wires to short-circuit each other!
Pay attention to the polarity of the connection: the electric motor must rotate so that the fan forces air through the radiator onto the engine, and the directions of the generated air flow and the incoming (path) flow coincide.
If the electric motor starts working, the wiring or the relay for turning on the cooling system fan, located on the right side of the instrument panel console under the trim, is faulty. If not, the wiring or the electric motor itself is also faulty. The relay and the electric motor cannot be repaired, replace them as a whole (see section "Electrical equipment").**
6. The engine may overheat if the thermostat, which regulates the flow of fluid in the cooling system through or past the radiator, fails (to speed up the warming up of a cold engine). To check the thermostat, you need to check the temperature of the lower hose connecting the engine to the radiator on a warm engine. If the lower radiator hose is cold, the thermostat is faulty, there is no circulation through the radiator.
The expansion tank plug valve plays a major role in ensuring the optimal temperature regime. It maintains excess pressure in the system of at least 0.1 MPa (1.1 kgf/cm²). The boiling point of water rises to 120°C, and antifreeze to 130°C. Unfortunately, when the valve gets stuck in the closed position due to overheating, a significant excess of pressure occurs [more than 0.2 MPa (2 kgf/cm²)], which can lead to a rupture of the expansion tank or a tear in one of the hoses.
Therefore, once a year, the expansion tank cap should be washed with running water, and the valve should be checked for sticking by pressing with a finger. If in doubt, replace the cap. Obviously, if you remove the expansion tank cap on an overheated engine and this action coincides with the "thermal shock", boiling of the liquid and the formation of air locks in the cooling system will be guaranteed.
Once a year, flush the radiator cells with a high-pressure water jet (at a special car wash), directing the stream first towards the oncoming air flow, and then in its direction to remove dirt, stuck insects and road debris from the radiator surface. This can partially restore the radiator's efficiency.