2. Open the hood and inspect the engine compartment. Determine where the steam is coming 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 the plug is opened, the pressure will drop sharply, the liquid will boil and its splashes can scald you. If you want to open the cap of the expansion tank on a hot engine, first put a thick thick rag on top and only then carefully unscrew the cap.
3. Look under dashboard - are there any traces of coolant under it, flowing from the radiator or heater valve.
If coolant leaks are found, a burst hose can be temporarily repaired with 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! Prolonged use of water instead of antifreeze leads to the formation of scale in the engine cooling system, deterioration of its cooling and, as a result, a reduction in the resource.
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 fuse #5 (20 A). It protects the power supply circuit of the electric fan of the cooling system and is located in the mounting block of fuses and relays installed in the engine compartment. If the motor starts running after replacing the fuse, you can continue driving.
5. If the motor does not run even after changing the fuse, take two additional wires for testing and apply power to the motor directly from the battery. Wires must be securely fastened and insulated.
Warnings! Do not allow wires to short circuit with each other!
Pay attention to the polarity of the connection: the electric motor must rotate so that the fan blows air through the radiator onto the engine, and the directions of the generated air flow and the incoming (track) flows matched.
If the electric motor starts running, the wiring or the relay for turning on the cooling fan located on the right side of the instrument panel console under the trim is faulty. If not, the wiring or the motor itself is also faulty. Relay and motor not repairable, replace as an assembly (see section «electrical equipment»).**
6. The engine can overheat if the thermostat that controls the flow of fluid in the cooling system through or past the radiator fails (to accelerate the warm-up of a cold engine). To check the thermostat, on a warm engine, check by touch the temperature of the lower hose connecting the engine to the radiator. If the lower radiator hose is cold, the thermostat is bad and there is no circulation through the radiator.
The expansion tank plug valve plays an important role in ensuring optimal temperature conditions. It maintains an excess pressure of at least 0.1 MPa in the system (1.1 kgf/cm2). The boiling point of water rises to 120°C, and antifreeze - up to 130°C. Unfortunately, when the valve is stuck in the closed position during overheating, a significant overpressure occurs [more than 0.2 MPa (2 kgf/cm2)], which may cause the expansion tank to rupture or one of the hoses to break.
Therefore, once a year, the cap of the expansion tank must be washed with running water, and the valve checked for sticking by pressing a finger. If in doubt, replace the plug. Obviously, if the plug of the expansion tank is removed on an overheated engine and this action coincides in time with «heat stroke», liquid boiling and the formation of air pockets in the cooling system will be guaranteed.
Once a year, flush the radiator cells with a high-pressure water jet (at a special sink), directing the jet first towards the oncoming air flow, and then in its direction to remove dirt, adhering insects and road debris from the surface of the radiator. So you can partially restore the efficiency of the radiator.