Turn on the hazard warning lights, depress the clutch pedal and, using the momentum of the car, try to carefully move to the edge of the roadway and stop as far to the right as possible at the curb, and if possible, outside the roadway. Let the engine run for a couple of minutes at normal idle with the heater on at full power.
Attention! Do not stop the engine immediately! The only condition is to maintain the tightness of the cooling system. If a hose has burst or jumped off or another leak has formed, in addition to the ejection of fluid from under the expansion tank plug, the engine will have to be stopped immediately!
After the overheated engine stops, local overheating of the coolant begins at the points of contact with the most heat-stressed engine parts and the formation of vapor locks. This phenomenon is called thermal shock.
1. Stop the engine.
Pic. 3.2. Places for inspection in the engine compartment
2. Open the hood and inspect the engine compartment (pic. 3.2). Determine where the steam is coming from. When inspecting the engine, pay attention to the presence of coolant in the expansion tank, the integrity of the rubber hoses, radiator, 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.
Note. 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). In this case, the boiling point of water rises to 120°C, and of the coolant - up to 130°C. Unfortunately, when the valve is stuck in the closed position during overheating, a significant excess of overpressure occurs - more than 0.2 MPa (2 kgf/cm2), which can lead to a rupture of the expansion tank or a breakdown of one of the hoses.
Therefore, once a year, the plug of the expansion tank must be washed with running water. If in doubt, replace the plug. Obviously, if the plug of the expansion tank is removed on an overheated engine and this action coincides with thermal shock in time, 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 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. In this way, the efficiency of the radiator can be partially restored.
Note. If coolant leaks are found, the burst hose can be temporarily repaired with adhesive tape. Especially well suited for this purpose reinforced (usually silver in color) adhesive tape, which can be purchased at car dealerships.
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.
Attention! Long-term use of water instead of coolant leads to the formation of scale in the engine cooling system, deterioration of its cooling and, as a result, a reduction in the resource.
Attention! Never add cold water to an overheated engine. The engine must cool down with the hood open for at least 30 minutes.
3. 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 the temperature of the hose connecting the thermostat housing to the radiator by touch. If the hose is cold, the thermostat is faulty and there is no circulation through the radiator.
4. Very often, the cause of overheating of the engine, the cooling system of which is equipped with an electric fan, is the failure of the fan. Start the engine, monitor the temperature and note if the cooling fan turns on when the engine overheats.
5. If the fan does not turn on, the fuse may have blown, the turn-on relay is faulty, the electric motor is burnt out, or the wiring is faulty.
6. Check the integrity of the wiring, the reliability of the connection of the electrical connectors.
7. If the wiring is OK, check the fuse for the engine cooling fan and replace it if faulty.
8. If the fuse is good, try replacing the fan relay.
9. If the fan still does not turn on, check the motor. To do this, take two additional wires and power it directly from the battery. Wires must be securely fastened and insulated.
Attention! Do not allow wires to short circuit with each other!
Attention! 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.
10. If the electric motor started to work, the wiring is faulty; if not, the wiring or the motor itself is also faulty. Relay and motor not repairable, replace as an assembly (see sect. «electrical equipment»).
Note. It is allowed to get to the place of repair with an electric motor connected directly to the battery. Upon arrival, do not forget to disconnect the electric motor from the battery, otherwise it will lead to its discharge.