In the instrument cluster of any car there is a coolant temperature gauge. If the engine overheats, the coolant temperature gauge needle approaches the red zone.
Checking the cooling system
At the first sign of overheating, if the arrow of the temperature gauge has gone into the red zone, but no clouds of steam escape from under the hood, turn on the maximum interior heating mode (see «Heating and ventilation»). This is necessary in order to reduce the temperature of the coolant in the engine cooling system.
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 bursts or jumps off or another leak occurs, in addition to the release of fluid from under the expansion tank plug, the engine will have to be turned off immediately! After the overheated engine stops, local overheating of the coolant begins at the points of its contact with the most heat-stressed engine parts and the formation of vapor locks. This phenomenon is called thermal shock.
1. Stop the engine.
2. Open the hood on the car 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 integrity of the rubber hoses, radiator, thermostat.
3. Look under the instrument panel on the front passenger side - if there are any leaks or traces of coolant flowing from the heater radiator under it.
If a coolant leak is detected, the burst hose can be temporarily repaired with adhesive tape.
A leak in a radiator, thermostat or heater 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 replenishing the level in the cooling system.
Attention! 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.
4. If there is no coolant leak, check the fan motor fuse and relay, see «Electronic engine management system (fuel injection systems)».
5. In a car, the engine can overheat if the thermostat that controls the flow of coolant 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 thermostat to the radiator. If the lower radiator hose is cold, the thermostat is bad and there is no circulation through the radiator.
6. 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. If it does not turn on, the fuse may have blown, the turn-on relay is faulty, or the electric motor has burned out.
7. Replace the F5 fuse in the fuse and relay box. If the fan still does not start after replacing the fuse, check the cooling fan motor by taking two additional wires and powering the motor directly from the battery. Wires must be securely fastened and insulated.
8. If the cooling fan motor starts to work, the wiring or the cooling fan relay 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»).
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.