The vehicle's instrument cluster contains a coolant temperature gauge. If the engine overheats, the pointer needle approaches the H zone.
Checking the cooling system
At the first sign of overheating, if the arrow of the temperature gauge has gone into zone H, but no clouds of steam escape from under the hood, turn on the maximum interior heating mode (ohm. «Heating, air conditioning and ventilation system»). 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, then using the vehicle's momentum, 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, out of the roadway. Let the engine run for a couple of minutes at normal idle speed, with the heater turned on at full power,
Warning: 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 cap, the engine will have to be stopped 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 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 1 (pic. 3.2), for the integrity of rubber hoses, radiator 2 and thermostat 3.
Warning: Never open the cap of the expansion tank 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 burn 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 turn the cap.
3. Through the hole in the front end shield, a hose is passed into the engine compartment, connected to a tray installed under the heater radiator. If coolant flows out of the hose hole, the radiator is damaged.
If a fluid leak is detected, the burst hose can be temporarily repaired with adhesive tape.
Helpful Hint: Reinforced steel is especially suitable for this purpose (e.g. silver) adhesive tape, which can be purchased at car dealerships.
A radiator, thermostat or heater leak is quite difficult to fix on the spot, therefore, in such a situation, it is necessary to add water to the cooling system and, while driving, carefully monitor the temperature gauge, periodically restoring the level in the cooling system,
Warnings: Long-term 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, to a reduction in the resource.
Never add cold water to an overheated engine. The engine must cool down with the hood open for at least 30 minutes.
4. 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 upper hose connecting the thermostat to the radiator. If the upper radiator hose is cold, the thermostat is bad and there is no circulation through the radiator.
5. Very often, the cause of engine overheating is the failure of the electric fan.
6. Start the engine, monitor the temperature and note if the cooling fan turns on when the engine overheats. If it does not turn on, then the reasons may be a fuse or fuse blown, oxidation of the contacts in the wiring harness block, or a burnout of the electric motor. Replace fuse #45 and fuse #46 (see «Location of fuses, fuses, relays and their replacement») in the fuse box located in the engine compartment. If the fan does not start after replacing the fuse and fuse, check the motor by taking two additional wires and powering it 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 to the engine.
If the electric motor starts to work, the wiring or the relay for turning on the cooling fan is faulty; if not, the wiring or the motor itself is also faulty. Relay and motor not repairable, replace them (see sect. «electrical equipment»).
Helpful Hints: There are two valves installed in the plug of the expansion tank - inlet and outlet. The exhaust valve plays a big role in ensuring optimum engine temperature. It maintains an excess pressure of at least 0.13-0.15 MPa in the system (1.3-1.5 kgf/cm2), providing an increase in the temperature of the start of boiling of the coolant and preventing intense vaporization. When the valve is jammed in the closed position during overheating, a significant excess of overpressure occurs - more than 0.15 MPa (1.5 kgf/cm2), which can lead to a rupture of the expansion tank or a breakdown of one of the hoses. In turn, the jamming of the valve in the open position leads to premature boiling of the coolant.
Therefore, once a year, rinse the plug of the expansion tank 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, then boiling of the liquid and the formation of air locks in the cooling system are guaranteed.
Blow out the radiator cells with compressed air once a year (e.g. from a compressor), 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.