Overheating of the engine of the car Skoda Octavia

When the engine of a Skoda Octavia car is running, a working cooling system maintains an optimal temperature regime. Malfunctions in the cooling system can lead to overheating of the car engine. If you miss this moment, unpleasant consequences can penetrate: breakdown of the head gasket, warping of the head and, as a result, complex engine repairs. In the instrument cluster of any car there is a coolant temperature gauge. If the engine overheats, the pointer needle approaches the red zone.
Checking the car engine cooling system in case of overheating
At the first signs of overheating, if the arrow of the pointer has gone into the red zone, but no clouds of steam escape from under the hood, turn on the maximum interior heating mode. This is necessary in order to reduce the temperature of the coolant in the engine cooling system.
Turn on the hazard warning lights and, using the car'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, outside the roadway. Let the engine run for a couple of minutes at normal idle speed with the heater on at full power.
WARNING
Do not stop the engine immediately if it overheats! 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, the integrity of the rubber hoses, radiator, thermostat.
GOOD ADVICE
If a coolant leak from a hose is detected when the car engine overheats, the burst hose can be temporarily repaired with adhesive tape. Reinforced adhesive tape, which can be purchased at car dealerships, is especially suitable for this purpose.
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 turn the cap.

3. Look under the mats on the driver and front passenger side and determine if there are any traces of coolant flowing from the heater radiator under them.
When a car engine overheats, it is rather difficult to eliminate a leak in a radiator, thermostat or heater on the spot, therefore, 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.
WARNING
Never add cold water to an overheated engine. The engine must cool down with the hood open for at least 30 minutes.

4. The car engine can overheat if the thermostat fails, which controls the flow of fluid in the cooling system through the radiator or inside the cylinder block (to accelerate the warm-up of a cold engine). To check the thermostat, on a warm engine, check the temperature of the lower hose connecting the radiator to the engine by touch. If the lower radiator hose is cold, the thermostat is bad and there is no circulation through the radiator.

5. Very often, the cause of overheating of a car engine is the failure of one or both electric fans.
Start the engine, monitor the temperature and note if the cooling fans turn on when the engine overheats. If one of the fans does not turn on, then the reasons may be a blown fuse, oxidized contacts in the wiring harness block, or a burned out electric motor.

6. Check the power fuse A. installed on the front wall of the mounting block in the engine compartment ...

7. ... and fuse B in the mounting block. Replace the blown fuse if necessary.
If the fan does not start after changing the fuses, check the motor by taking two additional wires and powering it directly from the battery. Wires must be securely fastened and insulated.
WARNING
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, and the directions of the generated flow and the oncoming (track) air flow coincide.
If the Skoda Octavia electric motor started to work, the wiring is faulty; if not, the wiring or the motor itself is also faulty. The electric motor is not repairable, replace it as an assembly.
USEFUL ADVICE
There are two valves in the plug of the expansion tank - inlet and outlet. The exhaust valve plays a big role in ensuring the optimal temperature regime of the engine. It maintains an excess pressure of at least 0.13-0.15 MPa (1.3-1.5 kgf / cm2) in the system, providing an increase in the temperature at which the coolant begins to boil and preventing intense vaporization. When the valve is jammed in the closed position during overheating, a significant excess of excess pressure 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 will be guaranteed.
Once a year, blow out the radiator cells with a jet of compressed air (for example, 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.

Source: http://skoda-octavia2.ru/index.php/neispravnosti-skoda-octavia/42-peregrev-dvigatelya-avtomobilya.html