Checking the cooling system
At the first signs of overheating, if the arrow of the temperature gauge has gone into the red zone, but there are no puffs of steam coming out from under the hood, fully open the heater valve and the air intake control air damper, turn on the heater electric motor at maximum speed.
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 other than knocking out liquid 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 "heat stroke".
Stop the engine. Please note that an overheated engine cannot immediately stop after the ignition is turned off and continues to work due to the so-called pseudo-glow ignition. Such work is harmful to the engine, so you should stop it forcibly, or gently pressing the pedal to the floor "gas", or by shifting into any gear with the clutch depressed, then applying the brake and releasing the clutch.
1. Open the hood and inspect the engine compartment. Determine where the steam is coming from.
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 scald you. If you want to open the radiator cap on a hot engine, first put a thick thick rag on top and only then carefully turn the cap.
2. 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 front floor mats in the car for leaks or traces of coolant flowing from the radiator or heater tap.
Found a leak?
No: see point 5.
4. A broken 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 an overheated engine. Let the engine cool down with the hood open for at least 30 minutes.
5. While the engine is warm, turn on the ignition and check that the cooling fan is spinning.
Are the fan blades spinning?
Yes: see point 13.
6. Check if the sensor that turns on the fan motor is good. To check, remove two wires from the terminals of the sensor installed in the radiator and connect them together. Turn on the ignition.
Are the fan blades spinning?
No: see point 8.
7. Bring the liquid level in the cooling system to normal, insulate the wire lugs so that they do not short to "mass". The fan motor will run constantly. This is acceptable for some time, but as soon as possible, replace the sensor in the radiator with a serviceable one, and the antifreeze diluted with water with a new one, since the freezing temperature of such "cocktail" much higher.
8. If the fan does not turn on when the wires leading to the sensor are shorted, then the reasons may be a blown fuse, a faulty turn-on relay, or a burnt out electric motor. Replace fuse #5 (mounting block type 2114-3722010-60) or #4 and 8 (mounting block type 17.3722).
Tip: Fuse numbers can be checked by the designations on the cover of the mounting block.
To check the result of the replacement, short the two wires connected to the fan on sensor and turn on the ignition.
Did the electric motor work?
No: see point 10.
9. Bon Voyage!
10. To test the motor, take two extra wires and power 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 onto the engine, and the directions of the generated air flow and the incoming (track) flows matched.
Did the electric motor work?
No: see point 12.
11 Contact a car service to check the wiring or replace the relay for turning on the cooling fan.
12. Contact a car service to check the wiring or replace the cooling fan motor.
13. 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).
14. To check the thermostat, on a warm engine, check the temperature of the upper and lower hoses connecting the engine to the radiator by touch. If the lower radiator hose is cold, the thermostat is faulty and there is no circulation through the radiator.
Adviсe
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). At the same time, the boiling point of water rises to 120°C, and of antifreeze 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.
It is obvious that if, on an overheated engine, remove the plug of the expansion tank and in time this action will coincide 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. This partially restores the efficiency of the radiator.