3.10.1. Check of the cooling system

At the first signs of an overheat if the arrow of the index of temperature went to a red zone (the alarm lamp of an overheat of the engine lit up), but from under a cowl puffs of vapor do not escape, include the maximum mode of heating of salon, see. "Heating (conditioning) and ventilation of salon". It is necessary to reduce temperature of cooling liquid in the engine cooling system.

Turn on the alarm system, squeeze out a coupling pedal, then, using inertia of the car, try to move carefully to the region of the carriageway and to stop as it is possible more to the right at a roadside and if it is possible, then outside the carriageway. Let's the engine work a couple of minutes at normal rate of rotation of a bent shaft idling, with the heater included at full capacity.

PREVENTION Do not stop the engine at once! The only condition — preservation of tightness of the cooling system. If the hose burst or came off or other place of leak, except emission of liquid from under a stopper of a broad tank was formed, the engine should be stopped immediately.

After a stop of the superheated engine the local overheat of cooling liquid in places of its contact with the most heat-stressed details of the engine and formation of steam traffic jams begins. This phenomenon is called heatstroke.

1. Stop the engine.

2. Open a cowl and examine podkapotny space. Define from where steam escapes. At survey of the engine pay attention to availability of cooling liquid in a broad tank, to an integrity of rubber hoses, a radiator, the thermostat.

PREVENTION Never open a stopper of a broad tank at once. Liquid is in the cooling system under pressure, when opening a stopper pressure will sharply fall, liquid will begin to boil and its splashes can scald you. If you want to open a stopper of a broad tank on the hot engine, previously throw from above with a dense thick rag and only after that carefully turn a stopper.

3. Through an opening in a body front board in podkapotny space the hose connected to the tray established under a heater radiator is passed. If antifreeze follows from an opening of a hose, so the radiator is damaged.

If the leak of cooling liquid is found, the burst hose can be restored temporarily by means of an adhesive tape.

GOOD ADVICE Especially well the adhesive tape which can be got in autoshops is suitable for this purpose reinforced (for example, silvery color).

It is quite difficult to eliminate a leak of a radiator, the thermostat or a heater on the place therefore in such situation it is necessary to add water in the cooling system and at the movement to watch closely the index of temperature, periodically restoring level in the cooling system.

PREVENTIONS Long use of water instead of antifreeze leads to scaling in the engine cooling system, to deterioration in its cooling and, as a result, to reduction of a resource. Never add cold water in the superheated engine. It has to cool down with an open cowl not less than 30 min.

4. The engine can overheat in case of failure of the thermostat which regulates passing of a stream of liquid in the cooling system through a radiator or by it (for acceleration of warming up of the cold engine). For check of the thermostat it is necessary to check on the heated-up engine to the touch temperature of the top hose connecting the thermostat to the engine. If the top hose of a radiator cold, the thermostat is faulty, there is no circulation through a radiator.

5. Very often the reason of an overheat of the engine which cooling system is equipped with the electric fan is failure of the fan.

Fig. 10.2. Numbers of safety locks, fusible inserts and the relay in the assembly block located in podkapotny space of the Chevrolet Lanos car

6. Launch the engine, you watch temperature and pay attention whether join at an engine overheat cooling system fans. If they do not join, then the fused safety lock, faulty relays of inclusion, the oxidized contacts in a block of a plait of wires or the burned-down electric motors can be the reasons. Replace a fusible insert 1 (poses. 4 in fig. 10.2) in the assembly block of safety locks and the relay installed in podkapotny space. If fans after replacement of a safety lock did not begin to work, replace the relay 2, 3 and 4 in the same assembly block. If after replacement of a safety lock and the relay fans did not begin to work, check their electric motors for what take two additional wires and give on them power supply directly from the rechargeable battery. Wires have to be reliably fixed and isolated.

PREVENTION Do not allow short circuit of wires among themselves! Pay attention to polarity of connection: the electric motor has to rotate so that the fan forced air through a radiator on the engine, and the directions of the formed and running (traveling) air of streams coincided.

If the electric motor began to work, the electrical wiring or the relay of turning on of the fan of the cooling system is faulty; if is not present — the electrical wiring or actually the electric motor is also faulty. The relay and the electric motor are not maintainable, replace them (see section 10 "Electric equipment").

USEFUL TIPS In a stopper of a broad tank two valves are installed: inlet and final. The final valve plays a large role in providing optimum temperature condition of the engine. It supports the excessive pressure not less than 0,13-0,15 MPas (1,3–1,5 kgfs/cm2) in system, providing temperature increase of the beginning of boiling of cooling liquid and preventing intensive steam formation. Unfortunately, when jamming the valve in a closed position at an overheat there is considerable excess of excessive pressure — more than 0,15 MPas (1,5 kgfs/cm2) that can lead to a rupture of a broad tank or failure of one of hoses. In turn, jamming of the valve in open situation leads to premature boiling of cooling liquid. Therefore once a year wash out a stopper of a broad tank flowing water. If there were doubts, replace a stopper. It is obvious that if on the superheated engine to remove a stopper of a broad tank and on time this action will coincide with heatstroke, then boiling up of liquid and formation of air traffic jams in the cooling system are guaranteed. Once a year blow radiator cells a stream of compressed air (for example, from the compressor), directing a stream at first towards to the running air stream, and then in its direction for removal from a surface of a radiator of dirt, the stuck insects and road garbage. It is so possible to restore efficiency of a radiator partially.