The scheme of diagnostics of malfunctions covers the most often found malfunctions and their possible reasons. At the correct diagnostics malfunction has to be eliminated with replacement of a detail, adjustment or repair, depending on need.

For reduction of loss of time by search and definition of malfunctions in the cooling system it is necessary to answer questions of car service conditions which could lead to extreme operating modes of the cooling system.

1. Whether there was an engine overheat during towage of the trailer? If affirmative answer, then what was trailer weight? If the weight of the trailer exceeds 450 kg, then use of the special cooling system is required (see. "Recommendations of the manufacturer of the trailer"). If at the same time the car had the ordinary cooling system, further diagnostics is not required.

2. Whether the car with air conditioning system after its purchase was equipped? If affirmative answer whether then the special radiator of the increased efficiency for work with the conditioner was established. If is not present, establish a special radiator (see. "Recommendations of the manufacturer"). Further diagnostics is not necessary.

3. Whether there was an engine overheat in operating time idling to the included transfer and the working conditioner? If affirmative answer – observe the technology of driving excluding an engine overheat as, for example:

– during the work idling try to install whenever possible the transmission in neutral situation, increase the frequency of rotation of a bent shaft of the engine for increase in a stream of air and cooling liquid through a radiator;

– if the index of temperature or a control lamp signal about an engine overheat during its long work idling, switch off the conditioner. Further diagnostics is not required.

4. Whether there was an engine overheat during long slow driving in city conditions, frequent traffic jams, in a garage? If affirmative answer – observe the technology of driving excluding an overheat as well as for long work idling. Further diagnostics is not required.

If any of above-mentioned conditions is not executed, pass to work with the scheme of search and definition of malfunctions.

For effective work with this scheme define what of the listed below malfunctions took place:

– the burning lamp of the indicator of an overheat or the indication of the index of temperature of cooling liquid;

– boiling of cooling liquid;

– lowering of the level of cooling liquid.

1. If as a cause of defect serves fire of a control lamp or the indication of temperature whether then it was followed by boiling up of cooling liquid? If affirmative answer, then begin "boiling" with a step if the answer "no" – begin with a step "the overheat indicator" on the scheme of search of malfunctions.

2. If a cause of defect – boiling, begin "boiling" of the scheme with a step. If malfunction is still not eliminated, pass to diagnostics of the fan of a radiator.

3. If liquid lowering of the level is a cause of defect, define whether cooling liquid at its dolivka was poured. At a modulation a small amount of cooling liquid can pour out through a drainage tube. In this case you watch the correct level at a dolivka of cooling liquid. Further diagnostics is not required. If a problem not in a modulation, you pass to a step "Lowering of the level" on the scheme.

       PREVENTION

If there is a pollution of cooling liquid, obviously, it is necessary to merge liquid and to wash out the cooling system.

The cooling system works with a high pressure and temperature of 93 °C. At removal of a stopper of a broad tank at service of system it is necessary to observe precautionary measures.

If any of the malfunctions of components specified on the scheme of search does not demand repair, it is necessary to carry out two groups of inspections in the following order.

1. Remove the big objects blocking a radiator or the condenser:

– additional coolers of transmission liquid;

– registration plates;

– spare wheels;

– ice, dirt or snow which hammered a radiator core.

2. – check too high level of oil in the engine the index of level of oil.

3. The radiator does not correspond to this car. Compare number of a radiator according to the catalog to number specified in specifications of the car.

4. Unreliable consolidation, damage or lack of sealants of a body – see. "Instruction on service of a body".

5. The lower rejecting air plate – is absent or is damaged see. "Guide to service of a body".

6. The wrong installation of a corner of an advancing of ignition – see. "Guide to service of the engine".

1. Inappropriate type of the fan or the faulty fan of a radiator – to compare number according to the catalog to number specified in specifications of the car.

2. Check the cooling system under pressure with use of a test stopper, at the same time it will be visible whether injury of a jellied mouth of a radiator is the reason of leaks.

3. Faulty water pump:

– corrosion or breakage of a krylchatka of the pump;

– malfunction of the bearing or an epiploon – check existence of a side play of a shaft or the bearing.

4. Radiator tubes are hammered – check a radiator in auto repair shop.

5. Internal leaks in the cooling system:

– laying of a head of cylinders is damaged;

– a crack in the block of cylinders;

– the casing of a gear belt is damaged;

– laying of an inlet collector is damaged.

6. Canals of cooling liquid in a head of cylinders are filled – remove a head and examine it.

If the engine overheats with boiling of cooling liquid, perform the following operations.

1. Pit pressure in the cooling system and accurately remove a radiator stopper.

2. Apply with an indicator pencil on 93 °C a tag on the thermostat case.

3. Warm up the engine at the accelerated idling rotation frequency. Watch circulation of cooling liquid through a radiator prior to thawing of an indicator tag on the thermostat case.

If circulation of liquid takes place, so a cause of defect not in the thermostat. If circulation of liquid is absent, replace the thermostat and check system again to be convinced of its serviceability.

If the cold engine slowly gets warm, perform the following operations.

1. Pit pressure in the cooling system and accurately remove a radiator stopper.

2. Apply with an indicator pencil on 93 °C a tag on the thermostat case.

3. Warm up the engine at the accelerated idling rotation frequency. Watch circulation of cooling liquid through a radiator prior to thawing of an indicator tag on the thermostat case.

If circulation of liquid takes place, so a cause of defect not in the thermostat. If circulation of liquid is absent, replace the thermostat and check system again to be convinced of its serviceability.

       NOTE

The indicator pencil is similar to a usual pencil and contains paraffin material with certain chemical additives which provide the set melting temperature. By means of drawing by a pencil on 87 °C and 93 °C it is possible to check temperature of opening of the thermostat for the case of the thermostat of tags. These tags have to thaw at achievement by cooling liquid of temperatures of 87 °C and 93 °C, respectively. These temperatures determine the range of opening of the thermostat. Therefore if circulation does not happen as it is required, so the thermostat can be faulty.