Infiniti QX4 service since 1996 of release
1. Introduction
2. Maintenance instruction
3. Routine maintenance
4. Engine
5. Cooling and heating systems
5.1. Specifications
5.2. Antifreeze - general information
5.3. Service of system of cooling
5.4. Removal, installation and check of serviceability of functioning of the thermostat
5.5. Removal, regenerative repair and installation of a radiator of system of cooling
5.6. Replacement of the water pump
5.7. Removal and installation of the fan of system of cooling
5.8. Air lines of distribution of air submitted to salon
5.9. System of automatic air conditioning – a design and a functioning principle
5.10. Design of a refrigerator path of central air of air
5.11. The To/in compressor, - the general information and a functioning principle
5.12. A receiver dehumidifier - the general information and service
5.13. Check of serviceability of functioning and service of systems of heating and air conditioning
5.14. Diagnostics of central air of air
6. Power supply systems and managements
7. Start and charge systems
8. Transmission line
9. Brake system
10. Suspension bracket and steering
11. Body
12. Electric equipment



5. Cooling and heating systems

All models of cars considered in the real Management are equipped with system of cooling of the engine working at superfluous pressure with thermostatic management of circulation of working liquid.

Scheme of functioning of system of cooling

The water pump of rotor type is fixed on the block of the engine and provides pumping of cooling liquid through an okhladitelny path of the last. The stream of liquid washes regions of an arrangement of each of cylinders in the block and goes to a back part of the engine. Laid in molding of the block and a head of cylinders okhladitelny channels provide intensive cooling of inlet and final ports, areas of installation of spark plugs and directing plugs of final valves.

The Voskozapolnenny thermostat supervises working temperature of the engine in the course of its warming up. The first minutes after start of the cold engine the thermostat remains closed, preventing thereby circulation of cooling liquid through a radiator. When the temperature of the engine reaches normal working value, the valve of the thermostat opens, connecting to a cooling contour a radiator providing the maximum intensity of a heat-conducting path from a working body (cooling liquid).

The system of cooling has a tight design and is densely closed by a cover of the radiator, capable to maintain a certain superfluous pressure that provides increase of a boiling point of cooling liquid and, respectively, efficiency of a heat-conducting path through a radiator. At excess by internal pressure in system of some certain value, the podpruzhinenny plate of the radiator of a safety valve built in in a cover rises over the saddle, providing an overflowing of excess of cooling liquid on a connecting (perelivny) tube in a broad tank. In process of system cooling liquid automatically comes back from a tank to a radiator.

Dolivaniye of cooling liquid in system is made through a mouth of a broad tank which at the same time acts also as a receiver accumulating in forced out from a radiator excess of liquid.

In view of the listed features of a design, such system of cooling received the name closed as in it any functional losses of cooling liquid are excluded.

System of automatic air conditioning

The system of automatic air conditioning (climate control) is included into a standard complete set of the Infiniti QX4 models. Information sensors, the management block enter into a contour of management of system / the automatic amplifier and a set of actuation mechanisms.

When receiving teams from the control panel of system of climate control the automatic amplifier analyzes the data developed by information sensors and means of delivery of the corresponding signals on actuation mechanisms provides formation of the requested climatic conditions in car salon.

The automatic amplifier carries out also function of the block of self-diagnostics of refusals of К/В system.

Performance of any regenerative repair of central air should be entrusted to specialists of car-care center.

Supply of air in salon is made through air lines of obverse and foot levels. The choice of the direction of distribution and physical parameters of an air stream is carried out by means of the switch of the control panel of system (see. Head Maintenance instruction). The consumption of air is regulated by a choice of a high-speed mode of functioning of the fan of a heater. At will of the operator air submitted to salon can be warmed up or cooled, depending on a choice of a temperature mode of heater / system of climate control (see below). There is a possibility of activation of a mode of the closed air circulation. The detailed description of principles of management is provided by functioning of systems of ventilation / heating / conditioning in Head the Maintenance instruction.

Principle of the organization of heating of air

The main components of system of heating of salon are the electric fan and the heat exchanger located in a box-shaped casing of a heater. The heat exchanger is connected by means of rubber hoses to system of cooling of the engine. The control unit is built in by functioning of the heater / conditioner of air in the car dashboard. The cooling liquid warmed up in the engine circulates via the heater heat exchanger, giving the to air warmly filling a casing. At inclusion of heating of salon there is an opening of a lamellar zaslonka therefore the internal volume of a casing of a heater incorporates to salon volume. At turning on of the fan the krylchatka of the last starts to banish air submitted to salon via the heat exchanger, providing its intensive warming up.

Principle of the organization of functioning of central air of air

The structure of system includes the condenser established ahead of a radiator close to the heat exchanger of a heater the evaporator, fixed on the engine block the compressor and a receiver dehumidifier equipped with the reduktsionny valve of a high pressure. All components are connected among themselves by refrigerator lines.

The fan banishes air arriving in salon through the heat exchanger of the evaporator working in a mode, the return to a mode of functioning of a radiator. A coolant pumped over through the heat exchanger, evaporating, selects at air surplus of heat. The temperature in salon thus decreases to demanded comfortable value (at the choice of the operator).

The electronic control system carries out control of functioning of systems of heating and conditioning, providing maintenance possibility in salon set temperatures (climate control).

Precautionary measures at service of components of To/in system

Service of central air should be made by exclusively prepared technicians trained in receptions of safe performance of procedures, having skills of work with the special equipment, with observance of rules of a discharge of the system, acquainted with receptions of collecting and order of storage of an automobile coolant.

  • Do not allow coolant hit on open sites of skin;
  • At performance of procedures of service of components of To/in system without fail put on goggles;
  • At coolant hit on skin or in eyes do not pound the struck place — immediately wash out cold water within not less than 15 minutes and at once address to the doctor. Do not try to self-medicate at all;
  • The coolant is in a new cylinder under pressure. Store a cylinder at temperature not above 50°С. Take the measures excluding risk of falling of a cylinder from height or creation of other situations which can lead to its damage;
  • Works should be carried out in well aired room. Evaporation of a flying coolant in the atmosphere leads to decrease in level of concentration of oxygen that can be at the bottom of difficulty of breath;
  • Remember that in a gaseous state the coolant is heavier some air and rather quickly accumulates in the bottom volumes of a room, in particular, under the car;
  • At combustion of a coolant poisonous gas is formed;
  • Store a coolant far from open sources of fire. Do not smoke. When using a plasma techeiskatel avoid smoke inhalation;
  • At carrying out welding works near components of To/in system try not to allow a warming up of the last — the overheat can lead to pressure increase in system and to ignition;
  • Do not make condenser or evaporator cleaning with steam application — use only cold or the compressed air.

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5.1. Specifications