Service Infiniti QX4 since 1996 of release
1. Introduction
2. The maintenance instruction
3. Routine maintenance
4. The engine
5. Cooling and heating systems
5.1. Specifications
5.2. Antifreeze - the general data
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 an automatic air conditioning – a design and a functioning principle
5.10. A design of a refrigerator path of a central air of air
5.11. Compressor K/V, - the general information and a functioning principle
5.12. The Receiver-dehumidifier - the general information and service
5.13. Check of serviceability of functioning and service of systems of heating and an air conditioning
5.14. Diagnostics of a central air of air
6. Power supply systems and managements
7. Start and charge systems
8. A transmissionnaja line
9. Brake system
10. A suspension bracket and a steering
11. A body
12. An electric equipment


5. Cooling and heating systems

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

The scheme of functioning of system of cooling

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

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

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

Доливание a cooling liquid in system it is made through a mouth of a broad tank which simultaneously acts also in a role of the receiver accumulating in superseded from radiator surplus of a liquid.

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

System of an automatic air conditioning

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

At reception of commands from the control panel of system of the climate control the automatic amplifier analyzes the data developed by information gauges and by means of delivery of corresponding signals on actuation mechanisms provides formation of the requested environmental conditions in car salon.

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

Performance of any regenerative repair of a central air should be entrusted to experts of car-care centre.

Air giving in salon is made through air lines of obverse and foot levels. The choice of a direction of distribution and physical parametres of an air stream is carried out by means of the switch of the control panel of system (the Maintenance instruction see the Head). Air expense 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 be cooled, depending on a choice of a temperature mode of a heater / of system of the climate control (see more low). There is a possibility of activation of a mode of the closed air circulation. The detailed description of principles of management is resulted by functioning of systems of ventilation / of heating / of air-conditioning in the Head the Maintenance instruction.

Principle of the organisation of heating of air

The basic 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 by means of rubber hoses is connected to system of cooling of the engine. The block of management is built in by functioning of a heater / of the conditioner of air in the panel of devices of the car. Разогретая in the engine the cooling liquid circulates through the heater heat exchanger, giving the to air warmly filling a casing. At inclusion of heating of salon there is an opening lamellar заслонки therefore the internal volume of a casing of a heater incorporates to salon volume. At fan inclusion крыльчатка air submitted to salon through the heat exchanger starts to banish the last, providing its intensive warming up.

Principle of the organisation of functioning of a central air of air

The system structure includes the condenser established ahead of a radiator close to the heat exchanger of a heater the evaporator, fixed on the block of the engine the compressor and a receiver-dehumidifier equipped редукционным with the 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 (for choice the operator).

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

Safety measures at service of components of system K/V

Central air service 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 gathering and order of storage of an automobile coolant.

  • Do not suppose coolant hit on open sites of a skin;
  • At performance of procedures of service of components of system K/V without fail put on goggles;
  • At coolant hit on a skin or in eyes do not pound the amazed 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 50С. 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 spent in well aired premise. Evaporation of a flying coolant in 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 than air and rather quickly accumulates in the bottom volumes of a premise, in particular, under the car;
  • At coolant combustion poisonous gas is formed;
  • Store a coolant far from open sources of fire. Do not smoke. At using plasma течеискателем avoid smoke inhalation;
  • At carrying out of welding works near to system K/V components try not to suppose a warming up of the last, — the overheat can lead to pressure increase in system and to ignition;
  • Do not make cleaning of the condenser or the evaporator with steam application, — use only cold or compressed air.

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4.31. Trial start and обкатка the engine after major repairs
On the following page
5.1. Specifications