Service of the Infiniti QX4 since 1996 of release
1. Introduction
2. Maintenance instruction
3. Routine maintenance
4. Engine
5. Cooling system and heating
5.1. Specifications
5.2. Antifreeze - general information
5.3. Service of the cooling system
5.4. Removal, installation and check of serviceability of functioning of the thermostat
5.5. Removal, recovery repair and installation of a radiator of the cooling system
5.6. Replacement of the water pump
5.7. Removal and installation of the fan of the cooling system
5.8. Air ducts of distribution of the air given to salon
5.9. System of automatic air conditioning – a design and the principle of functioning
5.10. Structure of the refrigerator highway of the air conditioning system
5.11. The K/V compressor, - the general information and the principle of functioning
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 the air conditioning system
6. Feed and control systems
7. Systems of start and charge
8. Transmission line
9. Brake system
10. Suspension bracket and steering
11. Body
12. Electric equipment


5.13. Check of serviceability of functioning and service of systems of heating and air conditioning

Information given below has the general character and is not tied to concrete design of components of system.

Air conditioning system

The air conditioning system constantly is under high pressure. Do not disconnect refrigerator lines at all and do not remove any components of system, previously without having executed a discharge of the last. The discharge of the air conditioning system has to be made by forces of the skilled expert in the conditions of a workshop of car service. At a rassoyedineniye of refrigerator lines surely put on goggles!

The listed below control checks have to be made on a regular basis for the purpose of maintenance of the air conditioning system in good repair:

  • Check a condition of a belt of the drive of the compressor. In case of detection of defects or signs of wear make replacement (see the Head Routine maintenance);
  • Check effort of a tension of a driving belt, in case of need make the corresponding adjustment (see the Head Routine maintenance);
  • Check hoses of a refrigerator path for existence of cracks, swellings, signs of hardening and aging of rubber, estimate a condition of nipple connections. Replace defective components;
  • Check condenser heat exchanger plates for existence of the remains of insects, old leaves and other garbage which got stuck between them. In case of need clean gaps a thin brush, or blow them compressed air;
  • Check system charge level (see below);
  • At detection of potek of water on rugs in salon under the dashboard pick up the drainage phone of removal of condensate from a casing of the evaporator and a piece of a wire check passability of both openings.

The air conditioning system has to turn on at least for 10 minutes at least once a month (even in winter season). Long inaction To/in leads to hardening and failure of sealing rings and cuffs of a connecting path.

The leaks taking place in a path in the best way are shown at increase in working parameters of system (temperature and pressure) — leave the conditioner included for 5 — 10 minutes at the working engine. Sources of leaks can be revealed on oil poteka.

In view of complexity of a design of system and need of use of the special equipment, its service, deep diagnostics and recovery repair lie outside qualification of the average amateur mechanic and have to be made in the conditions of a workshop of car service. Only the elementary checks and replacements which are listed below in the present section get to competence of the owner of the car.

If the system does not function at all, check a condition of the corresponding safety lock and the relay.

To/in decrease in level of a charge of refrigerator oil is the most typical cause of infringement of serviceability of functioning. The elementary checks given below will allow to reveal signs of decrease in level of coolant quickly.

Check of level of a charge of coolant


  1. Warm up the engine up to the normal working temperature.
  2. Include To/in on the maximum refrigerating capacity. Choose the maximum high-speed mode of the fan. Open doors to avoid cyclic shutdowns of system when cooling of the air volume closed in salon.
  3. Operation of a clutch coupling of the K/V compressor is followed by distinctly heard click after which the central part of the coupling has to begin to rotate. After temperature of system will reach working value, feel two tubes connected to the evaporator on a partition of a motive compartment.
  1. Thinner tube going to the evaporator from the output union of the condenser has to be to the touch rather cold. The tube is thicker, going from the final union of the evaporator back to the compressor, has to be a little more (by 2 — 6 degrees) more cold. If the final tube is to the touch much warmer inlet, therefore, the system needs recharge. Enter the thermometer into an output air duct via the central deflector on the dashboard. At included To/in temperature of the air which is going out of the deflector has to be 2 — 4.5 degrees lower than ambient temperature (up to value of 4.5 °C). In very hot weather (it is above +40 °C), increase in output temperature to the level of 15.7 °C, but is admissible no more. If the conditioner does not provide the required intensity of cooling of air, it is necessary to make recharge of system. For more detailed diagnostics of a condition of system the car should be driven away in a specialized workshop.
  1. Glance in the observation port which is usually provided in a cover of assembly of a receiver dehumidifier — foaming of coolant in a receiver demonstrates falling of its level. In hot weather bubbles at an observation port can be present even at the normal level of working liquid — after shutdown of system foaming has to stop.

Coolant addition

For charging of the air conditioning system of the cars considered in the present manual it is necessary to use only refrigerator R-134a oil.


  1. Prepare the standard charging R-134a set (ask in shops of automobile accessories). The valve nozzle and the piece of a hose connected between the gate and the union of a low pressure part of the refrigerator highway are a part of set a barrel with refrigerator oil. As one barrel of oil it can appear insufficiently for final charging of system, it makes sense to buy just in case at once couple. Track that at least in one of barrels oil was tinted in red color that will allow to reveal quickly leak of coolant in case of those.

Do not fill more than two barrels of coolant in system at all!

  1. According to instructions of manufacturers connect charging set to the LOW PRESSURE part of the refrigerator highway.

Do not make attempts of connection of set to the union of a high-pressure part of the highway at all! The design of nipple connections allows to make connection of set only to a low pressure part of system.

  1. Close the gate on a transitional nozzle and screw the last on a barrel head, previously having made sure available a sealing ring / rubber laying.

Surely put on goggles!

  1. Remove a dustproof cap from the union of a low pressure part of the refrigerator highway and connect to it the hose of charging set equipped with the socket of bystry joining.

The design of nipple knots will not allow to make connection of set to a high-pressure part of the highway.

  1. Warm up the engine up to the normal working temperature and include К/В. Track that the hose of charging set did not adjoin to blades of the fan of the cooling system and other moving components in a motive compartment.
  2. Rotation of a valve nozzle pierce a barrel head, having opened thereby coolant supply (the characteristic sound of the escaping gas has to be heard). In the course of all charging you discipline a barrel vertically, from time to time stirring up it. Charging should be interrupted when temperatures of inlet and final tubes of the evaporator are compared. Between series of charging do the pause necessary for stabilization of system.

Do not download more than two barrels of coolant in system at all! In order to avoid frosting of a barrel in the course of gas station wrap up its towel moistened in warm water.

  1. In the presence of near at hand exact thermometer enter it in via the deflector into the central air duct To/in and you watch on it temperature of the air given to salon (see above).
  2. When the barrel becomes empty, block the gate and disconnect a hose from the low pressure union of system. At once put on a dustproof cap the union.
  3. Disconnect a valve nozzle from a barrel, in case of need rearrange it on the second barrel and continue gas station. At the end of the procedure put an unfinished barrel vertically on a rack and as required use it for recharge of system.

System of heating

If the heater does not provide due heating of the air given to salon, one of the following can be the reason of such refusal:

  • The thermostat is jammed in open situation that does not allow the cooling liquid of the engine given to the heat exchanger of a heater to heat up to normal temperature. Replace the thermostat (see Service of the cooling system);
  • Violation of passability of a cooling path takes place that blocks supply of cooling liquid in the heater heat exchanger. Feel the hoses connected to branch pipes on a back partition of a motive compartment — both of them have to be hot, otherwise passability of a path is broken (hoses, the heat exchanger, or the operating heater gate are blocked). Disconnect hoses and make obratnopotochny washing of the heat exchanger. Wash out also both hoses;
  • If it is not possible to restore passability of the heat exchanger by washing, it is necessary to make its replacement.

If the speed of rotation of the fan of a heater does not correspond to the chosen position of the corresponding switch on the system control panel, check a condition of a safety lock, a connecting electrical wiring, the relay, switch and resistive assembly.

If the air outlet via deflectors is absent at all, take the following actions:

  • Include ignition and activate the heater fan. Press an ear to the deflector and try to define aurally whether the driving motor functions;
  • If the sounds confirming serviceability of functioning of the motor are absent, and resistive assembly as it should be, it is necessary to replace an electric motor.

Moistening of a carpet on a floor under the heater heat exchanger, or a steam-out via deflectors of air ducts is told about leakages of the heat exchanger. Remove the heat exchanger and replace it new (the heater heat exchanger is not subject to recovery repair).

Check passability of the drainage hose going from assembly of the heater/evaporator and laid the spravy party of a partition. Blocking of this hose can lead to a steam-out from deflectors of air ducts at inclusion of a heater.

Elimination of smells of the air conditioning system

The unpleasant smells often arising at inclusion To/in are caused by formation of colonies of a mold on evaporator heat exchanger plates. The warm damp environment creates favorable conditions for emergence and development of fungal microorganisms.

Access to the evaporator heat exchanger on the majority of models is extremely limited. The procedure of the guaranteed full removal of a mold which is carried out in the conditions of a workshop of car service is rather labor-consuming, takes away a lot of time and demands use of strong disinfectants. In principle, rather effective processing can be executed also in house conditions by own forces of the owner of the car.

The special disinfectants in aerosol packaging intended for service of air conditioning systems can be bought practically in any shop of automobile accessories. It is necessary to remember that the price of means is usually directly proportional to its efficiency. Switch system to the mode of the closed air circulation and for ten minutes turn on the heater fan on the maximum speed. For the purpose of drying of system include heating on the maximum intensity. Disconnect an electrical wiring from the compressor for the purpose of prevention of its operation.

Giving of means is usually carried out through a long hose according to instructions of his manufacturer. Try to process all surface of the heat exchanger most fully. Duration of each operation cycle and intervals between series have to be specified on the label of a container.

The best preventive measure against emergence of colonies of a mold in the heat exchanger of the evaporator is regular check of passability of a drainage tube, and also short-term inclusion of the mode of removal of condensate after each distant trip with the working conditioner for the purpose of drying of the evaporator.

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5.12. A receiver dehumidifier - the general information and service
on the following page"
5.14. Diagnostics of the air conditioning system