Nissan Maxima QX

since 1993 of release

Repair and car operation

Nissan Maxima QX
+ Nissan Maxima brand Cars
+ Maintenance instruction
+ Settings and routine maintenance
+ Engine
- Systems of cooling, heating
   General information
   Antifreeze - general information
   Check of serviceability of functioning and thermostat replacement
   Check of a condition of fans of system of cooling and chains of their inclusion, replacement of components
   Removal and installation of a radiator and expanded tank of system of cooling
   Check of a condition and replacement of the water pump
   Check of serviceability of functioning and replacement of the block of the sensor of a measuring instrument of temperature of cooling liquid
   Check of serviceability of functioning of the driving electromotor of the fan of a heater and condition of components of its electric chain, …
   Removal and installation of the electromotor of a drive of the fan of a heater
   Removal and installation of assembly of the control panel by functioning of a heater and air conditioner, adjustment of a driving cable
   Removal and installation of the heat exchanger of a heater
   Check of serviceability of functioning and service of systems of heating and air conditioning
   Removal and receiver dehumidifier installation To/in
   Removal, service and To/in compressor installation
   Removal and To/in condenser installation
+ Power supply system and release
+ engine Electric equipment
+ Control systems of the engine
+ Transmission
+ Coupling and power shafts
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment

General information

Arrangement of components of systems of cooling, heating and air conditioning in an impellent compartment of the car

1 — the Radiator
2 — the Condenser
3 — the Fan of system of cooling
4 — the Water pump

5 — the Thermostat
6 — the Broad tank
7 — the Accumulator/dehumidifier

Thermostat components

1 — the Flange
2 — the Piston
3 — the pumping Valve
4 — the Main screw spring

5 — a valve Saddle
6 — the Main valve
7 — the Frame
8 — the Secondary screw spring

The scheme of circulation of cooling liquid with DOHC engines


The scheme of circulation of cooling liquid with SOHC engines


Schematic diagram of central air of air


Function chart of central air of air


System of cooling of the engine

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. 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.

Heating system

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.

Air central air

Functional and basic schemes of central air of air it is presented on accompanying illustrations.

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 (accumulator) 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. The coolant pumped over through the heat exchanger begins to boil and, evaporating, selects at air surplus of heat. The temperature in salon thus decreases to demanded comfortable value (at the choice of the operator). The compressor supports coolant circulation in system, pumping over the warmed-up liquid via the condenser where it is cooled and arrives back in the evaporator.

 Cars considered in the real Management are equipped with system of additional safety of SRS which is better known as a safety cushion. Before performing any works near assembly of a pillow or a steering column, without fail disconnect system in order to avoid receiving traumas as a result of its casual operation, - disconnect from the battery at first negative, then for a positive wire and wait not less than two minutes before starting service of the components located near sensors of directed overloads (see. Head Onboard electric equipment). Isolation and contact sockets of electroconducting of a chain of SRS are painted in bright yellow color. It is not necessary to connect any diagnostic devices to this chain!