Nissan Maxima QX

since 1993 release

Repair and operation of the car



Nissan Maxima QX
+ Cars of the Nissan Maxima brand
+ Maintenance instruction
+ Settings and routine maintenance
- Engine
   + SOHC engines
   - DOHC engines
      General information
      Preparatory actions and the list of repair procedures which can be executed without extraction of the engine from the car
      Reduction of the piston of the first cylinder in the provision of the top dead point (TDP)
      Removal and installation of covers of heads of cylinders
      Check and adjustment of gaps of valves
      Replacement of maslootrazhatelny caps and valvate springs with plates
      Removal, check of a state and installation of a chain and asterisks of the GRM drive
      Removal and installation of camshafts and pushers of valves
      Removal and installation of the inlet pipeline
      Removal and installation of final collectors
      Removal and installation of heads of cylinders
      Removal and installation of a pulley of a bent shaft
      Replacement of a forward epiploon of a bent shaft
      Removal and installation of the pallet of a case of the engine
      Removal, check of a state and installation of the oil pump
      Removal and installation of a flywheel / driving disk
      Replacement of a back epiploon of a bent shaft
      Check of a state and replacement of support of a suspension bracket of the power unit
   + General capital repairs of the engine
+ Cooling systems, heating
+ 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



Replacement of maslootrazhatelny caps and valvate springs with plates

Replacement of the broken valvate springs and worn-out maslootrazhatelny caps can be made without dismantle of heads of cylinders. Only two special adaptations and a source of compressed air will be necessary. Before starting performance of work, make sure available near at hand rather powerful tool for tightening of the hard valvate springs used for a complete set of engines of the considered models of cars.


 PERFORMANCE ORDER

1. Remove the top section of the inlet pipeline (see the Section Removal and installation of the inlet pipeline) both a cover (and) head(s) of cylinders (see the Section Removal and installation of covers of heads of cylinders).
2. Remove a GRM drive chain (see the Section Removal, check of a state and installation of a chain and asterisks of the GRM drive). Take camshafts and pushers of valves (see the Section Removal and installation of camshafts and pushers of valves).
3. Turn out spark plugs from cylinders which components need check. If there is a need for replacement of maslootrazhatelny caps, turn out all candles.
4. Having turned a bent shaft, bring the corresponding piston into the provision of VMT of the end of a step of compression (see the Section Reduction of the Piston of the First Cylinder in the provision of the top dead point (TDP)). When replacing maslootrazhatelny caps, begin with the first cylinder, then you pass from one to another as ignition (see Specifications).
5. Screw a long transitional nozzle in a candle opening of the corresponding cylinder and connect to it a hose from a source of compressed air.

In view of the fact that the directing tubes of candles have rather big length, the special transitional nozzle for connection of a source of compressed air will be required. Special nozzles with the socket of bystry connection are issued, - ask in shops of automobile accessories.

6. Give air to the cylinder.

Under pressure of air the piston can move down that it will lead to a sudden provorachivaniye of a bent shaft - do not leave on the bolt screwed in a shaft pin, a face key by means of which brought the piston into the provision of VMT. Valves will be kept on the place by air pressure.

7. In order to avoid hit in the engine of garbage and other foreign objects, a zakuporta rags all openings in the block around the valves which are subject to service. Now by means of the special tool squeeze a spring of the served valve. By means of tweezers or the magnetized core take from flutes on a valve core crackers of the cutting lock.

If it is not possible to fix the valve in a closed position compressed air, therefore, the tightness violation determined by existence of mechanical defects of a working facet of a plate of the valve or its saddle takes place. In that case the head of cylinders needs to be removed from the engine for the purpose of performance of the corresponding recovery repair.

8. Remove from a valve core a plate springs and actually a spring, then remove a maslootrazhatelny cap from the directing plug.
9. Fix a rubber bandage on the top end of a core of the valve, or reel up an adhesive tape to exclude a possibility of falling of the valve in the combustion chamber, then block air supply in the cylinder.
10. Check a valve core for existence of signs of wear or mechanical damages. Rotating the valve in the directing plug, estimate the size of a radial side play of its end face defining degree of straightness of a core (the curved valve is subject to replacement).
11. Move the valve up-down in the directing plug, trying to reveal jamming points which existence demonstrates or deformation of a core of the valve, or about damage of the plug - anyway the head is subject to removal for the purpose of performance of necessary recovery repair.
12. Again give air to the cylinder for the purpose of fixing of the valve. Remove a rubber bandage / adhesive tape from a core.

13. Oil a valve core pure motive and establish a new maslootrazhatelny cap.

Special mandrels for landing of caps to plugs are issued, however, in this case also the deep face head of the corresponding size perfectly will approach. Zastukivaniye of a cap is made by the hammer through a mandrel.

14. Put on a valve core a valvate spring (an end face with the shortened step of rounds to a head).
15. Put a plate on a spring, then squeeze a spring by means of the special tool and accurately fill in a landing flute on a valve core crackers of the cutting lock. For temporary fixing of crackers to an otpuskaniye of the tool grease them with dense lubricant from within.
16. Watching correctness of landing of crackers in a flute, release the device for tightening of a spring.
17. Block air supply in the cylinder and turn out a transitional nozzle from a candle opening.
18. Install into place camshafts and pushers of valves (see the Section Removal and installation of camshafts and pushers of valves). Establish a GRM drive chain (see the Section Removal, check of a state and installation of a chain and asterisks of the GRM drive).
19. Establish a cover of a head of cylinders (see the Section Removal and installation of covers of heads of cylinders).
20. Screw to the place of a spark plug, coils and the top section of the inlet pipeline (see appropriate sections of this Part of the present Chapter).
21. Start the engine and check it for existence of signs of leak of oil and the unusual noise published by the valvate mechanism.