Service Infiniti QX4 since 1996 of release
1. Introduction
2. The maintenance instruction
3. Routine maintenance
4. The engine
4.1. Specifications
4.2. Check компрессионного pressure in cylinders
4.3. Diagnostics of a condition of the engine with vacuum gauge application
4.4. Removal and engine installation
4.5. Removal and installation of the inlet pipeline
4.6. Replacement of a belt of drive ГРМ
4.7. Removal, check of a condition and installation of a head of cylinders
4.8. Replacement of a forward epiploon of a cranked shaft
4.9. Removal, check of a condition and installation of components клапанного the mechanism
4.10. Replacement of epiploons of camshafts
4.11. Replacement of a back epiploon of a cranked shaft
4.12. Removal and pallet installation картера
4.13. Removal, service and installation of the oil pump
4.14. Alternative variants of schemes of regenerative repair of the engine
4.15. An order of dismantling of the engine by its preparation for major repairs
4.16. Dismantling and check of a condition of a head of cylinders and components клапанного the mechanism
4.17. Recommendations about service of valves
4.18. Assemblage of a head of cylinders
4.19. Removal of shatunno-piston assemblages
4.20. Removal of a cranked shaft
4.21. Cleaning of the block of the engine
4.22. Check of a condition of the block of the engine
4.23. Хонингование mirrors of cylinders
4.24. Check of a condition of components of shatunno-piston group
4.25. Check of a condition of a cranked shaft
4.26. Check of a condition and selection of loose leaves radical and шатунных bearings of a cranked shaft
4.27. An engine assembly order
4.28. Installation of piston rings
4.29. Installation of a cranked shaft and check of working backlashes of radical bearings
4.30. Installation of shatunno-piston assemblages and check of size of working backlashes in шатунных bearings of a cranked shaft
4.31. Trial start and обкатка the engine after major repairs
5. Cooling and heating systems
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


4.24. Check of a condition of components of shatunno-piston group

Preliminary shatunno-piston assemblages should be carefully cleared. Rings are necessary for removing from pistons.

Piston rings are subject to replacement without fail.


  1. By means of the special adaptation remove rings from pistons, — try not to damage a wall of the last casually.
  2. Scratch out from the bottoms of pistons traces of coal adjournment. After removal of the basic layer of adjournment smooth out a surface manually a wire brush or a piece of a fine-grained emery paper.

At all do not use for зачистки made of a soft material and pistons easily subject to erosion wire nozzles to an electrodrill!

  1. By means of the special adaptation clean flutes under installation of rings on pistons.

It is alternatively possible to take advantage for this purpose of a fragment of an old piston ring, however be careful, — do not scratch a bottom and walls of a flute and do not cut fingers.

  1. Having removed the basic adjournment, wash out шатунные assemblages by solvent and carefully dry them, whenever possible with application of compressed air. Check up passableness масловозвратных apertures in back walls of flutes under installation of piston rings, and also oil apertures in the bottom heads of rods.

At using the compressed air do not forget to put on goggles!

  1. If walls of pistons and a mirror of cylinders are not damaged and excessively are not worn out, and the engine block was not pierced and not replaced, necessity for replacement of pistons also disappears. Normal deterioration of pistons is shown in the form of vertical traces of development on a persistent surface and a small weak point of landing top компрессионного rings in the flute. Do not forget that replacement of piston rings is made without fail, without dependence from their condition.
  2. Attentively examine each of pistons on presence of cracks in a skirt, round ledges under installation of piston fingers and around an arrangement of rings.
  3. Check up persistent surfaces of a skirt of the piston on presence of scratches, the bottom — on presence of through apertures and прогаров on edge. Presence of scratches on a skirt can be regarded as a sign of long overheats of the engine, or too early ignition of an air-fuel mix, — check up serviceability of functioning of system of cooling. Прогары along the edges of the bottom are the detonation certificate. In any case, the reason of the revealed infringement should be eliminated in order to avoid relapses. As the possible reasons of formation of the listed defects leaks of soaked up air, wrong configuration of an air-fuel mix, infringement of installation of a corner of an advancing of ignition, wrong functioning of systems of ignition and EGR can act also.
  4. Dot corrosion of pistons in the form of cavities speaks about hit in chambers of combustion and-or картер the engine of a cooling liquid. Besides, take care, that the reason of internal leaks has been eliminated.

  1. Estimate size of a lateral backlash of landing of piston rings in the flutes for what enclose a new ring outside in the flute on the piston and щупом лезвийного type measure a remaining backlash. Repeat measurement in two-three points on flute perimetre. Watch to mixing компрессионные a ring (the top differs from the second). If the backlash size exceeds admissible value (Specifications see), pistons are subject to replacement.

  1. Define a landing backlash of pistons in the cylinders for what measure diameters of the last (see Check of a condition of the block of the engine) and subtract from them diameters of corresponding pistons. Measurement of diameter of the piston is made on a persistent surface at an angle 90 to an axis of a piston finger and on the set removal from a skirt cut.

On engines considered in the present Management selective landing of pistons in cylinders is provided. Thus cylinders and pistons in appropriate way are marked.

A — the Site of marks of dimensional groups of cylinders
B — At installation шатунных assemblages pistons should appear are developed by forward labels on the bottoms forward on the engine


  1. If the landing backlash of the piston in the cylinder exceeds admissible value (Specifications see), it is necessary to give the block in проточку with a selection of new pistons of repair diameter.
  2. Estimate correctness of landing of pistons on rods, having tried повращать components in opposite directions. Presence a little appreciable люфта speaks about excessive deterioration of a joint.

  1. Mark pistons on conformity to the cylinders, — numbers of cylinders фабрично are put on rods and covers шатунных bearings.

  1. Remove a lock ring of fixing of the piston on a rod.

  1. Warm up pistons in an oil bath to temperature 60—70С, then squeeze out of the top heads of rods piston fingers.

Alternatively pistons can be removed at a room temperature with application of a special press.

  1. Check up rods on presence of signs of deformations. Compare results of measurements to requirements of Specifications, in case of need make replacement.

    A — rod Check on a bend
    B — rod Check on twisting


  1. For the purpose of definition of landing backlashes measure diameter of a piston finger and apertures under its landing in the top head of a rod and in the piston.

    A — Measurement of diameter of a piston finger and an aperture under its landing in the top head of a rod
    B — Measurement of diameter of an aperture in the piston under landing of a piston finger


  1. Compare results of corresponding calculations to requirements of the Specifications, excessively worn out components replace, — at squeezing from a rod of the top plug use approaching the mandrel, at landing track correctness of combination of oil apertures.
  1. At assemblage the new lock ring is established on the piston by the equipped facet the party (if the facet in general is provided) from the piston. Having planted a ring warm up the piston in an oil bath, plant on a rod (track correctness of orientation of components on labels) and запрессуйте a finger (the rod should appear precisely in the middle).
  1. Plant the second lock ring (also new) and check up freedom of rotation of the piston on a finger.
  1. At installation of piston assemblages track, that pistons have been developed by forward labels on the bottoms forward on the engine. Do not forget that number marks on covers шатунных bearings and the bottom heads of rods should settle down on the one hand assemblages.
  1. In regular intervals tighten bolts of covers of bearings with demanded effort and check up size axial люфта rods on pins of a cranked shaft. Compare results of measurements to demanded effort, in case of need replace corresponding rods and-or a cranked shaft.

On page back
4.23. Хонингование mirrors of cylinders
On the following page
4.25. Check of a condition of a cranked shaft