Infiniti QX4 service since 1996 of release
1. Introduction
2. Maintenance instruction
3. Routine maintenance
4. Engine
4.1. Specifications
4.2. Check of kompressionny pressure in cylinders
4.3. Diagnostics of a condition of the engine with use of the vacuum gage
4.4. Removal and engine installation
4.5. Removal and installation of the inlet pipeline
4.6. Replacement of a belt of a drive of GRM
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 of the klapanny mechanism
4.10. Replacement of epiploons of camshafts
4.11. Replacement of a back epiploon of a cranked shaft
4.12. Removal and installation of the pallet of a case
4.13. Removal, service and installation of the oil pump
4.14. Alternative versions of schemes of regenerative repair of the engine
4.15. An order of dismantling of the engine by its preparation for major maintenance
4.16. Dismantling and check of a condition of a head of cylinders and components of the klapanny mechanism
4.17. Recommendations about service of valves
4.18. Assembly of a head of cylinders
4.19. Removal of shatunno-piston assemblies
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. Honingovaniye of 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 of radical and shatunny bearings of a cranked shaft
4.27. Engine assembly order
4.28. Installation of piston rings
4.29. Installation of a cranked shaft and check of working gaps of radical bearings
4.30. Installation of shatunno-piston assemblies and check of size of working gaps in shatunny bearings of a cranked shaft
4.31. Trial start and an engine running in after major maintenance
5. Cooling and heating systems
6. Power supply systems and managements
7. Start and charge systems
8. Transmission line
9. Brake system
10. Suspension bracket and steering
11. Body
12. Electric equipment
 












4-16-razborka-i-proverka-sostoyaniya-golovki-cilindrov-i-komponentov-klapannogo-mekhanizma.html

4.16. Dismantling and check of a condition of a head of cylinders and components of the klapanny mechanism


Design of a head of cylinders

 

During dismantle of components try to fix their adjusting provisions.


Dismantling of a head of cylinders

The new or restored head of cylinders always can be ordered in a workshop of car-care center or in a warehouse firm HUNDRED Infinitis. In view of need of use during dismantling and check of a condition of a head of some special tools, originators of this Management consider that to the amateur mechanic more simply and will cheaper get a replaceable head, than to be got involved in rather difficult regenerative repair of the worn-out.

Dismantling of a head of cylinders demands preliminary dismantle of the klapanny mechanism (inlet and final valves with accompanying components). It is meant that yokes with axes and camshafts are already taken from a head (see. Removal, check of a condition and installation of components of the klapanny mechanism).

 PERFORMANCE ORDER

  1. By means of the special tool compress springs of the first valve and take from a flute on a core crackers of the cutting lock of a plate. Carefully release the tool and remove from the valve a plate of springs, springs and their saddle (depending on a complete set). For extraction of crackers of the cutting lock after compression of klapanny springs it is convenient to use nippers or a small magnet.
  1. The removed components of klapanny assemblies put in accurately numbered separate plastic bags (an inscription on a label: components of the inlet valve of the third cylinder).
  1. Further, take the valve from a head of cylinders and remove from the directing plug a maslootrazhatelny cap. If there is a valve jamming in the directing plug, push it back in a head and an oselok or a file with small tooth accurately smooth out flute edges under installation of crackers.
  1. Operating in a similar manner, remove the remained klapanny assemblies. Put removed components of each of valves in the separate package equipped with the corresponding label — at assembly each detail should be established strictly on the former place.
  2. After all components of the klapanny mechanism will be taken and combined in the organized order, it is possible to start performance of procedures of cleaning and check of a condition of a head (at full-scale regenerative repair of the engine before finish its dismantling).


Cleaning

Careful cleaning of a head of cylinders and components of the klapanny mechanism with the subsequent detailed check of their condition will help to define approximate volume of the forthcoming recovery operations.

Strong overheats of the engine can lead to deformation of a head of cylinders and violation of planeness of its interfaced surfaces (see below).


 PERFORMANCE ORDER

  1. Scratch out from interfaced surfaces of a head of cylinders, the inlet pipeline and a final collector all traces of a material of old laying and hermetic — try not to damage surfaces. Will essentially facilitate work application of a special razmyagchitel to which should impregnate the stuck deposits previously.
  2. Remove from walls of water channels all traces of a scum.
  3. Rigid wire brush carefully clean all available cavities and openings. At strong pollution of channels it is necessary to charge pro-cleaning of a head to experts.
  4. "Banish" a tap suitable on the size each of boltovy openings, having removed from a carving corrosion products, traces of old hermetic and having restored the damaged rounds. In the presence of access to a source of the compressed air, blow openings, having removed from them shaving and small garbage.

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

  1. Wire brush smooth out a carving of hairpins of fastening of the inlet pipeline and a final collector.
  2. Wash out a head solvent and carefully dry it. Use of the compressed air will allow to reduce essentially term of drying and will give a quality assurance of pro-cleaning of badly available cavities and openings.

For removal of traces of the deposit, procedures of cleaning essentially facilitating performance, it is possible to get different structures in many shops of automobile accessories. Remember that such means usually are chemically aggressive and should be applied with observance of the appropriate measures of precaution — strictly adhere to instructions of the manufacturers who have been usually brought on a label of container.

  1. Wash out solvent of a yoke of a drive of valves, then carefully dry them. Use of the compressed air will essentially facilitate procedure performance (do not forget to put on goggles). Wash out in solvent and carefully dry klapanny springs, their plates and crackers of cutting locks. Try not to mix components.
  2. Scratch out bulk of the valves of deposits created on surfaces, then a wire nozzle to an electrodrill finally smooth out surfaces of cores and plates of valves — watch, that valves did not appear are mixed.


Check of a condition and service of components


Head molding

 PERFORMANCE ORDER

  1. Having used the tool for compression of klapanny springs (J-39773), remove components of klapanny assemblies.
  1. By means of a steel ruler and щупа lezviyny type estimate size of not planeness of an interfaced surface of a head — in case of need give molding to a pro-point.

The pro-point is allowed only in case the height of a head does not fall outside the limits the bottom admissible border (see. Specifications).


The total thickness of the ground-off layer of interfaced surfaces of a head and the block should not exceed 0.20 mm!


Klapannye of a spring

A.

B.

The free length, perpendicularity of a tortsovka and developed effort belong to number of parameters subject to check klapanny (see. Specifications).

A — Check of a tortsovka of a klapanny spring (the limiting admissible size S makes: 2.2 mm for external springs and 1.9 mm for internal)
B — Check of effort developed by a klapanny spring by means of a dinamometrichesky press


External klapanny springs are established by the party with the reduced step of a carving to a head.


Maslootrazhatelnye caps — an installation order

 PERFORMANCE ORDER

  1. Establish a saddle of an internal spring, grease a new cap with pure impellent oil and by means of a suitable opravka accurately plant it on directing plug of the valve.

    A — Landing of a maslootrazhatelny cap to the directing plug
    B — the Scheme of landing of a maslootrazhatelny cap on the directing plug

A.

B.


Directing plugs — replacement

 PERFORMANCE ORDER

  1. Heat up a head of cylinders to temperature 150 — 160°С. The head should be warmed up in an oil bath.
  1. Then by means of a press or a hammer and a drift squeeze out / beat out directing plugs of valves subject to replacement from a head of cylinders in I will shift combustion chambers. Having finished dismantle of plugs, let's to a head cool down to room temperature.
  1. By boring achieve reduction of internal diameters of landing nests of directing plugs in compliance with standard requirements. The repair sizes make: 11.175 — 11.196 mm for plugs of inlet valves and 12.175 — 12.196 mm for final.
  1. Again heat up a head to temperature 150 — 160°С and press new directing plugs in a head on demanded depth — basic parameter is the size of a vystupaniye of plugs over surfaces of saddles of external klapanny springs (the nominal rate makes 13.2 — 13.4 mm).
  1. By boring achieve reduction of internal diameters of plugs in compliance with standard requirements (the repair sizes make: 7.000 — 7.018 mm for plugs of inlet valves and 8.000 — 8.011 for final) — track compliance to norms of landing gaps in plugs of cores of valves (see the subsection "Valves").


Saddles of valves — replacement


Under control parameters of saddles of inlet valves


Under control parameters of saddles of final valves

Replacement of klapanny saddles should be made after performance of procedures of service of directing plugs.

Extraction of saddles is made by their protachivaniye before destruction, track, that the cutter did not pass a head wall through.

 PERFORMANCE ORDER

  1. Take saddles and chisel landing nests under the repair size (the repair size with excess 0.5: 44.500 — 44.516 for saddles of inlet valves and 37.500 — 37.516 mm for final — under control geometrical parameters of saddles of valves — see illustrations Under control parameters of saddles of inlet valves and Under control parameters of saddles of final valves).
  2. Warm up a head of cylinders to temperature 150 — 160°С and press repair saddles in reception nests — track completeness of landing of saddles. By a countersink and polishing achieve reduction of width and size of a corner of working facets of saddles in compliance with standard requirements:

Tilt angle facets (alpha), degrees:

  • Saddles of inlet and final valves

45

Width of a facet, mm

  • Saddles of inlet valves

1.75

  • Saddles of final valves

1.70

  1. In summary make grinding in of valves with application of special abrasive pastes of various granularity.


Valves


Geometrical parameters of valves subject to measurement

D — Diameter of a plate
a — the Tilt angle of a working facet
T — Width of a cylindrical part plates (corbel)

d — Diameter of a core
L — Full length


 PERFORMANCE ORDER

  1. Make check of the under control sizes of valves (see an illustration geometrical parameters of valves Subject to measurement). Compare results of measurement to requirements of Specifications. In case of need make replacement.

Performance of a pro-point of cores of valves, but no more than 0.2 mm is in case of need allowed.

  1. Measure size люфта acting on 30 mm from plugs of valves in the plane perpendicular to camshafts — if the result of measurement exceeds 0.20 mm, check landing gaps of valves in directing plugs.
  1. The size of a landing gap can be defined by a way of measurement of diameters of cores of valves and internal diameters of the corresponding directing plugs, or by valve landing in the plug and direct measurement by means of a tsiferblatny measuring instrument of plunzherny type. Compare results of check to requirements of Specifications, in case of need make replacement of valves / directing plugs.

    A — Measurement of size of a gap of landing of the valve in the directing plug
    B — Calculation of size of a gap of landing of the valve in the directing plug

A.

B.
  1. At installation track size of a vystupaniye of cores of valves.

    A — the Scheme of installation of the inlet valve
    B — the Scheme of installation of the final valve

A.

B.


Components of a drive of valves


Assemblies of axes of yokes

 PERFORMANCE ORDER

  1. Remove assembly of an axis of yokes.
  1. Mark adjusting provisions of yokes on an axis. Check components on existence of deep scratches, задиров and signs of excessive wear.
  1. Remove yokes and check gaps of landing of yokes on axes. In case of need make the corresponding replacements.

    A — Measurement of external diameter of an axis of yokes (the nominal rate makes: 17.979 — 18.000 mm)
    B — Measurement of diameter of a landing opening of a yoke (the nominal rate makes: 18.007 — 18.028 mm, size of a landing gap: 0.007 — 0.049 mm)

A.

B.


Hydraulic pushers

 PERFORMANCE ORDER

  1. Check landing nests of pushers in a head of cylinders on existence of deep scratches, задиров and signs of excessive wear.
 
  1. Measure external diameters of pushers and internal diameters of their landing nests and by subtraction of results of the first measurement from results of the second define size of landing gaps. Compare results of calculations to requirements of Specifications, in case of need make replacement of components.

    A — Measurement of external diameter of a pusher (shooters showed the surfaces which condition should be checked); the nominal rate makes: 15.947 — 15.957 mm
    B — Measurement of diameter of a nest under pusher landing

A.

B.
  1. Having established pushers, check serviceability of their condition in free situation (without an emphasis in a yoke). For check firmly press a pusher a finger (size of a landing gap: 0.043 — 0.066 mm). If the moving size by pressing exceeds 1 mm, means in a pusher air got — removal of air occurs automatically about 10 minutes of operation of the engine later without loading on turns 1000 in a minute. If after pumping the noise background published by the klapanny mechanism does not decrease, it is necessary to replace pushers (pumping of new pushers is made in a similar manner).


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4.15. An order of dismantling of the engine by its preparation for major maintenance
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4.17. Recommendations about service of valves