Service of the Infiniti QX4 since 1996 of release
1. Introduction
2. Maintenance instruction
3. Routine maintenance
4. Engine
4.1. Specifications
4.2. Check of compression pressure in cylinders
4.3. Diagnostics of a condition of the engine with use of the vacuum gage
4.4. Removal and installation of the engine
4.5. Removal and installation of the inlet pipeline
4.6. Replacement of a belt of the GRM drive
4.7. Removal, check of a state and installation of a head of cylinders
4.8. Replacement of a forward epiploon of a bent shaft
4.9. Removal, check of a state and installation of components of the valvate mechanism
4.10. Replacement of epiploons of camshafts
4.11. Replacement of a back epiploon of a bent 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 recovery repair of the engine
4.15. An order of dismantling of the engine by preparation it to capital repairs
4.16. Dismantling and check of a condition of a head of cylinders and components of the valvate mechanism
4.17. Recommendations about service of valves
4.18. Assembly of a head of cylinders
4.19. Removal of conrod and piston assemblies
4.20. Removal of a bent 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 conrod and piston group
4.25. Check of a condition of a bent shaft
4.26. Check of a state and selection of inserts of radical and conrod bearings of a bent shaft
4.27. Engine assembly order
4.28. Installation of piston rings
4.29. Installation of a bent shaft and check of working gaps of radical bearings
4.30. Installation of conrod and piston assemblies and check of size of working gaps in conrod bearings of a bent shaft
4.31. Trial start and a running in of the engine after capital repairs
5. Cooling system and heating
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
 












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 valvate 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 can always be ordered in a workshop of car service or in a warehouse branded HUNDRED Infinitis. In view of need of use during dismantling and check of a condition of a head of some special tools, authors of this manual consider, than to be got involved what to the amateur mechanic more simply and cheaper will be to get a replaceable head in rather complex recovery repair of worn-out.

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

 PERFORMANCE ORDER

  1. By means of the special tool squeeze 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 valvate springs it is convenient to use nippers or a small magnet.
  1. Put the removed components of valvate assemblies 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 a maslootrazhatelny cap from the directing plug. If there is a jamming of the valve in the directing plug, push it back in a head and an oselok or a file with small tooth accurately smooth out edges of a flute under installation of crackers.
  1. Working in a similar manner, remove the remained valvate assemblies. Put the removed components of each of valves in the separate, equipped with the corresponding label package — at assembly each detail has to be established strictly on the former place.
  2. After all components of the valvate mechanism are taken and put in an organized order, it is possible to start performing procedures of cleaning and check of a condition of a head (at full-scale recovery repair of the engine before finish its dismantling).


Cleaning

Careful cleaning of a head of cylinders and components of the valvate mechanism with the subsequent detailed check of their state will help to determine the approximate volume of the forthcoming recovery work.

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 all traces of material of old laying and sealant from the interfaced surfaces of a head of cylinders, the inlet pipeline and a final collector — try not to damage surfaces. Application of a special razmyagchitel which should impregnate previously stuck deposits will significantly facilitate work.
  2. Remove all traces of a scum from walls of water channels.
  3. Rigid wire brush carefully clean all available cavities and openings. At strong pollution of canals the clearing of a head should be charged to experts.
  4. "Banish" the tap suitable by the size each of bolted openings, having removed corrosion products, traces of old sealant from a carving and having restored the damaged rounds. In the presence of access to a source of compressed air, blow openings, having removed from them shaving and small garbage.

When using 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 compressed air will allow to reduce significantly the term of drying and will give a quality assurance of a clearing of badly available cavities and openings.

Different structures for removal of traces of a deposit significantly facilitating implementation of the procedure of cleaning can be got in many shops of automobile accessories. Remember that such means usually are chemically aggressive and have to be applied with observance of the appropriate measures of precaution — strictly adhere to instructions of the manufacturers who are usually given on the label of a container.

  1. Wash out solvent of a yoke of the drive of valves, then carefully dry them. Use of compressed air will significantly facilitate implementation of the procedure (do not forget to put on goggles). Wash out in solvent and carefully dry valvate springs, their plates and crackers of cutting locks. Try not to mix components.
  2. Scratch out the bulk of the valves of deposits created on surfaces, then a wire nozzle to the electric drill finally smooth out surfaces of cores and plates of valves — you watch that valves were not mixed.


Check of a state and service of components


Casting of a head

 PERFORMANCE ORDER

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

The pro-point is allowed only in case height of a head does not go beyond the lower admissible bound (see Specifications).


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


Valvate springs

A.

B.

Valvate the free length, perpendicularity of a tortsovka and the developed effort are among the parameters which are subject to check (see Specifications).

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


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


Maslootrazhatelny caps — an installation order

 PERFORMANCE ORDER

  1. Establish a saddle of an internal spring, oil a new cap pure motive and by means of a suitable mandrel accurately put him on the directing valve plug.

    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.


The directing plugs — replacement

 PERFORMANCE ORDER

  1. Heat a head of cylinders to temperature of 150 — 160 °C. The head should be warmed in an oil bathtub.
  1. Then by means of a press or the hammer and a drift squeeze out / beat out the directing plugs of valves which are subject to replacement from a head of cylinders in I will shift combustion chambers. Having finished dismantle of plugs, let's a head cool down to room temperature.
  1. By boring achieve reduction of internal diameters of landing nests of the 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 a head to temperature of 150 — 160 °C and press new guides of the plug in a head on the required depth — basic parameter is the size of a vystupaniye of plugs over surfaces of saddles of external valvate 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 valvate saddles has to be made after performing procedures of service of the 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 a head of cylinders up to the temperature of 150 — 160 °C and press repair saddles in reception nests — track completeness of landing of saddles. By a countersink and grinding achieve reduction of width and size of a corner of working facets of saddles in compliance with standard requirements:

Tilt angle of a facet (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 conclusion make grinding in of valves with use of special abrasive pastes of various granularity.


Valves


The geometrical parameters of valves which are subject to measurement

D — Diameter of a plate
a — the Tilt angle of a working facet
The t is Width of a cylindrical part of a plate (corbel)

d — Diameter of a core
L — Full length


 PERFORMANCE ORDER

  1. Make check of the under control sizes of valves (see an illustration the geometrical parameters of valves which are 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 the size of a side play of speakers 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 the directing plugs.
  1. The size of a landing gap can be determined by measurement of diameters of cores of valves and internal diameters of the corresponding guides of plugs, or by landing of the valve in the plug and direct measurement by means of the dial measuring instrument of plunger type. Compare results of check to requirements of Specifications, in case of need make replacement of valves / guides of 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 the 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 the 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 for existence of deep scratches, zadir 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 outer diameter of an axis of yokes (the nominal rate makes: 17.979 — 18.000 oo)
    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 oo)

A.

B.


Hydraulic pushers

 PERFORMANCE ORDER

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

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

A.

B.
  1. Having established pushers, check serviceability of their state in free situation (without emphasis in a yoke). For check firmly press a pusher a finger (the size of a landing gap: 0.043 — 0.066 oo). If movement size when pressing exceeds 1 mm, means in a pusher air got — removal of air happens automatically about 10 minutes of operation of the engine later without loading on turns of 1000 in a minute. If after pumping the noise background published by the valvate mechanism does not decrease, pushers should be replaced (pumping of new pushers is made in a similar manner).


"on the page back
4.15. An order of dismantling of the engine by preparation it to capital repairs
on the following page"
4.17. Recommendations about service of valves