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
   + SOHC Engines
   + DOHC Engines
   - General major maintenance of the engine
      General information
      Check of pressure of oil
      Check of kompressionny pressure in cylinders
      Diagnostics of a condition of the engine with use of the vacuum gage
      Alternative versions of schemes of regenerative repair of the engine
      Removal of the power unit from the car - preparation and precautionary measures
      Removal and engine installation
      Order of dismantling of the engine by its preparation for major maintenance
      Dismantling of a head of cylinders
      Cleaning and check of a condition of a head of cylinders
      Service of valves
      Assembly of a head of cylinders
      Removal of shatunno-piston assemblies
      Removal of a cranked shaft
      Cleaning of the block of the engine
      Check of a condition of the block
      Honingovaniye of mirrors of cylinders
      Check of a condition of components of shatunno-piston group
      Check of a condition of a cranked shaft
      Check of a condition and selection of loose leaves of radical and shatunny bearings of a cranked shaft
      Check of a condition of camshafts, pushers of valves and bearings
      Engine assembly order
      Installation of piston rings
      Installation of a cranked shaft and check of working gaps of radical bearings
      Installation of a back epiploon of a cranked shaft
      Installation of shatunno-piston assemblies and check of size of working gaps in shatunny bearings of a cranked shaft
      Trial start and engine running in after major maintenance
+ Systems of cooling, 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
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Cleaning and check of a condition of a head of cylinders

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.

CLEANING

 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 previously the stuck deposits, - ask in shops of automobile accessories.
2. Remove from walls of water channels all traces of a scum.
3. A 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!

5. By means of solvent and a brass wire brush clear combustion chambers of a deposit.
6. 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.

7. On SOHC engines wash out solvent of assembly of yokes with axes. Carefully dry components with application of the compressed air and combine them in the organized order. Wash out solvent and dry pushers of valves.

Use of the compressed air will essentially facilitate procedure performance (do not forget to put on goggles).

8. Wash out in solvent and carefully dry klapanny springs, their plates and crackers of cutting locks. Try not to mix components.
9. 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.

Condition check

Before making the decision on need of carrying out machining of a head of cylinders, carefully study its condition. Having familiarized with the material stated in the real subsection, make the list of components needing special attention.

Head of cylinders

 PERFORMANCE ORDER

1. Attentively check a head of cylinders on existence of traces of leakages of cooling liquid, cracks and other damages. The burst head is subject to replacement without fail. In case of absence of confidence of definition of a condition of a head, it is necessary to send it for check in a car-care center workshop. If repair is not obviously possible, replace a defective head.

2. By means of a measuring instrument of planeness and щупа lezviyny type check an interfaced surface of a head on existence of signs of deformation. If not planeness exceeds admissible value according to standards (see.), a head it is necessary to send specifications in a pro-point in a mechanical workshop.

One and з working parameters of heads of cylinders is their minimum admissible height which should not be belittled in the course of machining.

3. Check a condition of saddles of valves in each of combustion chambers. In case of identification of cavities, cracks, traces прогара, it is necessary to subject a head to the special regenerative repair which performance lies outside the limits of qualification of the average amateur mechanic and it should be entrusted to specialists of car-care center.

4. By means of a special nutromer measure internal diameter of the directing plug of the valve. After measuring instrument extraction from the plug measurement by its micrometer is made. Measure also external diameter of a core of the valve. For the purpose of determination of size of a gap of landing of the valve in the plug subtract from result of the first measurement result of the second. Compare the obtained data with requirements of Specifications. Worn-out plugs are subject to replacement.

when using a nutromer enter it to the middle of length of the plug, then move up-down. Unevenness of resistance to moving of a measuring instrument testifies to existence of a konusnost of the plug. In the absence of confidence at definition of a condition of components do not hesitate to address for the help to experts.

Valves

 PERFORMANCE ORDER

1. Attentively check working surfaces of valves on existence of signs of non-uniform wear, deformations, cracks, cavities and traces прогара. Estimate extent of operation of cores of valves. Check, whether there are no cracks in necks of cores. By rotation check valves on a bend. Make sure of lack of cavities and signs of excessive wear of end faces. Identification of any of the listed defects demands delivery of valves for regenerative repair in a car-care center workshop.


1 — End faces (shafts) of cores
2 — Flutes under installation of crackers of cutting locks of plates
3 — Cores
4 — Working facets
5 — the Final valve
6 — the Cylindrical part plates (corbel)
7 — the Inlet valve

2. Measure width of a cylindrical part (corbel) of a plate of each of valves. If the width of a corbel appears less than the value stipulated in Specifications, replace the valve.

Components of valves

 PERFORMANCE ORDER

1. Estimate degree of wear of face parts of each of klapanny springs, check springs on existence of cavities. Measure free length of klapanny springs, compare results of measurements to requirements of Specifications. If the spring appears more shortly than the bottom admissible limit, it is given and is subject to replacement. Check also on compliance to standard requirements efforts developed by springs (performance of this work better to charge to experts of a workshop of car-care center). In the absence of confidence of definition of a condition of springs it will be more correct than them to replace.

2. Establishing each of springs vertically on a flat surface, check severity of their tortsovka. Springs with tortsovka violation, as well as given (see above), are subject to replacement.

3. Check plates of springs and crackers of their cutting locks on existence of cracks and wear signs. It is necessary to replace all details which were in a doubtful condition new in order to avoid development of defects in the future.

Camshafts, pushers of valves and assembly of yokes with axes

 PERFORMANCE ORDER

1. The description of procedures of check of a condition of the listed components is provided in the Section Check of a condition of camshafts, pushers of valves and bearings. The assessment of a condition of bearing necks of camshafts should be made before the head will be sent a workshop for carrying out service of valves. Existence on necks of scratches, задиров and other mechanical defects a head is subject to replacement regardless of a condition of components of the klapanny mechanism. At service of the SOHC engine it is necessary to check also a condition of yokes of a drive of valves with axes.
2. Replace all revealed defective components.
3. At considerable degree of wear of components of valves that is quite probable for the engine needing major maintenance, collect klapanny assemblies, establish them on the regular places in a head (see. The section Assembly of a head of cylinders) also pass to performance of procedures of service of valves (see. Section Service of valves).