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


4.2. Check компрессионного pressure in cylinders

Results of check компрессионного pressure in cylinders allow to define the general condition of components of the top part of the engine (pistons, piston rings, valves, linings of a head of cylinders, etc.) and qualitatively to estimate degree of their deterioration. That is especially important, the analysis of the information received as a result of check allows to narrow a spectrum of the possible reasons of falling of a compression in cylinders, precisely enough having adhered refusal to infringements of functioning of quite concrete components, whether it be piston rings, valves, their saddles or a head lining.

The engine should be heated-up to normal working temperature, and the storage battery is completely charged.


  1. Begin with procleaning of candle niches (blow their compressed air as which source in this case the ordinary bicycle pump perfectly will approach). The Primary goal is prevention of hit of dust in cylinders during performance of measurements.
  2. Turn out from the engine all spark plugs (Routine maintenance see the Head).
  3. Fix throttle заслонку in completely open position.
  1. For pressure dump in the power supply system switch off ignition and take from the landing nest in салонном the assembly block a safety lock of the fuel pump, then start the engine and wait its spontaneous останова, — for dump of residual pressure turn the engine of 2-3 more times a starter, then switch off ignition and establish into place a safety lock.
  1. Disconnect central ВВ a wire from a cover of the distributor of ignition.
  1. Establish компрессометр in a candle aperture of the first cylinder.
  1. At use of a nozzle of clamping type track, that diameter of a rubber cone made no more than 20 mm.
  1. Turn the engine at least on seven steps and consider the measuring instrument indication. On the serviceable engine pressure should accrue quickly enough. Low pressure upon the first step, accompanied by its gradual increase on the subsequent, speaks about deterioration of piston rings. If at further проворачивании a shaft pressure does not rise, it can be regarded as the certificate of leaks of valves or infringement of tightness of a lining of a head of cylinders (the probability of presence of cracks in a head is not excluded also). The congestion of adjournment on working facets of plates of valves also can lead to decrease компрессионного pressure. Write down the maximum indication компрессометра.
  2. Repeat procedure for the remained cylinders of the engine. Compare results to standard requirements (Specifications see).
  3. At excessively low results of measurement, fill in in each of cylinders through a candle aperture a little impellent oil (two-three teaspoons) and repeat check.

If oil addition leads to pressure increase, it speaks about deterioration of piston rings. If the compression does not increase, the reason of its decrease are leaks of valves or infringement of tightness of a lining of a head. Leaks of valves can be connected with a burn-out of their saddles, either deformation / by a burn-out or mechanical damages of working facets of plates.

If pressure of compression is equally underestimated in two next cylinders with high degree of probability it is possible to speak about infringement of integrity of a lining of a head within its crosspiece between the given cylinders. Presence of a cooling liquid at impellent oil will confirm the given assumption.

If pressure in one of cylinders approximately on 20 % more low, than in other and it is accompanied by infringement of stability of turns of idling, it is necessary to estimate degree of deterioration of a cam of a drive of the corresponding final valve on a camshaft.

Unusual overestimate компрессионного usually is a consequence of pressure excessive нагарообразования in combustion chambers. In this case the head of cylinders should be removed for the purpose of carrying out декарбонизации.

At excessively low results of measurements, and also in case of infringement of uniformity of distribution of pressure between cylinders it will be useful to hold testing of the engine for leaks in the conditions of a car-care centre workshop. Such check will allow to define precisely a source of leak and to estimate degree of its gravity.

Block check on leaks

During the given check are defined speed of an exit from cylinders закачанного in them of the compressed air and it is direct places of leaks. The given check is alternative to compression check. Moreover, from many points of view, it is much more effective as visually to reveal a source of leak easier, than to comprehend results of measurement of a compression.

The equipment necessary for check on leaks, is not among popular, therefore performance of the given check should be entrusted experts of the service centre.

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4.1. Specifications
On the following page
4.3. Diagnostics of a condition of the engine with vacuum gauge application