Service of the Infiniti QX4 since 1996 of release
1. Introduction
2. Maintenance instruction
3. Routine maintenance
3.1. Schedule of routine maintenance
3.2. Specifications
3.3. General information about settings and adjustments
3.4. Check of levels of liquids
3.5. Check of a condition of tires and pressure of their rating, rotation of wheels
3.6. Replacement of motive oil and oil filter
3.7. Check of a state and replacement of the hoses located in a motive compartment
3.8. Service of the cooling system (depletion, washing and filling)
3.9. Check, service and charging of the rechargeable battery
3.10. Check of a state and belts of the drive of auxiliary units
3.11. Replacement of spark plugs, check of a condition of VV of an electrical wiring
3.12. Replacement of the filtering air cleaner element
3.13. Check of a state and replacement of brushes of screen wipers, a clearing and adjustment snuffled supply of the washing liquid
3.14. Survey of components of a suspension bracket and steering drive, check of a condition of protective covers of power shafts
3.15. Check of the brake system
3.16. Check / adjustment of installations of turns of an idling / corner of an advancing of ignition / quality of air-fuel mix
3.17. Check of electric equipment
3.18. Check of serviceability of functioning and service of systems of heating and air conditioning
3.19. Greasing of locks, loops and emphasis
4. Engine
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


3.11. Replacement of spark plugs, check of a condition of VV of an electrical wiring

The spark plug consists of the central electrode, the insulator with the case and a weight electrode(s). Between the central electrode and an electrode of weight the spark igniting air-fuel mix slips. It is not necessary to apply the spark plugs other than recommended. The recommended type of candles is defined among other things by kalilny number.

The Kalilny number characterizes degree of thermal loading of a candle. The kalilny number of a candle is lower, the degree of its thermal loading is higher. At the same time the candle takes away heat better thanks to what the possibility of kalilny ignition of fuel mix is excluded. The candle with the high thermal characteristic has that shortcoming that its temperature of self-cleaning lies above. It is more inclined to formation of a deposit, in particular when the engine in operating time often does not reach the working temperature, for example the movement in the city, short movements by winter.

The correct kalilny number of a candle is defined by the manufacturer of the car. There are candles with one or several electrodes of weight, with various length of a carving and its diameter. When replacing a candle it is necessary to establish only the candles corresponding to instructions of the manufacturer of the car.

Middle service life of a candle is various. At the same time a serious role is played also by material of electrodes. Chrome-nickel alloy is characterized by very high heat conductivity and resistance to impact of corrosion. Silver whereas platinum electrodes differ in high anticorrosive properties and firmness against an obgoraniye has the best heat-removing properties. Service life of candles makes from 20 000 to 100 000 km of a run, depending on material of electrodes and their quantity.

Depending on a design of the engine of a candle distinguish as consolidation of landing in a head of cylinders.

At flat landing the sealing ring which is usually fixed on the case of a candle is used and is not subject to removal. Candles of conical landing in application of additional sealing elements do not need and differ in more compact sizes.

Service life of spark plugs with the central electrode covered with a platinum layer is much higher than at candles of other types.

Efficiency of return of the engine considerably is defined by correctness of functioning of spark plugs. It is important that candles of the corresponding type were installed on the engine (on the Infiniti QX4 models candles with platinum electrodes regularly are established).

Need for unplanned service of spark plugs arises extremely seldom provided that actually the engine is in good repair. In order to avoid casual damage of electrodes, it is not necessary to make cleaning of candles without use of the special equipment.

In most cases replacement of spark plugs requires existence of a special candle head (with an elastic insert inside) complete with the ratchet drive, and also set for a safe detachment of tips of VV of wires from shafts of spark plugs the special tool is also issued though its application and is not strictly obligatory. Use of a dynamometer key will allow to achieve the correct effort of tightening of candles.

Before turning out candles their adjusting niches it is necessary to blow compressed air for the purpose of prevention of hit of garbage in cylinders — it is the simplest to use the ordinary bicycle pump).

Check of a condition of candles gives a good idea of a condition of the engine. If on the insulator of the central electrode completely there are no traces of any deposits, it says about reimpoverishment of air-fuel mix, or that excessively "hot" candle is used (heat removal to the case on "hot" candles comes from the insulator much less intensively, than on "cold").

Presence on electrodes of a black deposit demonstrates mix reenrichment and if the deposit at the same time still has an oily consistence, it is necessary to think also of more detailed assessment of degree of wear of internal components of the engine.

The raid of a golden or gray-brown shade on the insulator confirms serviceability of a condition of the engine and correctness of configuration of air-fuel mix.

Verify the turned-out candle with the card of states that will allow to estimate the general condition of the engine qualitatively.

Card of conditions of spark plugs

Typical damages of spark plugs

Coal deposits

Symptoms: Availability of soot indicates reenrichment of fuel-air mix or weak intensity of a spark. Causes admissions of ignition, complicates start and results in instability of operation of the engine.
Recommendations: Check whether the air cleaner is hammered, whether fuel level in the float-operated camera is not too high, whether the air gate is jammed and whether contacts are not too worn-out. Try to use candles with longer insulator that increases the resilience to pollution.


Symptoms: Oiling of a candle is caused by wear of maslootrazhatelny caps. Oil gets to the combustion chamber through worn-out guides of valves or piston rings. Causes admissions of ignition, complicates start and results in instability of operation of the engine.
Recommendations: Make mechanical restore


Symptoms: Porous, white insulator, erosion of electrodes and lack of any deposits. Leads to reduction of service life of a candle.
Recommendations: Check whether the kalilny number of the established candles conforms to requirements of Specifications, whether the ignition advancing corner is correctly exposed, whether too poor fuel-air mix moves, whether there is no leak of vacuum of the inlet pipeline and whether valves are jammed. Check also the level of a cooler and whether the radiator is corked.

Too early ignition

Symptoms: Electrodes are melted off. The insulator has white color, but maybe is polluted owing to admissions of ignition or hit in combustion chambers of foreign particles. Can lead to an engine exit out of operation.
Recommendations: Check kalilny number of the established candles, an ignition advancing corner, quality of mix (whether it is not too grown poor) whether the cooling system is corked and whether the lubrication system normally functions.

Electroconductive luster

Symptoms: The insulator has yellowish color and the polished appearance. Speaks about sudden temperature increase in combustion chambers at sharp acceleration. Usual deposits at the same time are melted off, taking a form of a varnish covering. Leads to admissions of ignition at high speeds of the movement.
Recommendations: Replace candles (colder, at preservation of a manner of driving).

Short circuit of electrodes

Symptoms: Waste of products of combustion gets to interelectrode space. Firm deposits accumulate, forming a crossing point between electrodes. Leads to refusal of ignition in the cylinder.
Recommendations: Remove deposits from interelectrode space.

Normal state of a candle

Symptoms: Gray-brown color and easy wear of electrodes. The Kalilny number of candles corresponds to type of the engine and its general state.
Recommendations: When replacing candles establish candles of the same type.


Symptoms: Soft deposits of brownish color on one or both electrodes of a candle. A source of their education are the applied additives to oil and/or fuel. Excessive accumulation can lead to isolation of electrodes and cause admissions of ignition and unstable operation of the engine at acceleration.
Recommendations: At bystry accumulation of deposits change maslootrazhatelny caps that will prevent hit of oil in combustion chambers. Try to replace fuel brand.


Symptoms: A rounding off of electrodes with a small congestion of deposits on the working end. Color is normal. Leads to difficulty of start of the engine in cold damp weather and to increase in fuel consumption.
Recommendations: Change candles on new, the same type.


Symptoms: Insulators can be chopped off or burst. Also inaccurate technology of adjustment of a candle gap can lead to damage of the insulator. Can lead to damage of pistons.


Symptoms: After admissions of ignition during a long period of adjournment can be loosened at preservation of working temperature in the combustion chamber. At high speeds of adjournment in flakes come off the piston and stick to the hot isolation center, causing admissions of ignition.
Recommendations: Replace candles or smooth out and establish into place old.

Mechanical damages

Symptoms: Can be caused by hit of foreign materials in the combustion chamber or arise at blow of the piston about too long candle. Lead to refusal of functioning of the cylinder and to damage of the piston.
Recommendations: Remove foreign particles from the engine and/or replace.

In candles with one side electrode to the forefront there is a factor of correctness of installation of an interelectrode gap by which size intensity of sparking and, as a result, correctness of ignition of mix and development of process of its combustion in all modes of operation of the engine is defined. Installation of interelectrode gaps has to be made according to instructions of manufacturers of candles.

Authors of the present manual are solidary with manufacturers Infiniti and do not recommend to make attempts of restoration of regularly established candles with platinum electrodes by cleaning of the last and correction of an interelectrode gap.

Measurement of size of an interelectrode gap on candles of adjustable type is performed by means of the special probe of wire type.

At adjustment it is necessary to turn in only a side electrode — attempts of deformation of the central electrode are fraught with irreversible damage of the insulator. The nozzle for updating of the provision of an electrode usually is included in the probe package.

If the probe of lezviyny type is used to measurement of a candle gap usual, the gap can be considered adjusted correctly when the edge(s) of the probe is passed in it with an easy resistance.


  1. Before installation of a candle make sure that the carving tip (shaft) is densely screwed, and a carving on the case and an external surface of a candle are well cleaned.
  1. Manually acquire one of new candles in the corresponding opening in the engine. Having made sure that the candle is not warped in a carving, tighten it with the required effort (in the presence of near at hand dynamometer key). For simplification of the procedure of a nazhivleniye of a candle pull a piece of a flexible fuel hose on its shaft — at the same time the probability of failure of a carving as at the slightest zakusyvaniye the hose will begin to be turned simply is excluded. Working in a similar manner, establish all remained candles.
  1. Before connecting to the wire VV spark plugs, perform procedures of service of the last (see below).
  2. Connection to a candle of VV of a wire is carried out by rotary progress of its tip — the last has to sit down densely on a candle shaft (pay attention to marking of wires).

Check of a condition of candle wires

Check of a condition of VV of an electrical wiring should be made regardless of that, replacement of spark plugs was made, or not.


  1. Check begins with external survey of isolation of wires at the working engine. Drive the car into the dark room, start the engine and make sure of lack of sparking on wires. Sparking is an isolation breakdown sign. Try not to touch moving components in a motive compartment. Make necessary marks on replacement of defective wires, then let's the engine cool down.
  2. Check of candle wires is made serially in order to avoid violation of an order of their connection at assembly. Usually on isolation of company wires there is the corresponding marking. In case of absence that, put it independently by means of an adhesive tape and a marker.
  1. Disconnect VV a wire from a spark plug (best of all use the special tool). Do not pull for a wire, only for its tip at all.
  1. Attentively examine internal walls of a tip. Corrosion is usually shown in the form of a fragile korkoobrazny raid of white color.
  2. Pull a tip back on a shaft of the candle, make sure of density of its landing. In case of need again remove a tip and turn in plugs in a rubber cover.
  3. Wipe with pure rags a wire on all its length, having completely removed traces of dirt and lubricant from the surface of isolation. Examine isolation of a wire on existence of cracks, traces of a progar and other damages. Try not to bend a wire under acute angles in order to avoid violation of integrity of veins of the conductor in isolation.
  4. Check a condition of contacts of wires from the ignition distributor — again pull only for a tip.

Replacement of VV of an electrical wiring should be made a set, even in case of failure of only one of wires.

Even at an excellent condition of system of ignition, at for start-up during wet weather there can be failures — in case of need spray system elements the moisture absorbing spray — ask in shops of automobile accessories.

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3.10. Check of a state and belts of the drive of auxiliary units
on the following page"
3.12. Replacement of the filtering air cleaner element