1-6-diagnostika-neispravnostejj-uzlov-i-sistem-avtomobilya.html

1.6. Diagnostics of malfunctions of knots and systems of the car

The owners of cars performing procedures of routine maintenance of the vehicle it agrees the schedule provided in the Head Routine maintenance will be extremely seldom forced to address materials of this section. Reliability of the knots and components installed on modern cars is so high that at timely performance of replacement of the materials of details which are worn out and failed as a result of aging the probability of their sudden refusal is extremely small. Refusals seldom happen spontaneously and usually are a consequence sometimes of long development of defect. In particular, failure of mechanical components practically is always preceded by emergence and development of the characteristic symptoms which are shown sometimes for many thousands of kilometers of a run to the full. The same components which can fail unexpectedly usually are not vital for functioning of the main knots and systems of the car, or are easily replaced in road conditions.

Fundamental step at identification of the reasons of any refusal is the choice of a point of the beginning of searches. Often the reason is lying on a surface, however in certain cases it is necessary to work, making small investigation. The motorist who produced half-dozens of casual checks of replacements and corrections quite has chance to find a cause of failure (or its symptom), however it is impossible to call such approach reasonable, in view of its labor input and aimlessness of expenses of time and means in any way. There is a quiet logical approach to search of the failed knot or component much more effectively. Surely it is necessary to take into account everything preceding breakage, sometimes insignificant, symptoms and the guarding signals, such as loss of the power developed by the engine, change of indications of measuring instruments, emergence of unusual sounds and smells, etc. Do not forget that failure of such components as safety locks or spark plugs can be only a symptom more deeply of the hidden violation.

In this subsection rather simple scheme of diagnostics of the most often found refusals is given below. The reasons of violations and their symptoms are grouped in a sign of the relation to functioning of any concrete unit or system: "Engine", "Cooling system", etc. In brackets references to the corresponding Chapters and sections of the Management concerning functioning of the components suspected of malfunction are given.

Regardless of the refusal nature investigations of its reason are always taken the identical basic principles as a principle:

Make sure of correctness of definition of symptoms of refusal. Told means confidence in delimitation of the area of searches that it is especially important with the help in refusal diagnostics to other motorist who cannot adequately state symptoms of the violation taking place.

Try not to miss obvious violations. For example, if the engine is not started, do not hesitate to check availability of fuel in a gasoline tank (at the same time it is not necessary to take on trust statements of the owner of the faulty car). In case of refusal electric equipments first of all it is necessary to check a state and reliability of fastening of terminal connections of an electrical wiring, only after it it makes sense to get diagnostic units.

Try to remove a cause of failure, but not its symptom. Replacement of the discharged battery new will help to make start of the engine, however the reason of a discharge of the old battery taking place will remain not eliminated that will lead to bystry failure and new. Also replacement of the spark plugs thrown by oil will allow to restore serviceability of functioning of the engine for some time, however the refusal by all means will soon repeat (if the reason lay not just in application of candles not of that type).

Do not take on trust any statements. Remember that the "new" component can also be faulty, in particular if it long time lay in a luggage carrier — it is not necessary to exclude a component from the list checked only for the reason that it is new or is recently established. In case of neglect it is not necessary to be surprised with implementation of this recommendation when the cause of failure established, at last, is lying on a surface from the very beginning.

Failure diagnostics and reasons of decrease in efficiency of return of the engine

The engine is not turned in attempt of its start

• Polar plugs of the battery are oxidized, or fastening of tips of wires on them weakened (see the Head Routine maintenance).
• The battery is discharged or faulty.
• AT is not transferred to situation "P" or "N".
• It is torn off, or the electrical wiring of a chain of system of start is otherwise damaged, or fastening of plugs of contact connections weakened.
• The driving gear wheel of a starter is jammed in a gear wreath of a driving disk.
• The traction relay of a starter failed.
• The starter electric motor is faulty.
• The ignition switch is faulty.
• Teeth of a driving gear wheel of a starter or gear wreath of a driving disk are broken off or worn-out.
• The engine is jammed. Try to turn it manually for a bolt of a pulley of a bent shaft.

The engine is turned, but not started

• The fuel tank is empty.
• The battery is discharged (the engine is turned too slowly).
• Polar plugs of the battery are oxidized, or fastening of tips of wires on them weakened.
• Passability of fuel lines is broken, the gasoline pump is faulty, or ventilating branch pipes of the fuel tank are blocked.
• Ignition distributor components are faulty.
• Fell, or compression pressure is distributed between engine cylinders unevenly.
• Hydraulic pushers of valves are faulty.
• Water got to fuel.
• The ignition coil is faulty.
• The injection injector(s) is faulty.
• Components of system of ignition are humidified or damaged.
• Spark plugs are worn-out or damaged, or installation of interelectrode gaps is broken.
• The electrical wiring of a chain of system of start is torn off or is otherwise damaged, or fastening of plugs of contact connections weakened.
• As a result of weakening of fixture of the distributor installations of a corner of an advancing of ignition are broken.
• The electrical wiring of a chain of system of ignition is torn off or is otherwise damaged, fastening of plugs of contact connections weakened, or the ignition coil is faulty.
• Installations of phases of gas distribution are broken as a result of wear of components of the GRM drive.
• The gas-distributing belt is torn off, or the effort of its tension weakened.

Start of the cold engine is complicated

• The battery is discharged.
• Polar plugs of the battery are oxidized, or fastening of tips of wires on them weakened.
• Spark plugs are worn-out or damaged, or installation of interelectrode gaps is broken.
• The fuel supply system is faulty.
• Leak of fuel through an injection injector(s) takes place.
• Breakdowns of the runner of the distributor in the form of coal paths take place.
• Compression pressure fell.

Start of the hot engine is complicated

• The filtering air cleaner element is polluted, or its passability is otherwise broken.
• The power supply system is faulty (fuel does not come to injection injectors).
• Terminal connections of the battery are oxidized (especially weight).
• Quality of grounding of the power unit is broken.
• The CMP sensor in the ignition distributor is faulty.
• Serviceability of functioning of system of injection or engine management is broken.
• The system of catching of fuel evaporations (EVAP) is faulty.
• Compression pressure fell.

Input of a starter in gearing is complicated, or is followed by extraneous noises

• Teeth of a driving gear wheel of a starter or gear wreath of a driving disk are broken off or worn-out.
• Bolts of fastening of a starter weakened or dropped out.
• Internal components of a starter are worn-out or damaged.

The engine is started, but at once becomes deaf

• The electrical wiring of a chain of system of ignition is torn off or is otherwise damaged, or fastening of plugs of contact connections on the distributor, the coil of ignition or the generator weakened (see the Head Sistemy of start and a charge).
• Fuel starvation of an injector(s) of injection takes place.
• Depression losses take place.
• Installation of turns of idling is broken.
• Leak of the soaked-up air take place, or vacuum lines are damaged.

During the parking under the engine are formed begin to flow oils

• Leaks through laying of the pallet of a case, or a drain stopper take place.
• Takes place of leak through landing consolidation of the sensor of the switch of pressure of oil.
• Leaks through laying of heads of cylinders take place.
• Leaks through epiploons of shaft of the engine take place.
• Leaks in the oil pump take place.

Stability of turns of idling is broken

• Depression losses take place.
• The valve of system of recirculation of the fulfilled gases (EGR) is faulty.
• Passability of the PCV valve is broken.
• The filtering air cleaner element is blocked.
• The gasoline pump does not provide the required fuel consumption.
• Tightness of laying of a head of cylinders is broken.
• The GRM drive belt is worn-out.
• Working ledges of cams of the camshaft(s) are worn-out.
• Hydraulic pushers are faulty.
• Valves burned through, or leaky nestle on saddles.
• Installation of a corner of an advancing of ignition is broken.
• Serviceability of functioning of system of ignition is broken.
• Serviceability of functioning of the thermostatic air cleaner is broken.
• Spark plugs are worn-out or damaged, or installation of interelectrode gaps is broken.
• Fell, or compression pressure is distributed between cylinders unevenly.
• Passability of an injector(s) of injection is broken.
• Installation of turns of idling is broken.

Admissions of ignition on single turns take place

• Spark plugs are worn-out or damaged, or installation of interelectrode gaps is broken.
• VV of a wire of spark plugs are faulty.
• Components of system of ignition (distributor) are humidified or damaged.
• Short circuit in an ignition chain (the coil or candles) takes place.
• Components of system of decrease in toxicity are faulty, or their passability is broken.
• Passability of the fuel filter is broken, or fuel is polluted.
• Depression losses take place.
• Installations of turns or quality of mix of idling are broken.
• Installation of a corner of an advancing of ignition is broken.
• Fell, or compression pressure is distributed between cylinders unevenly.
• Passability of fuel injectors is broken.

Admissions of ignition take place at the movement on transfer

• Passability of the fuel filter / a connecting path of a power supply system is broken.
• Fuel pressure fell.
• Spark plugs are worn-out or damaged, or installation of interelectrode gaps is broken.
• Installation of a corner of an advancing of ignition is broken.
• The ignition distributor cover is burst, reliability of fastening of the VV contact connections of wires is broken, or internal defects of the distributor take place.
• "Breakdown" in VV candle wires takes place.
• Components of systems of decrease in toxicity of the fulfilled gases are faulty.
• Fell, or compression pressure is distributed between cylinders unevenly.
• The system of ignition is faulty, or contact connections of its electrical wiring weakened.
• Depression losses take place.
• The fuel pump is faulty, or the pressure developed by it fell.
• Ventilation of the fuel tank is broken.

Idling turns are excessively high

• Smoothness of the course of the drive of a butterfly valve is broken.
• Installation of turns of idling is broken.
• Leaks in the inlet air highway take place.
• Serviceability of functioning of a control system of the engine is broken.

The battery does not "hold" a charge

• The driving belt of the generator is worn-out, or adjustment of effort of its tension is broken.
• Polar plugs are oxidized, or fastening of tips of wires on them weakened.
• Electrolyte level fell in banks.
• The generator does not give the required charge current.
• The electrical wiring of a chain of system of a charge is torn off or is otherwise damaged, or fastening of plugs of contact connections weakened.
• There is a battery discharge owing to short circuit in an onboard electrical wiring.
• Internal defect of the battery takes place.

The control lamp of an ignition / charge continues to burn at the working engine

• Internal defect of the generator or regulator of tension takes place.
• The driving belt of the generator is worn-out or torn off, or adjustment of effort of its tension is broken.
• Generator brushes are worn-out, jammed or polluted.
• Brush springs of the generator weakened or are broken.
• The charge contour electrical wiring is torn off, or fastening of terminal connections weakened.

The control lamp of an ignition / charge does not light up at turn of a key in position of ON

• Incandescence thread fused.
• The printed circuit board of a combination of devices, or lamp holder is faulty.
• The generator is faulty.

Admissions of ignition take place during the movement

• Passability of the fuel filter is broken, or fuel is polluted.
• Spark plugs are worn-out or damaged, or installation of interelectrode gaps is broken.
• Installation of a corner of an advancing of ignition is broken.
• The distributor cover is burst, quality of the VV contact connections of wires is broken, or internal defect of the distributor of ignition takes place.
• Candle wires are damaged.
• Serviceability of functioning of components of system of decrease in toxicity of the fulfilled gases is broken.
• Fell, or compression pressure is distributed between cylinders unevenly.
• The ignition coil is faulty.
• Serviceability of functioning of system of ignition is broken.
• Losses of depression in the inlet pipeline, or through connecting vacuum hoses take place.
• Passability of injectors of injection is broken.
• Leaks in the EGR valve take place.
• Installation of turns of idling is broken.

Stability of turns of the engine is broken during acceleration

• Installation of a corner of an advancing of ignition is broken.
• Serviceability of functioning of system of ignition is broken.
• Passability of injectors of injection is broken.
• Fuel pressure as a result of violation of serviceability of functioning of a gasoline pump or passability of fuel lines fell.
• Serviceability of functioning of injectors of injection, or control system of the engine is broken.
• Spark plugs are worn-out or damaged, or installation of interelectrode gaps is broken.
• Fastening of the socket(s) of an electrical wiring of an injector(s) of injection weakened.
• Passability of the fuel filter is broken.
• Leak of air in the inlet highway takes place.
• Serviceability of functioning of the EGR system is broken.

The engine works with breakthroughs at the accelerator pedal withheld not movably

• Leak of air in the inlet highway takes place.
• The gasoline pump, or the fuel pressure regulator is faulty.
• Fastening of the socket(s) of an electrical wiring of an injector(s) of injection weakened.
• Violations of functioning of a control system of the engine take place.

The engine spontaneously becomes deaf

• Installation of turns of idling is broken.
• Passability of the fuel filter is broken, or moisture got to a power supply system.
• Components of system of ignition (the distributor and VV of a wire) are humidified or damaged.
• Components of systems of decrease in toxicity of the fulfilled gases are faulty.
• Spark plugs are worn-out or damaged, or installation of interelectrode gaps is broken.
• VV of a wire of spark plugs are faulty.
• Losses of depression on the throttle case, the inlet pipeline or through connecting hoses take place.
• Hydropushers of valves are faulty.
• The fuel pump is faulty, or the pressure developed by it fell.
• Ventilation of the fuel tank is broken, or fuel pipes are blocked.
• Serviceability of functioning of system of injection or engine management is broken.

The power developed by the engine fell

• Installation of a corner of an advancing of ignition is broken.
• The excessive side play of a shaft of the distributor of ignition takes place.
• The distributor runner, its cover, VV candle wires or the coil of ignition is worn-out.
• Spark plugs are worn-out or damaged, or installation of interelectrode gaps is broken.
• The system of injection of fuel is faulty.
• The filtering air cleaner element is blocked.
• Brakes are jammed.
• The ATF level fell in AT.
• AT is faulty.
• Passability of the fuel filter is broken, or moisture got to a power supply system.
• Serviceability of functioning of the EGR system is broken.
• The car is fuelled by non-standard.
• Fell, or compression pressure is distributed between cylinders unevenly.
• The system of production of the fulfilled gases is blocked.
• The fuel pump is faulty, or the pressure developed by it fell.
• Leaks in the inlet air highway take place.
• Serviceability of functioning of system of injection or engine management is broken.

There are "shots" in a final path

• Serviceability of functioning of the EGR system is broken.
• Installation of a corner of an advancing of ignition is broken.
• Serviceability of functioning of the thermostat of the air cleaner is broken.
• Depression losses take place.
• Hydropushers of valves are faulty.
• Valvate springs are damaged, or there was "sticking" of valves.
• Leaks in the inlet air highway take place.
• Malfunction in a secondary (VV) contour of system of ignition (candle insulators, wire VV, the distributor cover / runner, etc.) takes place.
• The system of injection of fuel is faulty.

The engine works with breakthroughs at the accelerator pedal withheld not movably

• Leak of air in the inlet highway takes place.
• The gasoline pump is faulty.
• Fastening of the socket(s) of an electrical wiring of an injector(s) of injection weakened.
• Violations of functioning of a control system of the engine take place.

During acceleration or at increase in load of the engine there are knocks caused by too early ignition or a detonation

• Fuel not of that grade is filled.
• Installation of a corner of an advancing of ignition is broken.
• The excessive nagaroobrazovaniye in combustion chambers takes place.
• Non-standard spark plugs are established.
• The system of injection of fuel is faulty.
• Wire VV are damaged.
• Distributor components are worn-out or damaged.
• Serviceability of functioning of the EGR valve is broken.
• Depression losses take place.
• The detonation sensor is faulty.

The engine continues to work after switching off of ignition (diesel effect)

• Leaks in injectors take place.
• Excessively high turns of idling are exposed.
• Working temperature of the engine is excessively high.
• Installation of a corner of an advancing of ignition is broken.
• The excessive nagaroobrazovaniye on the bottoms of pistons takes place.
• There is "sticking" of valves.
• Hydropushers of valves are faulty.
• Serviceability of functioning of the EGR system is broken.

Pressure drop of motive oil takes place

• Oil level fell, or oil not of that grade is filled.
• Bearings of the engine and/or the oil pump are worn-out.
• The engine overheat takes place.
• The oil filter is blocked.
• Passability of the mesh filter of a maslozabornik is broken.
• Excessively low turns of idling are exposed.
• There was a short circuit in an electrical wiring braid.
• The oil pressure measuring instrument is faulty.

The consumption of motive oil is excessive

• The drain stopper of the pallet of a case weakened.
• Bolts of fastening of the pallet weakened, or its sealing laying is damaged.
• Bolts of fastening of a forward cover weakened, or its sealing laying is damaged.
• The forward or back epiploon of a bent shaft is damaged.
• Bolts of fastening of a cover of a head of cylinders weakened, or its sealing laying is damaged.
• Landing of an oil filter weakened.
• The effort of tightening of the sensor switch of pressure of oil weakened.
• Excessive wear of pistons or cylinders takes place.
• Piston rings are worn-out or damaged.
• Maslootrazhatelny caps of inlet and/or final valves are worn-out or damaged.
• Cores of valves are worn-out.
• The directing plugs of valves are worn-out or damaged.

Fuel consumption is excessive

• The filtering element of the air cleaner is polluted or its passability is otherwise broken.
• Installation of a corner of an advancing of ignition is broken.
• Installation of turns of idling is broken.
• Leaks in a fuel path take place.
• Passability of injectors is broken.
• Serviceability of functioning of system of injection of fuel or engine management is broken.
• Serviceability of functioning of systems of decrease in toxicity is broken.
• Pressure of a rating of tires is not enough, or wheels not of that standard size are established.
• Brakes "are taken".

Fuel leak (in salon and near the car distinctly smells of gasoline) take place

• The fuel tank, fuel pipes or their nipple connections are damaged mechanically or as a result of corrosion development.
• The fuel tank is overflowed.
• The filter of a coal adsorber of the EVAP system is blocked.
• Leaks in a path of the EVAP system take place.
• Internal components of injectors are damaged or excessively worn-out.
• Serviceability of functioning of system of injection of fuel is broken.

Different noise arising during the operation of the engine

• The loud deaf knock more often arising at acceleration indicates wear or damage of radical bearings, or uneven wear of a bent shaft.
• Similar described above, but a little more high-frequency, the sound which is also more often arising at acceleration speaks about possible wear of conrod bearings.
• The blocked metal knock amplifying at increase in turns of the engine and weakening in process of warming up of the last testifies excessive wear of pistons and walls of cylinders.
• The frequent clicking which is becoming frequent at acceleration speaks about wear of piston fingers or nests under their landing in pistons (the sound arises at each passing by the VMT corresponding piston).
• The metal clicking published by the water pump specifies wear of bearings and need of replacement of the last.
• The reason of frequent knock or clicking, the turns which are becoming frequent with increase, violation of adjustment of valvate gaps can be. Wiretap the valvate mechanism by means of a stethoscope/piece of a vacuum hose. If adjustment of valves does not lead to correction of a situation, it is necessary to check a condition of hydraulic pushers and other components of the valvate mechanism.

• Wear of a gas-distributing chain or violation of adjustment of its tension can be the cause of the uniform metal knock or a roar published by the GRM drive; check also a condition of asterisks.

Diagnostics of malfunctions of the cooling system

The engine overheat takes place

• Level of cooling liquid fell.
• The driving belt is damaged or adjustment of its tension is broken.
• Passability of a radiator is broken or its lattice is blocked.
• The water pump is faulty.
• The thermostat is faulty.
• Violation in a cooling system fan chain takes place.
• Mechanical damage of a krylchatka of the fan of the cooling system takes place.
• Tightness of landing of a cover of a radiator is broken.
• Installation of a corner of an advancing of ignition is broken.
• The path of the cooling system is blocked by an air stopper.
• Motive oil not of that grade is filled.
• Indications of the measuring instrument of temperature are inexact.

Overcooling takes place

• The thermostat is faulty.
• Indications of the measuring instrument of temperature are inexact.
• Violation in a cooling system fan chain takes place.

External leak of cooling liquid takes place

• Hoses of a cooling path are damaged mechanically or destroyed as a result of material aging, or collars of their fastening weakened.
• Epiploons of the water pump are worn-out or damaged (cooling liquid will exude through a control opening).
• Leak of cooling liquid from a radiator or a broad tank takes place.
• Drain or release traffic jams of a water shirt of the block of the engine are damaged.
• Tightness of landing of the sensor switch of temperature of cooling liquid is broken.
• Sealing laying of the block is damaged or cracks in casting take place.
• The radiator cover is faulty.
Boiling up of cooling liquid
• resulted from an overheat.

Internal leak of cooling liquid takes place

• Laying of a head of cylinders is punched.
• The head or the block of cylinders is burst.
• Bolts of fastening of a head of cylinders weakened.

Losses of cooling liquid take place

• In system the excessive amount of cooling liquid is filled in.
• Cooling liquid boils away as a result of an overheat.
• External or internal leak of cooling liquid takes place.
• The radiator cover is faulty.
• Pressure in the cooling system increases at the expense of a compression in cylinders as a result of emergence of cracks in a head or the block, or violations of integrity of sealing laying.

Circulation of cooling liquid is broken

• The water pump is faulty. Check by probing of the top radiator hose.
• Passability of a cooling path is broken.
• The tension of a belt of the drive of the water pump weakened.
• The thermostat is jammed.
• Level of cooling liquid fell.

Corrosion development takes place

• Cooling liquid is excessively polluted. Add in system only the distilled rain water.
• Antifreeze is excessively diluted.
• Replacement of cooling liquid and washing of a path is insufficiently often made.

Diagnostics of malfunctions of AT

Leakages of ATF

ATF usually differs in dark red color. It is not necessary to confuse traces of its leaks to those from motive oil (the last can communicate on a transmission case the running air stream).

For identification of a source of leak, first of all, it is necessary to clear a case of transmission and surfaces surrounding it of dirt and lubricant. Use qualitative degreaser or execute steam cleaning of the unit. Make on the car a short trip with a low speed of the movement (that traces of the leak taking place did not communicate far from its source). The car also establish to Poddomkratta it on props. Examine a transmission case, visually revealing leakage sources of ATF.

Most often act as those:

• Transmission case pallet: tighten fixture and/or replace sealing laying;
• Back lengthening of transmission: tighten fixture and/or replace an epiploon;
• Jellied mouth: replace a rubber cuff in the place of an entrance of a mouth to a transmission case;
• Ventilating tube: transmission is crowded and/or water got to a case;
• Speedometer junction point: replace a sealing ring in the place of an entrance of a driving cable to a transmission case.

ATF has brown color or smells of ashes

• The ATF level fell in transmission, or liquid burned and needs replacement.

There is no automatic switching of transmission to a low gear at full squeezing of the accelerator pedal

• Adjustment of a cable of the drive of a butterfly valve at inclusion of the kickdown (downshift) mode is broken.

The engine is started in the provision of transmission, excellent from "Р or "N"

• The sensor switch of permission of start is faulty, or its adjustment is broken.

Transmission "comes off" the chosen situation, switches hardly or with noise, or does not provide progress of the car forward or back

There is a set of the possible reasons listed refusals however only one of them - violation of the ATF level gets to the sphere of competence of the average amateur mechanic. Check, in case of need make adjustment level / replacement of liquid and the filter, in parallel check a condition of ATF. In all other cases the car should be driven away for diagnostics and recovery repair / replacement of transmission on car repair shop.

Diagnostics of malfunctions of the driveshaft

Leaks in a forward part of the driveshaft take place

• The back epiploon of transmission is damaged or worn-out. Check also a condition of a surface of the sliding fork.

At transfer inclusion (at the time of emergence of loading) there is a knock

• Fastening of components of a back suspension bracket weakened.
• Driveshaft bolts / nut weakened.
• Bearings of the cardan hinge(s) are worn-out or damaged.
• The metal gnash corresponding to the speed of the movement of the car takes place
• Bearings of the cardan hinge are worn-out (in).

Vibrations take place

• Establish a tachometer in interior of the car and during the movement try to define engine turns at which vibration reaches the maximum intensity, then switch transfer and bring engine turns to the same value.
• If vibration arises and reaches the maximum intensity at the same turns of the engine, irrespective of the chosen transfer, its source is NOT the driveshaft as the frequency of its rotation depends on the choice of the transfer relation.
• If switching of transfer leads to disappearance of vibration or noticeable decrease in its intensity (at the same turns of the engine), it is necessary to pass to checks of a state cardan вала:.
• Check the driveshaft for existence of signs of a bend and other deformations, in case of need make replacement
• Carefully clear a shaft. The stuck dirt can be a balancing cause of infringement.
• Estimate degree of wear of bearings of cardan hinges, in case of need make replacement of assemblies.
• Check balancing of the driveshaft or its connecting flange. Make sure of presence on the places of balancing small weights, remove a shaft and establish it, having turned on 180 °. If vibrations do not disappear, give a shaft to balancing.
• Check reliability of tightening of fixing bolts / nuts.
• At the corresponding complete set of the car estimate degree of wear of the central bearing.
• Check a condition of back plugs of transmission.

The scraping sound takes place

• Make sure that the dustproof cover of the sliding fork does not rub about a case of back lengthening of transmission.

Takes place howl or whistle

• At the corresponding complete set of the car the central bearing can be a source of similar sounds.

Diagnostics of malfunctions of the back bridge and main transfer

The extraneous noise identical at the movement on transfer and a setup takes place

• Natural road noise.
• Are worn-out, or tires are pumped incorrectly up.
• Wheel bearings are worn-out or damaged, or their tightness weakened.
• Oil level fell in differential.
• The differential is faulty.

The knock arising at start-off from the place or at gear shifting takes place

• The differential is faulty, or its adjustment is broken.

Foreign sounds arise during commission of turns

• The differential is faulty.

Vibrations take place

• See the subsection devoted to diagnostics of malfunctions of the driveshaft. If a shaft as it should be, a poddomkratta a car back also establish it on props (see the illustration Scheme of an Institution of Props for fixing of the car in the lifted situation) and manually estimate a condition of wheel bearings, in case of need make replacement.

Oil leak takes place

• The epiploon of the leading gear wheel of the main transfer is damaged.
• Epiploons of half shafts are damaged.
• Fixture weakened, or sealing laying of a cover of differential is damaged.
• The drain and/or jellied stopper of differential weakened.
• Passability of a ventilating sapun of differential is broken.

Diagnostics of malfunctions of the transfer case

Gear wheels jump out from gearing

• The size of a free wheeling of a control lever is broken.
• The control lever clings to the console.
• Fixture of support of a suspension bracket of the transfer case weakened, or fatigue deformation of material takes place.
• Internal components of the transfer case are worn-out, or adjustments are broken.

Switching of the modes is complicated

• Oil level fell.
• Internal components of the transfer case are worn-out, or adjustments are broken.

Extraneous noises take place

• Oil level fell in the transfer case.
• Existence of noise at the choice of the modes 4H and 4L and absence in the mode 2H tells them about existence of malfunction in components of forward differential or a forward axis.
• Existence of noise at the choice of any of the modes speaks about existence of malfunction in components of back differential or the back bridge.
• Existence of noise at the choice of the modes 4H and 2H and absence in the mode 4L tells them about existence of malfunction of internal components of the transfer case.

Diagnostics of malfunctions of the brake system

When braking course stability of the car is broken

• Tires are pumped incorrectly up.
• Adjustment of angles of installation of forward wheels is broken.
• On one axis of the car (forward or back) wheels of a different standard size are established.
• Brake blocks / boots from one of car boards are worn-out, damaged or greasy.
• Brake shoes or disk from one of car boards are excessively worn-out.
• Fixture of components of a forward suspension bracket weakened.
• It is faulty one or several brake mechanisms.
• Passability of brake lines is broken.
• Bolts of fastening of a support or board of the brake mechanism weakened.
• The support piston / the wheel cylinder of one of brake mechanisms is jammed, or its movement is complicated.
• From different boards of the car brake blocks / boots with frictional overlays of various type are established.
• Components of the steering drive or suspension bracket are worn-out or damaged.
• Adjustment of a pretightness of wheel bearings is broken.

During braking there are extraneous noises (a gnash or high-frequency squeal)

• Frictional overlays of brake shoes of forward wheels are worn-out — the sound is made by sensors of wear of blocks.
• Zapolirovana to gloss brake shoes are polluted or.
• The brake disk / drum — usually after the long parking of the car is damaged by corrosion.
• Between a disk and a board of the brake mechanism the foreign subject got (for example, a stone).
• The brake board is deformed.

The course of a brake pedal is excessively big

• Local violation in the brake system takes place.
• Level of hydraulic liquid fell in the GTTs tank.
• Air got to hydraulic system.
• Serviceability of functioning of automatic regulators of brake mechanisms is broken.
• The valve limiter is faulty.
• GTTs is faulty.
• The vacuum amplifier of brakes is faulty.

Softness of the course of a brake pedal at its squeezing takes place

• Air got to hydraulic system.
• Flexible brake hoses are damaged as a result of material aging.
• GTTs fixture weakened.
• GTTs is faulty.
• Installation of working gaps of brake blocks / boots is broken.
• Passability of an air vent of a cover of the GTTs tank is broken.
• Rubber brake lines are deformed.
• Sealing cuffs of supports are softened.
• Brake fluid needs replacement.

The stop of the car requires applying of excessively big effort to a brake pedal

See the reasons listed in the previous subsection plus the following:

• The vacuum amplifier of brakes is faulty.
• Frictional overlays of brake blocks / boots are excessively worn-out.
• The piston (i) of a support / the wheel cylinder is jammed.
• Frictional overlays of brake blocks / boots are polluted by oil or lubricant.
• Brake disks are damaged or worn-out.
• GTTs or support(s) / the wheel cylinder(s) is faulty.
• Are recently established and were not in time to be earned extra new brake blocks / boots.
• Local violation in the brake system takes place.

The pedal of a foot brake fails to a floor without resistance

• Liquid level fell in the GTTs tank, or leaks via pistons of supports / wheel cylinders take place.
• Brake lines are damaged, or their nipple connections weakened.

During braking there are pulsations of a pedal of a foot brake

• Wheel bearings are worn-out or damaged, or adjustment of their pretightness is broken.
• Components of a support of the brake mechanism are incorrectly installed, or between them foreign objects got.
• The excessive side beating of a brake disk / ovality of a drum takes place.
• Brake shoes are unevenly worn-out.

Brake pedal pulsations take place during sharp braking

• Consequence of correct functioning of ABS.

During braking there is a vibration transferred to a brake pedal or a steering wheel

• The excessive beating of a brake disk / deformation of the brake drum takes place.
• Frictional overlays of brake blocks / boots are worn-out.
• Bolts of fastening of a support / a brake board weakened.
• Components of a suspension bracket or the steering drive, or support are worn-out.

Brakes "are taken" (efficiency of return of the engine is reduced, wheels are excessively warmed during the movement)

• Adjustment of an output rod of a pedal of a foot brake is broken.
• Passability of the GTTs inlet union is broken.
• The GTTs piston is jammed in the cylinder.
• Brake blocks / boots are excessively worn-out.
• Cups of pistons in the main brake cylinder, or supports of brake mechanisms are deformed.
• Adjustment of the parking brake is broken.
• Adjustment of a pretightness of wheel bearings is broken.
• Adjustment of adjusting height of a pedal of a foot brake is broken.
• The wheel cylinder(s) is jammed.
• Adjustment of gaps of landing of boots in drums of brake mechanisms is broken.
• GTTs is faulty.
• Passability of brake lines is broken.

Back wheels are blocked at normal braking

• Tires are pumped excessively strongly up.
• Protectors are excessively worn-out.

Back wheels are blocked at emergency brake application

• Tires are pumped excessively strongly up.
• Protectors are excessively worn-out.
• Are polluted by oil of a block of brake mechanisms of forward wheels.
• GTTs, or assembly (i) of brake mechanisms is faulty.

The parking brake does not hold the car properly

• Adjustment of the drive of the parking brake is broken.

Diagnostics of malfunctions of a suspension bracket and steering

Course stability of the car is broken

• On one axis wheels of various standard size are established, or their tires are pumped up with various pressure.
• Defect of tires takes place.
• Components of a suspension bracket or the steering drive are worn-out.
• Adjustment of angles of installation of forward wheels is broken.
• Brake mechanisms of forward wheels "are taken".
• Adjustment of a pretightness of wheel bearings is broken.
• Screw springs are broken or "sank".
• Wheel nuts weakened.
• The geometry of a suspension bracket or the steering drive is broken as a result of accident.

The side play of wheels and the increased vibration of the car takes place

• Balancing of forward wheels is broken (vibration is most considerably transmitted through a steering wheel).
• Balancing of back wheels is broken (vibration is most considerably transmitted through a car body).
• Adjustment of a pretightness of wheel bearings is broken.
• Components of racks of a suspension bracket are worn-out.
• Wheel nuts weakened.
• Tires are pumped unequally up.
• Rims are damaged or deformed.
• Tires are damaged.
• Components of the steering drive or suspension bracket, or their spherical hinges and/or rubber-metal plugs are worn-out.
• The spherical support is worn-out.

During commission of turns and when braking there is "galloping" and/or rocking of the car

• Fastening of the stabilizer of cross stability weakened.
• Shock-absorbers are faulty.
• Screw springs / springs of a suspension bracket are broken or "sank".
• Components of the steering drive or suspension bracket, or their spherical hinges and/or rubber-metal plugs are worn-out.
• The car is overloaded.

Roving or the general course instability of the car takes place

• On one axis wheels of various standard size are established, or their tires are pumped up with various pressure.
• Balancing of wheels is broken.
• Tires are pumped unevenly up.
• Wheel nuts / bolts weakened.
• The lack of lubricant of CV JOINTS and tips of steering drafts takes place.
• Shock-absorbers are worn-out.
• Fastening of the stabilizer of cross stability weakened.
• Screw springs / springs are broken or "sank".
• Adjustment of angles of installation of forward wheels is broken.
• Components of the steering drive or suspension bracket, or their spherical hinges and/or rubber-metal plugs are worn-out.

Excessively hardly the steering wheel turns

• Level of liquid of system of hydrostrengthening of a wheel fell.
• Tires are pumped incorrectly up.
• The lack of lubricant of spherical support and tips of steering drafts takes place.
• Adjustment of angles of installation of forward wheels is broken.
• Adjustment of the steering mechanism is broken, or lubricant level fell.
• Adjustment of a pretightness of wheel bearings is broken.
• Components of the steering mechanism are worn-out or damaged.
• Interferes with rotation of a steering shaft the understeering switch.
• Tires are pumped too poorly up.
• Spherical support are worn-out or damaged.
• Components of the steering drive are worn-out or damaged.
• See also previous subsection.

The side play of a steering wheel is excessive

• Wheel bearings weakened.
• Plugs of components of a suspension bracket are worn-out.
• Adjustment of the steering mechanism is broken.
• Adjustment of angles of installation of forward wheels is broken.
• Fixture of assembly of the steering mechanism weakened.
• Components of the steering drive or suspension bracket are worn-out.

There is no hydraulic strengthening

• The belt of the drive of the steering pump is damaged, or adjustment of its tension is broken.
• Level of hydraulic liquid fell.
• Passability of hoses of system of strengthening of a wheel is broken.
• Air got to the hydraulic highway of system of strengthening of a wheel.
• The steering pump is faulty.
• The steering mechanism is faulty.

Serviceability of return of a steering wheel to rectilinear situation is broken

• Adjustment of angles of installation of forward wheels is broken.
• Tires are pumped too poorly up.
• Components of the steering mechanism are worn-out.
• Adjustment of a steering column is broken.
• Spherical support are worn-out or damaged.
• Components of the steering drive are worn-out or damaged.
• There was a loss of lubricant of components of the steering drive.
• Lubricant level fell in a case of the steering mechanism.
• The steering column is jammed.

The steering wheel rotates in different directions with various resistance

• Leaks in a case of the steering mechanism take place.
• Passability of hydraulic lines of system of strengthening of a wheel is broken.

The steering pump works with the increased noise

• The lack of oil of the pump takes place.
• Passability of hoses, or oil filter of the steering pump is broken.
• Fixture of a driving pulley is weakened.
• Adjustment of effort of a tension of a belt of the drive of the steering pump is broken.
• The steering pump is faulty.

The extraneous noises proceeding from a forward part of the car take place

• Tires are pumped incorrectly up.
• There was a loss of lubricant of spherical support or components of the steering drive.
• Fixture of the steering mechanism, components of the steering drive and suspension bracket is weakened.
• Support of shock-absorbers are worn-out.
• Shock-absorbers are damaged.
• Springs are damaged.
• Nuts of fastening of wheels weakened.
• Vents of back half shafts are worn-out or damaged.
• The axial side play of the back bridge is excessive.

During braking controllability of the car worsens

• Stupichny bearings of forward wheels are worn-out.
• Screw springs of a suspension bracket are broken or "sank".
• Deformation of brake disks / drums takes place.

The car excessively sank

• Overload.
• Shock-absorbers of rack-mount assemblies are worn-out.
• Screw springs of a suspension bracket are broken or "sank".

The gnash or other extraneous noises published by the steering mechanism takes place

• Fixture of assembly of the steering mechanism weakened.
• Internal damage of the steering mechanism takes place.

Excessive wear of tires takes place

The increased wear of an internal or external part of a protector

• Tires (wear of both edges) are pumped insufficiently up.
• Adjustment of angles of installation of forward wheels is broken.
• Components of the steering drive or suspension bracket, or their spherical hinges and/or rubber-metal plugs are worn-out.
• Speed on turns does not decrease.
• Mechanical violation of geometry of a suspension bracket as a result of accident takes place.

Scaly wear (obtrepyvaniye) of a protector

• Convergence installation is broken.

Wear of the central part of a protector

• Tires are pumped up too strongly.

Wear of the inner and outer edges of a protector

• Tires are pumped insufficiently strongly up.
• Shock-absorbers are worn-out.

Uneven wear of a protector

• Balancing of a tire / wheel is broken.
• Excessively side beating of a disk or tire.
• Shock-absorbers are worn-out.
• The tire is damaged.
• At the movement on a dry firm paving the all-wheel drive mode is not turned off.