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

1.6. Diagnostics of malfunctions of knots and car systems

The owners of cars who are carrying out procedures of routine maintenance of a vehicle Routine maintenance of the schedule extremely seldom agrees given in Head will be compelled to address to materials of this section. Reliability of knots and the components established on modern cars is so high that at timely performance of replacement of the materials of details worn out and failed as a result of aging the probability of their sudden refusal is smallest. Refusals seldom occur spontaneously and usually are a consequence sometimes of long development of defect. In particular, failure of mechanical components practically always is preceded by emergence and development of the characteristic symptoms which are showing sometimes for many thousand kilometers of run to the full. The same components which can fail unexpectedly, usually are not vital for functioning of the main knots and car systems, 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 appears lying on a surface, however in certain cases it is necessary to work, making small investigation. The motorist who has made half-dozens of casual checks, replacements and corrections quite has chance to find a cause of failure (or its symptom), however in any way it is impossible to call such approach reasonable, in view of its labor input and aimlessness of expenses of time and means. There is a quiet logic approach to search of the failed knot or a component much more effectively. Surely it is necessary to take into consideration everything preceding breakage, sometimes insignificant, symptoms and guarding signals, such as loss of capacity 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 the hidden violation.

Below rather simple scheme of diagnostics of most often meeting refusals is provided in this subsection. 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 the sections of the Management concerning functioning of components suspected of malfunction are given.

Regardless of the refusal nature in a basis of investigation of its reason identical base principles are always put:

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

Try not to look through obvious violations. For example, if the engine is not started, do not hesitate to check availability of fuel in a fuel tank (thus it is not necessary to take on trust statements of the owner of the faulty car). In default electric equipments first of all it is necessary to check a condition and reliability of fastening of terminal connections of electroconducting, after it it is meaningful to get diagnostic devices.

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

Do not take on trust any statements. Remember that the "new" component also can appear 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 the made recommendation, when the cause of failure revealed, at last, will appear lying on a surface from the very beginning.

Problem 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 weakened fastening of tips of wires on them (see. Head Routine maintenance).
• The battery is discharged or faulty.
• AT is not transferred to the situation "R" or "N".
• It is torn off, or electroconducting of a chain of system of start is otherwise damaged, or weakened fastening of plugs of contact connections.
• 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 electromotor 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 cranked shaft.

The engine is turned, but not started

• The fuel tank is empty.
• The battery (the engine is turned too slowly) is discharged.
• Polar plugs of the battery are oxidized, or weakened fastening of tips of wires on them.
• Passableness of fuel lines is broken, the gasoline pump is faulty, or ventilating branch pipes of a fuel tank are blocked.
• Components of the distributor of ignition are faulty.
• Fell, or kompressionny pressure is non-uniformly distributed between engine cylinders.
• Hydraulic pushers of valves are faulty.
• Water got to fuel.
• The ignition coil is faulty.
• The injector (û) injection 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.
• Electroconducting of a chain of system of start is torn off or is otherwise damaged, or weakened fastening of plugs of contact connections.
• As a result of weakening of fixture of the distributor installations of a corner of an advancing of ignition are broken.
• Electroconducting of a chain of system of ignition is torn off or is otherwise damaged, weakened fastening of plugs of contact connections, or the ignition coil is faulty.
• Installations of phases of a gazoraspredeleniye are broken as a result of wear of components of a drive of GRM.
• The gas-distributing belt is torn off, or weakened effort of its tension.

Start of the cold engine is complicated

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

Start of the hot engine is complicated

• The filtering element of an air purifier is polluted, or its passableness is otherwise broken.
• The power supply system (fuel does not arrive in injection injectors) is faulty.
• Terminal connections of the battery (especially weight) are oxidized.
• 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.
• Kompressionny pressure fell.

Starter input in gearing is complicated, or is accompanied by extraneous noise

• Teeth of a driving gear wheel of a starter or gear wreath of a driving disk are broken off or worn-out.
• Weakened or blurt out bolts of fastening of a starter.
• Internal components of a starter are worn-out or damaged.

The engine is started, but at once ãëîõíåò

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

During a 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 leaks 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 a retsirkulyatsiya of the fulfilled gases (EGR) is faulty.
• Passableness of the PCV valve is broken.
• The filtering element of an air purifier is blocked.
• The gasoline pump does not provide demanded fuel consumption.
• Tightness of laying of a head of cylinders is broken.
• The belt of a drive of GRM is worn-out.
• Working ledges of cams of a camshaft (îâ) 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 a thermostatic air purifier is broken.
• Spark plugs are worn-out or damaged, or installation of interelectrode gaps is broken.
• Fell, or kompressionny pressure is non-uniformly distributed between cylinders.
• Passableness of an injector (îâ) injection is broken.
• Installation of turns of idling is broken.

Ignition admissions 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.
• System components ignitions (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 passableness is broken.
• Passableness of the fuel filter is broken, or fuel is polluted.
• Depression losses take place.
• Installations of turns or quality of a mix of idling are broken.
• Installation of a corner of an advancing of ignition is broken.
• Fell, or kompressionny pressure is non-uniformly distributed between cylinders.
• Passableness of fuel injectors is broken.

Admissions of ignition take place at movement on transfer

• Passableness of the fuel filter / a connecting path of a power supply system is broken.
• Pressure of fuel 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 cover of the distributor of ignition is burst, reliability of fastening of contact connections of VV 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 kompressionny pressure is non-uniformly distributed between cylinders.
• The ignition system is faulty, or weakened contact connections of its electroconducting.
• Depression losses take place.
• The fuel pump is faulty, or the pressure developed by it fell.
• Ventilation of a fuel tank is broken.

Idling turns are excessively high

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

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 weakened fastening of tips of wires on them.
• Electrolit level fell in banks.
• The generator does not give out a demanded current of a charge.
• Electroconducting of a chain of system of a charge is torn off or is otherwise damaged, or weakened fastening of plugs of contact connections.
• There is a battery discharge owing to short circuit in onboard electroconducting.
• 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 tension regulator 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.
• Shchetochny springs of the generator weakened or are broken.
• Electroconducting of a contour of a charge is torn off, or weakened fastening of terminal connections.

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

• Fused an incandescence thread.
• The printed-circuit board of a combination of devices, or a lampoderzhatel is faulty.
• The generator is faulty.

Ignition admissions take place during movement

• Passableness 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 contact connections of VV 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 kompressionny pressure is non-uniformly distributed between cylinders.
• The ignition coil is faulty.
• Serviceability of functioning of system of ignition is broken.
• Depression losses in the inlet pipeline, or through connecting vacuum hoses take place.
• Passableness 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.
• Passableness of injectors of injection is broken.
• Pressure of fuel as a result of violation of serviceability of functioning of a gasoline pump or passableness 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.
• Weakened socket fastening (îâ) injector electroconductings (îâ) injection.
• Passableness of the fuel filter is broken.
• Leakages of air in an inlet path take place.
• Serviceability of functioning of EGR system is broken.

The engine works with breakthroughs at a pedal of an accelerator withheld motionlessly

• Leakages of air in an inlet path take place.
• The gasoline pump, or regulator of pressure of fuel is faulty.
• Weakened socket fastening (îâ) injector electroconductings (îâ) injection.
• Violations of functioning of a control system by the engine take place.

Engine spontaneously ãëîõíåò

• Installation of turns of idling is broken.
• Passableness of the fuel filter is broken, or moisture got to a power supply system.
• Components of system of ignition (the distributor and wire VV) 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.
• Depression losses 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 a fuel tank is broken, or gasoline pipe lines are blocked.
• Serviceability of functioning of system of injection or engine management is broken.

The capacity developed by the engine fell

• Installation of a corner of an advancing of ignition is broken.
• Takes place excessive ëþôò a shaft of the distributor of ignition.
• The distributor begunok, its cover, VV candle wires or the ignition coil 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 element of an air purifier is blocked.
• Brakes are jammed.
• ATF level fell in AT.
• AT is faulty.
• Passableness of the fuel filter is broken, or moisture got to a power supply system.
• Serviceability of functioning of EGR system is broken.
• The car is filled with non-standard fuel.
• Fell, or kompressionny pressure is non-uniformly distributed between cylinders.
• The system of production of the fulfilled gases is blocked.
• The fuel pump is faulty, or the pressure developed by it fell.
• Leaks in an inlet air path 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 EGR system is broken.
• Installation of a corner of an advancing of ignition is broken.
• Serviceability of functioning of the thermostat of an air purifier is broken.
• Depression losses take place.
• Hydropushers of valves are faulty.
• Klapanny springs are damaged, or there was "zalipaniye" of valves.
• Leaks in an inlet air path take place.
• Malfunction in secondary (VV) a contour of system of ignition (candle insulators, wire VV, a distributor cover / begunok, etc.) takes place.
• The system of injection of fuel is faulty.

The engine works with breakthroughs at a pedal of an accelerator withheld motionlessly

• Leakages of air in an inlet path take place.
• The gasoline pump is faulty.
• Weakened socket fastening (îâ) injector electroconductings (îâ) injection.
• Violations of functioning of a control system by the engine take place.

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

• Fuel not 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 ignitions (diesel engine effect)

• Leaks in injectors take place.
• Excessively high turns of idling are exposed.
• The 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 "zalipaniye" of valves.
• Hydropushers of valves are faulty.
• Serviceability of functioning of EGR system is broken.

Pressure drop of impellent oil takes place

• Oil level fell, or oil not 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.
• Passableness of the mesh filter of a maslozabornik is broken.
• Excessively low turns of idling are exposed.
• There was a short circuit in an electroconducting plait.
• The measuring instrument of pressure of oil is faulty.

The consumption of impellent oil is excessive

• The drain stopper of the pallet of a case weakened.
• Weakened bolts of fastening of the pallet, or its sealing laying is damaged.
• Weakened bolts of fastening of a forward cover, or its sealing laying is damaged.
• The forward or back epiploon of a cranked shaft is damaged.
• Weakened bolts of fastening of a cover of a head of cylinders, or its sealing laying is damaged.
• Landing of the oil filter weakened.
• Weakened effort of a tightening of the sensor switch of pressure of oil.
• 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.
• Directing plugs of valves are worn-out or damaged.

Fuel consumption is excessive

• The filtering element of an air purifier is polluted or its passableness 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.
• Passableness 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 does not suffice, or wheels not that standard size are established.
• Brakes "are taken".

Leakages of fuel (in salon and near the car distinctly smells as gasoline) take place

• The fuel tank, gasoline pipe lines or their shtutserny connections are damaged mechanically or as a result of corrosion development.
• The fuel tank is overflowed.
• The filter of a coal adsorber of EVAP system is blocked.
• Leaks in an EVAP system path 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 at operation of the engine

• The loud deaf knock more often arising at acceleration, indicates wear or damage of radical bearings, or non-uniform wear of a cranked shaft.
• Similar described above, but a little more high-frequency, the sound, also is more often arising at acceleration, speaks about possible wear of shatunny bearings.
• The being blocked metal knock amplifying at increase of 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 the clicking which is becoming frequent with increase of turns, violation of adjustment of klapanny gaps can be. Hear to the klapanny mechanism by means of a stethoscope/piece of a vacuum hose. If adjustment of valves does not lead to situation correction, it is necessary to check a condition of hydraulic pushers and other components of the klapanny mechanism.

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

Diagnostics of malfunctions of system of cooling

The engine overheat takes place

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

Overcooling takes place

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

External leakages of cooling liquid take place

• Hoses of an okhladitelny path are damaged mechanically or destroyed as a result of material aging, or weakened collars of their fastening.
• Epiploons of the water pump (cooling liquid will exude through a control opening) are worn-out or damaged.
• Leakages of cooling liquid from a radiator or a broad tank take place.
• Drain or vyzhimny 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 molding take place.
• The radiator cover is faulty.
• There was a boiling up of cooling liquid as a result of an overheat.

Internal leakages of cooling liquid take place

• Laying of a head of cylinders is punched.
• The head or the block of cylinders is burst.
• Weakened bolts of fastening of a head of cylinders.

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 leakages of cooling liquid take place.
• The radiator cover is faulty.
• Pressure in system of cooling raises 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 a proshchupyvaniye of the top radiatorny hose.
• Passableness of an okhladitelny path is broken.
• Weakened a tension of a belt of a drive of the water pump.
• 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 path washing is insufficiently often made.

Diagnostics of malfunctions of AT

Leakages of ATF

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

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 greasing. Use a qualitative obezzhirivatel or execute steam cleaning of the unit. Make on the car a short trip with low speed of movement (that traces of taking place leak did not communicate far from its source). To Poddomkratta the car also establish it on props. Examine a transmission case, visually revealing sources of leakage of ATF.

Most often as those act:

• Pallet of a case of transmission: 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 a place of an entrance of a mouth in a transmission case;
• Ventilating tube: transmission is overflowed and/or water got to a case;
• Speedometer junction point: replace a sealing ring in a place of an entrance of a driving cable in a transmission case.

ATF has brown color or smells as ashes

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

There is no automatic switching of transmission on a low gear at complete squeezing of a pedal of gas

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

The engine is started in the provision of transmission, excellent from «R or «N»

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

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

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

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

• Weakened fastening of components of a back suspension bracket.
• Weakened driveshaft bolts / nut.
• Bearings of the kardanny hinge (îâ) are worn-out or damaged.
• The metal gnash conformable to speed of movement of the car takes place
• Bearings of the kardanny hinge are worn-out (in).

Vibrations take place

• Establish in car salon a tachometer and during movement try to define engine turns at which vibration reaches the maximum intensity, then switch transfer and finish 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 frequency of its rotation depends on a choice of the transfer relation.
• If switching of transfer leads to disappearance of vibration or appreciable decrease in its intensity (at the same turns of the engine), it is necessary to pass to checks of a condition kardanny âàëà:.
• Check the driveshaft on existence of signs of a bend and other deformations, in case of need make replacement
• Carefully clear a shaft. The stuck dirt can be at the bottom of balancing violation.
• Estimate degree of wear of bearings of kardanny 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 balancing ãðóçèêîâ, remove a shaft and establish it, having turned on 180 °. If vibrations do not disappear, give a shaft to balancing.
• Check reliability of a 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 a 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 movement on transfer and nakaty takes place

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

The knock arising at a troganiye from a place or at gear shifting takes place

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

Extraneous 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, ïîääîìêðàòüòå a car back also establish it on props (see an illustration the Scheme of an institution of props for car fixing in the lifted situation) and manually estimate a condition of wheel bearings, in case of need make replacement.

Leakages of oil take place

• The epiploon of a leading gear wheel of the main transfer is damaged.
• Epiploons of semi-axes are damaged.
• Weakened fixture, or sealing laying of a cover of differential is damaged.
• The drain and/or jellied stopper of differential weakened.
• Passableness ventilating ñàïóíà differential is broken.

Diagnostics of malfunctions of a 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.
• Weakened fixture of support of a suspension bracket of a transfer case, or fatigue deformation of a material takes place.
• Internal components of a transfer case are worn-out, or adjustments are broken.

Switching of modes is complicated

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

Extraneous noise take place

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

Diagnostics of malfunctions of brake system

When braking course stability of the car is broken

• Tires are pumped incorrectly up.
• Adjustment of corners 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.
• Weakened fixture of components of a forward suspension bracket.
• It is faulty one or several brake mechanisms.
• Passableness of brake lines is broken.
• Weakened bolts of fastening of a support or a board of the brake mechanism.
• The support piston / the wheel cylinder of one of brake mechanisms is jammed, or its moving is complicated.
• From different boards of the car brake blocks / boots with frictional overlays of various type are established.
• Components of a steering drive or suspension bracket are worn-out or damaged.
• Adjustment of a pretightness of wheel bearings is broken.

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

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

The course of a brake pedal is excessively great

• Local violation in 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 a course of a brake pedal takes place at its squeezing

• Air got to hydraulic system.
• Flexible brake hoses are damaged as a result of material aging.
• Weakened GTTs fixture.
• GTTs is faulty.
• Installation of working gaps of brake blocks / boots is broken.
• Passableness of a ventilating opening of a cover of the GTTs tank is broken.
• Rubber brake lines are deformed.
• Sealing cuffs of supports are softened.
• Brake liquid needs replacement.

For a stop of the car applying of excessively big effort to a brake pedal is required

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 (and) a support / the wheel cylinder is jammed.
• Frictional overlays of brake blocks / boots are polluted by oil or greasing.
• Brake disks are damaged or worn-out.
• GTTs or support (û) / the wheel cylinder (û) is faulty.
• Are recently established and were not in time to be earned extra new brake blocks / boots.
• Local violation in 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 weakened their shtutserny connections.

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 established, or between them extraneous subjects got.
• Excessive lateral palpation brake disk / ovality of a drum takes place.
• Brake shoes are non-uniformly worn-out.

Pulsations of a pedal of a brake take place during sharp braking

• Consequence of serviceable functioning of ABS.

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

• Excessive palpation brake disk / deformation of a brake drum takes place.
• Frictional overlays of brake blocks / boots are worn-out.
• Weakened bolts of fastening of a support / a brake board.
• Components of a suspension bracket either steering drive, or support are worn-out.

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

• Adjustment of a target rod of a pedal of a foot brake is broken.
• Passableness 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 (û) is jammed.
• Adjustment of gaps of landing of boots in drums of brake mechanisms is broken.
• GTTs is faulty.
• Passableness of brake lines is broken.

Back wheels are blocked at normal braking

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

Back wheels are blocked at emergency braking

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

The parking brake does not hold the car properly

• Adjustment of a 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 a 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 steering drive are worn-out.
• Adjustment of corners 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 "gave".
• Weakened wheel nuts.
• The geometry of a suspension bracket or steering drive is broken as a result of failure.

Takes place ëþôò wheels and the increased vibration of the car

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

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

• Weakened fastening of the stabilizer of cross-section stability.
• Shock-absorbers are faulty.
• Screw springs / springs of a suspension bracket are broken or "gave".
• Components of a steering drive or suspension bracket, or their spherical hinges and/or rezinometallichesky plugs are worn-out.
• The car is overloaded.

Roving or the general course instability of the car takes place

• On one axis wheels of a various standard size are established, or their tires are pumped up with various pressure.
• Balancing of wheels is broken.
• Tires are pumped non-uniformly up.
• Weakened wheel nuts / bolts.
• The lack of greasing of CV JOINTS and tips of steering drafts takes place.
• Shock-absorbers are worn-out.
• Weakened fastening of the stabilizer of cross-section stability.
• Screw springs / springs are broken or "gave".
• Adjustment of corners of installation of forward wheels is broken.
• Components of a steering drive or suspension bracket, or their spherical hinges and/or rezinometallichesky 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 greasing of spherical support and tips of steering drafts takes place.
• Adjustment of corners of installation of forward wheels is broken.
• Adjustment of the steering mechanism is broken, or greasing level fell.
• Adjustment of a pretightness of wheel bearings is broken.
• Components of the steering mechanism are worn-out or damaged.
• To rotation of a steering shaft stirs podrulevy the switch.
• Tires are too poorly pumped up.
• Spherical support are worn-out or damaged.
• Components of a steering drive are worn-out or damaged.
• See also previous subsection.

It is excessive ëþôò a steering wheel

• Weakened wheel bearings.
• Plugs of components of a suspension bracket are worn-out.
• Adjustment of the steering mechanism is broken.
• Adjustment of corners of installation of forward wheels is broken.
• Weakened fixture of assembly of the steering mechanism.
• Components of a steering drive or suspension bracket are worn-out.

There is no hydraulic strengthening

• The belt of a drive of the steering pump is damaged, or adjustment of its tension is broken.
• Level of hydraulic liquid fell.
• Passableness 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 in rectilinear situation is broken

• Adjustment of corners of installation of forward wheels is broken.
• Tires are too poorly pumped 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 a steering drive are worn-out or damaged.
• There was a loss of greasing of components of a steering drive.
• Greasing 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.
• Passableness 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.
• Passableness of hoses, or the oil filter of the steering pump is broken.
• The fixture of a driving pulley is weakened.
• Adjustment of effort of a tension of a belt of a drive of the steering pump is broken.
• The steering pump is faulty.

The extraneous noise which are starting with a forward part of the car take place

• Tires are pumped incorrectly up.
• There was a loss of greasing of spherical support or components of a steering drive.
• The fixture of the steering mechanism, components of a steering drive and suspension bracket is weakened.
• Support of shock-absorbers are worn-out.
• Shock-absorbers are damaged.
• Springs are damaged.
• Weakened nuts of fastening of wheels.
• Shlitsa of back semi-axes are worn-out or damaged.
• It is excessive axial ëþôò the back bridge.

During braking controllability of the car worsens

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

The car excessively gave

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

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

• Weakened fixture of assembly of the steering mechanism.
• 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 corners of installation of forward wheels is broken.
• Components of a steering drive or suspension bracket, or their spherical hinges and/or rezinometallichesky plugs are worn-out.
• Speed on turns does not decrease.
• Mechanical violation of geometry of a suspension bracket as a result of failure 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 internal and external edges of a protector

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

Non-uniform wear of a protector

• Tire / wheel balancing is broken.
• Excessively lateral palpation of a disk or tire.
• Shock-absorbers are worn-out.
• The tire is damaged.
• At movement on a dry firm paving the all-wheel drive mode is not disconnected.