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