This Section proposes the simplest scheme for finding out the causes of malfunctions and failures occurring in the components and systems of the vehicle. Failures and their possible causes are divided into groups based on their relationship to certain components or vehicle systems, such as engine, cooling system, etc., in addition, the text provides links to Sections and Subsections related to these problems.
Remember that successfully completing a root cause troubleshooting is not black magic reserved for experienced professional mechanics, but is determined by a combination of specific knowledge and a patient, systematic approach to investigating the problem. You should always move from simple to complex, bring each check to its logical conclusion and try not to miss the obvious facts - anyone can forget to fill the fuel tank or leave the lights on at night.
Finally, you should always try to get a clear picture of the development of the malfunction and take appropriate steps to prevent recurrence. If the failure of the electrical equipment occurred due to a violation of the quality of the contact, check at the same time the condition of all other contacts and electrical connectors of the system. If the same fuse continues to blow several times in a row, there is no point in replacing it further - you must try to find out the cause of the failure. Remember that the failure of a minor component may be a sign of a malfunction of a more important node or the entire system.
Engine
If the engine does not start, analyze the situation. For an engine to start at all, two basic conditions must be met. A fuel-air mixture should flow into the cylinders, and a spark should be generated at the spark plug. Therefore, firstly, you should check whether fuel is supplied. How to do this is described in the section Power supply and exhaust systems.
To determine if a spark is being produced, all the candles should be unscrewed, inserted into the tips and individually applied to the mass. Note: To prevent damage to the catalytic converter, gasoline injection must be excluded. To do this, disconnect the plug connection of the injectors. If there is no spark, troubleshoot according to section Engine Electrical Systems.
Warning: Observe safety precautions when working with the electronic ignition system (chapter Engine Electrical Systems).
When doing this, do not hold the tip or ignition cable with your hands, but use well-insulated tongs. Have an assistant start the engine. If the spark does not slip, determine the problem by referring to the section Engine Electrical Systems.
Engine won't crank when trying to start it
1. The battery terminals are corroded or the wire lugs are loose on them. Check the condition of the terminals and lugs. Tighten the terminal clamps, if necessary, remove traces of corrosion.
2. The battery is discharged or defective. If the wire lugs are found clean and securely attached to the battery terminals, turn the ignition key to the ON position, then turn on the headlights and/or windshield wipers. If this electrical equipment does not function, the battery is dead.
3. Transmission incorrectly set to position "R" (AT) or into neutral (RKPP), or the clutch is not fully depressed.
4. The wiring in the starting system circuit is broken or the wires are loose at the terminals. Check if, when starting the engine, there is a voltage of at least 10 V at terminal 50 of the traction relay, which is necessary for retraction. Check the condition of the wires, terminals and electrical connectors of the battery, the starter traction relay and the ignition switch.
5. The starter gear is wedged in the flywheel ring gear. On models equipped with a manual transmission, put it in gear and, manually pulling it into the car, turn the engine over. At the first opportunity, remove the starter and check the condition of the gear and flywheel ring gear.
6. Faulty starter relay (chapter Engine Electrical Systems).
7. Faulty starter (chapter Engine Electrical Systems).
8. Faulty ignition switch.
Engine cranks but won't start
1. Wrong start up
Starting procedure for a gasoline engine:
Apply the parking brake, depress the clutch pedal. On models with АТ press and hold a brake pedal. On AT, set the selector to position "R" or "N". Don't give gas. Turn the ignition key and hold until the engine starts. If the engine does not start within 20 seconds or stops immediately, repeat the starting process with the gas pedal half pressed. As soon as the engine starts, release the ignition key.
In frost below -15°C and at an altitude of more than 1000 m above sea level: Start at least 10 seconds with the pedal half pressed.
Be sure to move on immediately. If it is very cold, let the engine run for 30 seconds.
If the engine does not start after 10 seconds, interrupt the start and repeat it after half a minute.
Warning: Several failed start attempts in a row can damage the catalytic converter as unburned fuel combusts explosively when heated in the catalytic converter.
Only on a hot engine after starting, add a little gas.
2. Faulty engine immobilizer.
3. Fuse defective:
- electric fuel pump;
- electronic injection system.
For checking fuses, refer to subsection Circuit breakers.
4. Empty fuel tank or poor quality fuel.
5. The air filter is heavily soiled. There are vacuum leaks in the air supply elements, malfunctions in the fuel injection and ignition control system.
6. Low battery (engine cranks too slowly). Check the functioning of the electrical equipment.
7. Battery terminal connections corroded or loose (refer to the previous section).
8. Fuel pump defective.
9. Damaged or excessively wet ignition system components (Chapter Engine Electrical Systems).
10. Worn or defective spark plugs or incorrectly set spark plug gap (Chapter Engine Electrical Systems).
11. Broken or disconnected wiring of the electric circuit of the starting system, or the fastening of the wires to the terminals is loose.
12. Broken or disconnected ignition coil circuit wiring or loose wires at coil terminals (Chapter Engine Electrical Systems).
13. Compression pressure too low. Replace the cylinder head gasket. Repair the engine if necessary.
Diesel engine:
14. Wrong startup
Starting procedure for a turbodiesel engine:
On a cold engine and when the outside temperature is below +8°C, apply the parking brake, depress the clutch pedal. On AT, set the selector to position "R" or "N" - RKPP. Turn the ignition key to position II and wait until the preheat indicator lamp goes out. Immediately after the control lamp goes out, start the engine without giving gas. If irregular flashes appear, do not turn off the starter until the engine runs evenly (no more than 30 s). If the engine does not start, repeat starting after half a minute as described above. In the process of pre-heating the engine, do not turn on current consumers (light, heated rear window).
On a cold engine and at an outside temperature above +8°C, as well as with a warm engine, preheating is not required. The engine can be started immediately. Don't give gas.
15. Faulty engine immobilizer.
16. Fuse defective:
- electric fuel pump;
- preheat systems.
17. The engine is not warmed up: check the correct operation of the preheater.
18. There is no voltage at the solenoid shut-off valve. Connect a voltmeter or LED probe to the switch. Turn on the ignition. The LED should light up. Otherwise, you need to find a break in the wiring and fix it.
19. Solenoid shut-off valve defective. Check the reliability of the fastening of the electromagnetic switch, check the contacts. Turn the ignition on and off. The switch should click.
20. There is damage in the fuel supply line or air in the lines:
- a) Pipelines or hoses are mechanically damaged or clogged. Clean fuel lines and bleed air from lines and filter.
- b) Fuel filter clogged. Replace filter element.
- c) In winter, the filter and piping should be checked for ice or wax. Put the car in a heated garage, add gasoline to the system.
- d) Clogged tank vent or fuel inlet strainer.
Clean out.
21. The adjustment of the start of fuel supply is knocked down. Check, make adjustments.
22. Faulty injectors. Check. Loosen the union nuts one by one - when the nut of the faulty cylinder is unscrewed, the engine speed will not drop.
23. Faulty high pressure fuel pump (injection pump). Install a new or known-good injection pump for testing.
24. Compression pressure too low. Replace the cylinder head gasket. Repair the engine if necessary.
The starter operates without cranking the engine
1. Stuck starter gear. Remove the starter (Chapter Engine Electrical Systems) and check its status.
2. Worn or damaged starter gear teeth or flywheel crown.
Difficulty starting a cold engine
1. The battery is discharged or insufficiently charged.
2. There is a malfunction of the components of the power system or electrical equipment.
3. Paraffin in the fine filter of a diesel engine. Replace filter element. Refuel with winter fuel, or dilute with gasoline
4. Faulty diesel engine glow plugs.
Difficulty starting a hot engine
1. Air filter blocked
2. There is a malfunction of the components of the power system or electrical equipment
3. Fuel does not reach injection system injectors
4. The fuel advance angle of the diesel engine has gone astray.
5. Low compression in the cylinders, faulty or misaligned injection pump of a diesel engine.
Starter engagement is too noisy or difficult
1. Worn or damaged starter gear teeth or flywheel crown.
2. Starter mounting bolts are missing or loose.
Engine starts but immediately stalls
1. Faulty engine immobilizer.
2. Faulty wiring or loose wires at the coil or generator terminals.
3. There is a malfunction of the components of the power system or electrical equipment
4. The basic settings of the electronic control unit are violated (ECM).
5. Damage to the exhaust system/catalytic converter.
6. Vacuum loss occurs through the sealing surfaces of the intake manifold or fuel injection unit. Make sure that the fixing bolts/nuts are securely tightened, check the fact and quality of fastening on your fittings on the inlet pipeline of all vacuum hoses. Check the condition of the hoses and the correct connection (exactly to your fittings).
The stability of the engine at idle is broken
1. There are vacuum losses. Make sure that the fixing bolts/nuts are securely tightened, check the fact and quality of fastening on your fittings on the inlet pipeline of all vacuum hoses. Listen to the running engine with a stethoscope or a piece of fuel hose. The presence of a hissing sound will reveal the source "leaks" vacuum. No less effective can be used for checking a solution of soapy water.
2. There is a malfunction of the components of the power system or electrical equipment
3. Controlled crankcase ventilation valve blocked
4. Air filter blocked
5. The fuel pump does not supply enough fuel to the injection system injectors
6. There are leaks from the cylinder head gasket. Measure the compression pressure in the engine cylinders.
7. Camshaft lobes worn out
Diesel engine:
8. The quality of the connections of the fuel hoses on the injection pump and the fuel filter is broken. Replace the fuel hoses, secure them with clamps, tighten the corner screws.
9. Mechanically damaged or loose fastening of the high-pressure fuel pump. Check fastening.
10. The connections of the return pipeline and the fuel supply pipeline are reversed. Put connections in place. The return pipe connection screw is marked "OUT".
11. There is a damage in the fuel supply line:
- a) Pipelines or hoses are mechanically damaged or clogged. Clear fuel pipelines.
- b) Fuel filter clogged. Replace filter element.
- c) In winter, the filter and piping should be checked for ice or wax. Put the car in a heated garage, add gasoline to the system.
- d) Clogged tank vent or fuel inlet strainer.
Clean out.
12. The adjustment of the start of fuel supply is knocked down. Check, make adjustments.
13. Faulty injectors. Check. Loosen the union nuts one by one - when the nut of the faulty cylinder is unscrewed, the engine speed will not drop.
14. Faulty high pressure fuel pump (injection pump). Install a new or known-good injection pump for testing.
Misfiring occurs when the engine is idling
1. Worn or dirty spark plugs or incorrectly set spark plug gap (Chapter Engine Electrical Systems).
2. There is a malfunction of the components of the power system or electrical equipment
3. Faulty spark plug wires (Chapter Engine Electrical Systems).
4. Filled with poor quality fuel. Fuel filter clogged.
5. There is a loss of vacuum in the intake manifold or through the hose connections
6. Insufficient or unevenly distributed compression pressure in the cylinders. Take a compression test
7. There are malfunctions in the engine control system.
Misfiring occurs when vehicle is in gear
1. Blocked fuel filter or contaminated fuel system
2. Faulty or dirty spark plugs or incorrect spark plug gap (Chapter Engine Electrical Systems).
3. There is a malfunction of the components of the power system or electrical equipment.
4. There is a defective spark plug wires (Chapter Engine Electrical Systems).
5. Components of systems of decrease in toxicity of the fulfilled gases are faulty.
6. Insufficient or unevenly distributed compression pressure between the cylinders. Remove spark plugs and measure compression pressure
7. Faulty ignition system (Chapter Engine Electrical Systems).
8. There is vacuum loss at the throttle body, intake piping, or through the vacuum hoses
Engine stalls
1. Idle speed control broken.
2. Blocked fuel filter and/or moisture or dirt in the fuel system
3. There is a failure of power system components or sensors
4. Components of systems of decrease in toxicity of the fulfilled gases are faulty.
5. Faulty or dirty spark plugs or incorrect spark plug gap. Also check the condition of the spark plug wires (Chapter Engine Electrical Systems).
6. There is vacuum loss at the throttle body or through the vacuum hoses
The engine does not develop full power
1. There is a malfunction of the components of the power system or electrical equipment (Chapter Engine Electrical Systems).
2. Air cleaner clogged. Clean or replace.
3. Faulty spark plugs or incorrect spark plug gap
4. Faulty ignition coil (Chapter Engine Electrical Systems).
5. AT fluid level does not meet the requirements
6. Clutch slips
7. Blocked fuel filter and/or dirt/moisture in the fuel system
8. Wrong grade of fuel filled. Fill the tank with fuel with the required octane rating.
9. Damaged turbocharger control valve.
10. Faulty timing camshaft actuator.
11. Insufficient or uneven compression pressure across the cylinders. Carry out a compression test, the analysis of the results of which reveals the presence of valve leaks and / or a leak in the cylinder head gasket
Optional for diesel engine
12. Air cleaner clogged. Clean or replace.
13. Uneven fuel supply of the injection pump to the cylinders. Adjust on a warm engine.
14. Incorrectly set the moment of the beginning of the injection of fuel injection pump. Install.
15. Clogged fuel filter or injection pump (nozzle). Flush pre-filter, change fine filter element, clean sprayer or replace pump (nozzle).
16. The adjustment of the maximum speed of the crankshaft is violated.
There are pops in the intake system or shots in the exhaust system
1. There is a malfunction of the components of the power system or electrical equipment (Chapter Engine Electrical Systems).
2. There is a defect in the secondary circuit of the ignition system (destruction of spark plug insulators or defects in spark plug wires) (Chapter Engine Electrical Systems).
3. The fuel injection system needs to be adjusted or its components are excessively worn
4. There is vacuum loss at the throttle body, intake piping, or through the vacuum hoses
5. Valves stuck
6. The order of connecting spark plug wires is violated (Chapter Engine Electrical Systems).
Detonation sounds occur when accelerating or going uphill
1. Filled with low quality fuel.
2. There is a malfunction of the components of the power system or electrical equipment (Chapter Engine Electrical Systems).
3. Wrong type spark plugs installed. Check spark plugs and coils for damage (Chapter Engine Electrical Systems).
4. The basic settings of the electronic control unit are violated.
5. Faulty knock sensor.
6. There are vacuum losses
There is an ignition (the engine continues to run after the ignition is turned off)
1. Excessively high idle speed.
2. There is a malfunction of the components of the power system or electrical equipment (Chapter Engine Electrical Systems).
3. Damaged EVAP adsorber purge valve (EVAP).
4. Excessive engine operating temperature. Possible causes of this problem could be a low coolant level, a failed thermostat, a blocked radiator, or a faulty water pump.
Diesel engine smokes
1. Black smoke:
- a) The air cleaner is dirty. Rinse and refill with fresh oil or replace element.
- b) Wrong fuel used. Flush the tank and change the fuel.
- c) Incorrectly set the moment of the beginning of the supply of high pressure fuel pump.
2. Blue smoke:
- a) Burning oil in the combustion chamber due to wear of the piston rings, high oil level in the air cleaner, wear of the seals in the turbocharger covers, the formation of leaks in the gasket between the crankcase and the turbocharger. Repair the engine, set the correct oil level, replace the oil seals, tighten the turbocharger mounting bolts or replace the gasket.
- b) No fuel is being supplied to one of the injectors. Check for heating of the manifold exhaust pipes.
- c) Poor atomization of fuel by the injector due to a valve malfunction or an atomizer break. Lap the valve or replace the nozzle.
3. White or brown smoke:
- a) Low temperature in the cooling system. Check thermostat.
- b) Poor operation of nozzles due to wear or breakage of the atomizer. Replace atomizer.
Engine electrical equipment
Battery not "keeps" charge
1. The alternator drive belt is worn or damaged, or its tension is not adjusted (Chapter Engine Electrical Systems).
2. Insufficient electrolyte level or severely discharged battery (Chapter Engine Electrical Systems).
3. Battery terminals are corroded or wire lugs are loose (Chapter Engine Electrical Systems).
4. The generator does not provide the required charge current (Chapter Engine Electrical Systems).
5. Charging circuit wiring broken or otherwise damaged, or wires loose at terminals
6. A short circuit in the wiring creates a permanent leakage of current generated by the battery to ground
7. There is an internal defect in the battery.
The ignition control lamp does not go out when the rpm is increased
1. Loose drive belt. Check the V-belt tensioner.
2. Overrunning clutch damage (only turbodiesel). Remove the generator and turn the generator drive shaft to the left. If the pulley face does not rotate, then the damage is usually in the freewheel.
3. Damage to the voltage regulator/generator. Disconnect the wire (D+) on the back of the generator and turn on the ignition. If now the control lamp does not light up, the fault is usually in the voltage regulator or in the generator.
4. Wear of brushes. Visually check the brushes, replace if necessary.
5. Regulator damage. Check, replace if necessary.
6. Generator damage. Check, replace if necessary.
7. Damage to the wire between the generator and the voltage regulator. Disconnect the blue wire at terminal 12 of the T32a connector and at the instrument panel unit. If now the control lamp does not light up, the D+ wire is connected to ground. Replace harness.
8. Damage to the instrument panel block. If, after disconnecting the blue wire from the T32a plug connection with the ignition on, the control lamp lights up, the malfunction is usually in the instrument panel unit.
The ignition control lamp does not light up when the ignition key is turned to "ON" (when the ignition is turned on)
1. The control lamp on the instrument panel burned out or otherwise failed.
2. Generator defective.
3. There is a defect in the printed circuit board, wiring inside the dashboard unit or lamp socket
The control lamp of a charge burns after switching off of ignition
Positive diodes have a short circuit. Check diodes, replace diode board.
Starter
If the starter does not crank, first check that the traction relay terminal 50 has the required voltage of at least 10 V. If the voltage is below this value, check the wires included in the starter current circuit according to the diagram.
Whether the starter engages at full battery voltage can be checked as follows:
- without engaging gears, turn on the ignition.
- bridge terminals 30 and 50 of the starter with a wire of at least 4 mm section2, refer also to Section "Checking the traction relay".
If the starter works flawlessly, the cause of the malfunction should be sought in the wires to the starter. If the starter does not work, it should be checked in the removed state.
Check condition: At the connection points, the wires must be well fixed and must not be oxidized.
The starter does not rotate when the ignition switch is turned on
1. Low battery. Charge the battery.
2. Bridge terminals 30 and 50 of starter: Starter turns. Broken wire 50 to the ignition switch, the starter switch is faulty. Repair break, replace defective parts.
3. Breakage of the cable or ground connector, the battery is discharged. Check battery cables and connectors, measure battery voltage, charge if necessary.
4. Insufficient current flow due to loose or oxidized connectors. Clean battery poles and terminals, check connections between battery, starter and ground.
5. There is no voltage at terminal 50 of the traction relay. Broken wire, starter switch defective.
The starter rotates slowly and does not turn the crankshaft
1. Battery discharge. Charge the battery.
2. Filled with summer oil. Fill with multigrade oil.
3. Insufficient current flow due to loose or oxidized connectors. Clean battery poles and terminals, check connections between battery, starter and ground.
4. The carbon brushes are loose on the commutator, stuck in the guides, worn, broken, oily or dirty. Check brushes, clean or replace. Check guides.
5. Insufficient distance between brushes and commutator. Replace brushes and clean brush guides.
6. Collector in grooves or burnt and oily. Treat manifold or replace anchor.
7. No voltage at terminal 50 (min. 8 V). Check the starter switch or traction relay.
8. Broken bearing. Check bearing, replace if necessary.
9. Faulty traction relay. Replace the traction relay.
The starter seizes and rotates the engine jerkily
1. Defective gear drive. Replace gear drive.
2. The gear is dirty. Clean the gear.
3. Flywheel ring gear defective. Process the ring gear, if necessary, replace the flywheel.
Starter gear does not move away from crown
1. Gear drive or threads are dirty or damaged. Clean or replace gear drive.
2. Faulty traction relay. Replace the traction relay.
3. The return spring is weak or broken. Replace return spring.
The starter continues to work after the ignition key is released
1. The traction relay is stuck, does not turn off. Immediately turn off the ignition, replace the traction relay.
2. The ignition switch does not turn off. Disconnect the battery immediately, replace the ignition switch.
Supply system
Excessive fuel consumption
1. Air filter element dirty or blocked.
2. There is a malfunction of the components of the power system, electrical equipment or electronic control
3. Leaks in the air intake system.
4. Damage to the exhaust system/catalytic converter.
5. Insufficient tire pressure or wrong size tires fitted.
diesel engine
6. Clogged return line. Blow out the return line from the injection pump to the fuel tank with air.
7. Too high idle speed and maximum speed. Adjust.
8. The engine has mechanical damage. Check compression, repair engine if necessary.
There are fuel leaks and/or a smell of gasoline
1. There are leaks in the fuel or vent lines
2. The fuel tank is full. Refuel only until the gun automatically shuts off.
3. There are leaks or evaporation from the lines of the power system and reduce the toxicity of exhaust gases.
Engine won't start
1. When the starter is turned on, the electric fuel pump does not work (no noise from work). Tap the pump body lightly to loosen the stuck part. Check if voltage is being applied to the pump. Check fuse. Check electrical contacts for good conductivity.
2. Faulty fuel pump relay. Check the relay.
3. Stuck injector valves. Check injectors, replace if necessary. Check the voltage supply to the injectors. To do this, disconnect the injector connector. Attach a diode test lamp to the wire and turn on the starter. The control lamp should flash.
4. There is no signal from the ignition timing sensors or the engine speed sensor. Check electrical wires. Interrogate the fault memory.
5. Fuel lines damaged, clogged or leaking, hoses defective.
6. Fuel filter clogged.
7. Presence of ice or wax in the filter or lines of the diesel engine.
8. The fuel tank vent is clogged, the filter in the tank is clogged.
9. Damaged diesel injectors. Loosen the union nuts one by one and check if the corresponding cylinder works.
Cold engine starts badly, works unstably
1. The CO content does not meet the requirements. Check CO content and idle speed.
2. Temperature sensor defective. Check the coolant/intake air temperature sensor.
3. The fuel pressure does not match the required value. Check fuel pressure.
Warm engine starts poorly, runs erratically
1. Leaky air intake system. Check intake system. To do this, leave the engine idling and cover the seals and connections on the intake tract with gasoline. If the speed increases for a short time, repair leaks.
Warning: Gasoline fumes are poisonous, do not inhale them.
Engine runs intermittently
1. The electrical connections to the fuel pump are interrupted from time to time. Check the condition of the plug connections and connectors of the electrical wires of the fuel pump, air flow meter and fuel pump relay. Check the fuse and contact points on the fuel pump relay. Clean contacts, replace if necessary.
2. Poor fuel quality, vapor lock formation. Refuel with quality fuel.
3. Fuel supply too low. Check pump performance.
4. Fuel filter defective. Replace fuel filter.
5. Fuel pump defective. Check fuel pump.
6. Faulty injectors. Check injectors.
7. Faulty throttle position sensor. Check throttle position sensor.
8. Weak fastening of the fuel hoses to the injection pump and the fuel filter of the diesel engine.
The engine runs intermittently during transients and idling
1. Leaky air intake system. Check intake system connections. Start the engine and lubricate the contact points and connections in the intake tract with gasoline. If the engine speed increases briefly, repair the leak.
2. Incorrect idle adjustment. Check idle air control, throttle position sensor, lambda control.
3. Full load sensor defective or incorrectly adjusted. Check the throttle sensor.
Hot engine won't start
1. Incorrect adjustment of the CO content. Check CO content and idle speed.
2. Too high pressure in the fuel system. Check fuel pressure, replace pressure regulator if necessary.
3. Clogged or bent return line between pressure regulator and fuel tank. Clean or replace piping.
4. Faulty engine temperature sensor. Check temperature sensor.
5. The power system is leaking. Make a visual inspection of all connections in the area of the engine and electric fuel pump. Tighten all connections.
6. Leaky air intake system. Check all intake system connections.
Engine running after shutdown
1. Leaky injectors. Check injectors.
2. The diesel engine does not have a fuel cut-off valve.
Lubrication system
The control lamp does not burn after inclusion of ignition
1. Defective oil pressure sensor. Turn the ignition on, disconnect the wire from the oil pressure sensor and short to ground. If the lamp lights up, replace the sensor.
2. The sensor is not energized, the contacts are corroded. Check electrical wires and contacts.
3. The control lamp is defective. Replace the control lamp.
4. Control device defective. Replace control device.
The control lamp does not go out after starting the engine
The oil is overheated. If the control lamp goes out after the gas is applied, nothing needs to be done.
The control lamp does not go out after applying gas or lights up while driving
1. The oil pressure is too low. Check oil level, top up if necessary. Check oil pressure.
2. The wire to the oil pressure sensor has a short to ground. Disconnect the cable from the sensor and lay it aside (without grounding), turn on the ignition. If the lamp lights up, check the wire.
3. The oil pressure sensor is defective. Replace sensor.
Too low oil pressure at all speeds
1. There is too little oil in the engine. Add oil.
2. The strainer is clogged. Remove the oil pan, clean the strainer.
3. Worn oil pump. Remove the oil pump and check it, replace if necessary.
4. Bearing damage. Remove the engine.
Too low oil pressure at low speeds
Pressure reducing valve stuck open due to contamination. Remove and check the valve.
Oil pressure too high above 2000 rpm
Pressure reducing valve does not open due to contamination. Remove and check the valve.
Cooling system
Overheat
1. Not enough coolant in the system
2. Worn or damaged water pump drive belt or incorrect tension adjustment
3. The internal channels of the radiator are blocked or dirty (blocked) radiator grille
4. Faulty thermostat.
5. Broken or cracked fan blades
6. Faulty viscous fan clutch. Check fan clutch: Increase engine speed when warm. As soon as the temperature of the liquid reaches 90 - 95°C, the fan speed will increase, which will be noticeable by ear.
7. Faulty coolant temperature gauge. Check sensor.
8. Coolant pump defective. Remove and check the pump.
9. The radiator cap is not holding pressure. Perform a pressure test on the cap (contact a service station).
Hypothermia
1. Faulty thermostat
2. Inaccurate temperature readings.
External coolant leaks
1. The hoses are damaged or destroyed as a result of aging of the material or their fastening on the fittings has loosened. Replace hoses and/or tighten hose clamps
2. Damaged water pump seals. In this case, the coolant will seep through the control hole in the pump housing
3. There are leaks from the internal channels of the radiator or side reservoir (ov). Professional Radiator Repair Needed
4. There are leaks from the engine drain plug or squeeze plugs of water galleries
Internal coolant leaks
Warning: Internal coolant leaks are usually detected by checking the condition of the engine oil. Inspect the feeler blade and inside surfaces of the cover (lids) cylinders for traces of water and oil foaming.
1. There are leaks from the cylinder head gasket. Perform a pressure test on the cooling system.
2. There are cracks in the cylinder walls or in the head casting. Disassemble the engine to check
Loss of coolant occurs
1. Too much refrigerant in the system
2. The cooler boils away as a result of engine overheating
3. There are internal or external refrigerant leaks
4. Radiator cap defective. Check the cover with pressure.
Refrigerant circulation interrupted
1. The water pump is not functioning properly. The easiest way to verify the operation of the pump is to pinch the upper radiator hose while the engine is idling. If a push of liquid is felt inside the hose when the hose is released, the pump is functioning properly
2. The patency of the cooling system is broken. Drain the coolant, flush the system and refill it with fresh mixture. If necessary, remove the radiator and backflush it.
3. Worn or damaged water pump drive belt or incorrect tension adjustment
4. Stuck thermostat.
Heater
Heater fan not working
1. Fan motor fuse defective. Check fan fuse, replace if necessary.
2. Faulty fan switch. Check if voltage is being applied to the pre-resistors, remove and check the fan switch.
3. Electric motor defective. Check if voltage is applied to the fan motor terminals with the ignition on and the fan switch closed. If voltage is applied, replace the motor.
The heater fan does not work on one of the stages
Faulty preresistor. Replace connection board.
The heater is not switched off by the regulator
1. Switch defective. Check switch.
2. Control mixing flap cables are damaged or not movable. Replace cables.
Heating power too low
1. Coolant level too low. Check coolant level, top up if necessary.
2. The heater control unit is hard to move, defective. Check the heater control unit, replace the cable if necessary.
Noise in the heater fan area
1. Got dirt, leaves. Remove the fan and clean it, clean the air channel.
2. Impeller imbalance, bearing failure. Remove the fan motor, check for ease of movement.
Clutch
Clutch does not disengage (the manual transmission control lever does not move freely into the reverse gear position and back when the clutch pedal is depressed to the floor)
Bent or damaged clutch disc
Clutch slips (engine speed increases without increasing vehicle speed).
1. The clutch disc is contaminated with oil or its friction linings are worn out. Remove the clutch and check the condition of its components.
2. Clutch disc not worn in properly. It may take 30 to 40 normal starts of the car to finally break in a new disc.
3. Worn pressure plate/clutch basket.
Vibration occurs when clutch is engaged
1. Oily clutch disc. Remove the clutch and check the condition of its components. Repair any leaks found.
2. Worn disc hub splines (clutch disc). Remove the clutch and check the condition of its components.
3. Bent pressure plate/clutch basket or flywheel. Remove the clutch and check the condition of its components and flywheel.
Jerks during clutch operation
1. Damage to engine and gearbox mounts. Check, replace if necessary.
2. Looseness of the gearbox mounting in the suspension. Tighten the mounting bolts.
3. Uneven pressure plate contact. Replace clutch basket.
4. The crankshaft is not centered with the gearbox. Check centering.
Squealing or rattling occurs when the clutch is fully engaged (pedal released)
Clutch release bearing stuck. Remove the clutch and check the condition of the bearing. Remove all burrs and nicks and lubricate the bearing before reinstalling.
Squealing or rattling occurs when the clutch is fully disengaged (pedal depressed)
1. Worn or damaged release bearing
2. Worn or damaged springs (or aperture blades) pressure plate in the clutch basket
Clutch pedal remains depressed to the floor after releasing it
Stuck clutch master or slave cylinder piston. Damage to the clutch hydraulic system or release bearing. Check the condition, if necessary, remove the clutch components.
Manual gearbox (RKPP)
When the gearbox is set to neutral, extraneous noises occur during engine operation
1. Worn input shaft bearing.
2. Drive shaft bearing damaged.
3. Worn intermediate shaft bearings.
4. Worn or damaged washers for adjusting the axial play of the intermediate shaft.
Extraneous noises occur in any position of the manual transmission
1. Any of the above reasons and/or:
2. Insufficient amount of gear oil is filled in the manual transmission (his level dropped).
Extraneous noise occurs in any particular gear
1. Worn, damaged or chipped gear teeth of this gear.
2. Worn or damaged synchronizer of this gear.
Going on "jumping off" Gearbox with top gear
Dirt has got between the gearbox boat and the engine or the gearbox has shifted in relation to the engine.
Complications occur when shifting gears
1. Not fully squeezed out (turned off) clutch.
2. shift rod damaged, loose or out of adjustment. Make a thorough check of the condition of the components, if necessary, replace the defective ones.
Transmission oil leaks
1. The gearbox has been filled with excessive gear oil. Drain excess if necessary.
2. The differential seals need to be replaced.
automatic transmission (AT)
Warning: Due to the complexity of the AT design, complete diagnostics of its malfunctions and repair of components are beyond the qualifications of the average amateur mechanic. In the event of any problems other than those listed below, the functioning of the AT, the car should be driven away for inspection and repair to a car service workshop or a representative office of AUDI A3.
General problems associated with the functioning of the switching mechanism
Among the failures associated with a violation of the adjustment of the shift rod are the following:
- a) The engine can be started in transmission positions other than "R" (parking) And "N" (neutral).
- b) The transmission position indicator reading is different from the actual gear selected.
- c) The vehicle is moving with the transmission in position "R".
Adjust the shift rod
Transmission slips, shifts hard, makes abnormal noises, or does not move the vehicle when set to one of the forward or reverse gears.
1. There are many possible causes of the problems listed in the title, but only one of them falls under the competence of an amateur mechanic - an incorrect transmission fluid level.
2. Before driving the car to a car service workshop, check the level and condition of the transmission fluid (Chapter 1). Correct the level in accordance with the requirements of the Specifications or change the fluid along with the filter. If the situation does not improve, seek help from specialists.
Transmission fluid leaks
1. AT fluid has a dark red color. Traces of its leaks should not be confused with traces of impellent oil, which can be carried to the transmission crankcase by the oncoming air flow.
2. To identify and locate the source of the leak, first remove all traces of dirt and grease from the transmission boat. Use a suitable degreaser and/or steam clean. Then drive the car for a short trip at low speed (so that traces of the leak are not carried away by the oncoming flow far from its source). Stop, jack up the vehicle and locate the source of the leak by visual inspection. Most often these are:
- a) Transmission sump: Tighten mounting bolts and/or replace sump gasket.
- b) Fluid Fill Tube: Replace the rubber seal where the tube enters the transmission case.
- c) Transmission Fluid Lines: Tighten fittings or replace lines.
- d) Vent tube: Transmission overfilled and/or water ingested.
Bridges
Extraneous noise
1. Ordinary road noise. Not subject to correction.
2. Tire noise. Check the condition of the treads and tire inflation pressure.
3. Worn or damaged wheel bearings or loose torque.
Vibrations
Check the condition of the wheel bearings by alternately jacking the appropriate corner of the car and rotating the wheel manually. Listen for sounds coming from the bearing. Remove the bearings and check their condition.
Oil leaks
Damaged drive shaft seals.
Brake system
Warning: Before concluding that there is a problem with the braking system, check that the tires are in good condition and inflated to the correct pressure, that the front wheel alignment is not misaligned, and that the vehicle is not loaded unevenly.
Increased brake pedal travel
The brake circuit has failed. Check if brake fluid is leaking.
Brake pedal springs and falls
1. Air in the brake system. Remove air from the system.
2. Not enough liquid in the reservoir. Add new brake fluid, remove air from the system.
3. The formation of steam bubbles. It appears mainly when the brakes are heavily loaded. Change the brake fluid, remove air from the system.
Decreased braking effect, pedal fails
1. Pipeline leakage. Tighten tubing connections or replace tubes.
2. Damage to the cuffs in the main or working brake cylinders. Replace cuff. In the main brake cylinder, replace the internal elements, if necessary, replace the main cylinder
3. Rubber gasket damaged. Repair the caliper.
Poor braking despite high pedal pressure
1. Brake pads are oily. Replace brake pads.
2. Incorrect or hardened pads installed. Replace pads. Install original AUDI pads.
3. Brake booster defective. Check the brake booster.
4. Worn brake pads. Replace brake pads.
Vehicle pulls to one side when braking
1. The tire pressure is not correct. Check and correct tire pressure.
2. Uneven tire wear. Replace worn tires.
3. Brake pads are oily. Replace pads.
4. Different brake pads are installed on the same axle. Replace pads. Install original AUDI pads.
5. Bad condition of the brake pads. Replace pads.
6. The caliper shafts are dirty. Clean the guides and seating surfaces of the pads in the caliper.
7. Corrosion of brake caliper cylinders. Replace caliper.
8. Uneven brake pad wear. Replace brake pads (on both wheels).
Brake tightens by itself
1. The compensation hole in the main brake cylinder is clogged. Clean the master cylinder and replace the internals.
2. The gap between the drive rod and the master cylinder piston is too small. Check clearance.
Brakes get hot while driving
1. The compensation hole in the main brake cylinder is clogged. Clean the master cylinder and replace the internals.
2. The gap between the drive rod and the master cylinder piston is too small. Check clearance.
3. The throttling hole in the special valve on the bottom is clogged. Clean the main brake cylinder, replace the internal elements and brake fluid.
The brakes are shaking
1. Wrong pads installed. Replace pads, install original AUDI pads.
2. The brake disc is corroded in places. Carefully sand the brake disc.
3. The brake disc has lateral runout. Repair or replace the disk.
Brake pads do not move away from the brake disc, the wheel is difficult to turn by hand
Corrosion in brake caliper cylinders. Repair the caliper, possibly replace it.
Uneven pad wear
1. Incorrect pads installed. Replace pads, install original AUDI pads.
2. Caliper dirty. Clean out the caliper shaft.
3. Heavy piston stroke. Eliminate.
4. The brake system is leaking. Check the tightness of the brake system.
Wedge-shaped brake pad wear
1. The brake disc does not rotate parallel to the caliper. Check the contact surfaces of the caliper.
2. Corrosion in calipers. Eliminate contamination.
3. The piston is not working properly. Check piston position.
Screeching brakes
1. Often due to atmospheric influence (air humidity). If a creak appears after a long stay in high humidity and then disappears, nothing needs to be done.
2. Incorrect pads installed. Replace the pads, install original AUDI A3 pads, coat the base plates with anti-squeak paste.
3. The brake disc does not rotate parallel to the caliper. Check the contact surfaces of the brake caliper.
4. The caliper shaft is dirty. Clean the caliper shaft
5. Pad springs bent. Replace mounting springs.
6. Stretched compression springs. Replace compression springs.
Pulsation of the brake pedal
1. ABS in action. OK, no help needed.
2. Too much lateral runout or brake disc thickness tolerance. Check runout and thickness. Repair or replace the disc.
3. The brake disc does not rotate parallel to the caliper. Check the contact surface of the caliper.
The ABS warning light comes on while driving
1. Supply voltage too low (below 10 V). Check voltage. Check if the generator control lamp goes out after starting the engine. If everything is in order, check the alternator drive V-belt.
2. ABS damage. Check for good contact and corrosion at the ground connection on the return pump (in the hydraulic block).
Suspension and steering
Vehicle pulls to one side when moving
1. Tires unevenly inflated.
2. Tires are defective.
3. Excessively worn suspension or steering components
4. Front wheel alignment required.
5. Front brakes seized
There are jerks, jerks or vibrations
1. The wheels are out of balance or the discs are out of shape. Have the tire balanced at a tire shop.
2. Worn wheel bearings, loose torque or misadjustment
3. Worn or damaged shock absorbers or other suspension components
There is excessive rocking of the vehicle or "burying" his nose when cornering or braking
1. Shock absorbers faulty. Replace the whole set
2. Broken or weak springs and/or other suspension components. Check the status of the components
Steering wheel too tight
1. The fluid level in the reservoir of the power steering system has dropped excessively
2. Tires incorrectly inflated.
3. Insufficiently lubricated steering joints
4. The adjustment of the angles of installation of the front wheels is broken.
5. The hydraulic booster does not develop the required power
There is excessive steering play
1. Loose torque on front wheel bearings
2. Excessively worn suspension or steering components
The power steering system does not develop the proper force
1. Power steering pump drive belt worn or damaged or its tension adjusted incorrectly
2. Hydraulic fluid level too low
3. The patency of the hoses or lines of the hydraulic system is broken. Check and replace if necessary.
4. Air has entered the hydraulic system. Bleed the system
Excessive tread wear (not in one area)
1. Tires incorrectly inflated.
2. Wheel balance out of alignment. Contact a tire shop.
3. Damaged wheel rims. Check and replace if necessary.
4. Suspension or steering components are excessively worn.
Excessive tread wear on outer edge
1. Tires incorrectly inflated.
2. Too sharp turns. Reduce your speed.
3. Adjustment of angles of installation of forward wheels is broken (excessive convergence). Contact a workshop for professional adjustment.
4. Bent or twisted suspension arm.
Excessive tread wear on the inside edge
1. Tires incorrectly inflated.
2. Adjustment of angles of installation of forward wheels is broken (divergence). Carry out the adjustment at a car service workshop.
3. Steering components damaged or loose.
There is localized tread wear
1. Wheel balance out of alignment.
2. Damaged or bent discs. Check and replace if necessary.
3. Tires are defective.
Wiper blade defects
Slippage
1. The rubber bands are dirty. Clean the rubber bands with a stiff nylon brush and detergent solution or alcohol.
2. Frayed edges of the brushes, rubber bands worn or torn. Replace rubber bands.
3. Old rubber bands, cracked surfaces. Replace rubber bands.
In the cleaning field, the remaining water immediately collects in drops
The windshield is dirty with lacquer polish or oil. Clean the windshield with a clean cloth with grease, oil, silicone remover.
The brush cleans one-sidedly - one side is good, the other is not
1. The rubber is deformed in one direction "no longer tip over". Install new rubber.
2. The wiper arm is twisted, the blade does not fit exactly on the glass. Carefully turn the lever until the vertical position is reached.
Uncleaned surfaces
1. The rubber has come loose from the frame. Carefully insert the elastic into the frame.
2. The brush does not adhere to the glass evenly, as the spring bars or plates are bent. Replace brush. This malfunction first of all appears at careless installation of a spare brush.
3. Lever clamping force is too low. Lightly lubricate the wiper arm pivots and springs, or install a new arm.
Tire defects
Heavy tire wear on both sides of the running surface
Tire pressure too low.
Strong tire wear in the middle of the working surface, around the entire circumference
Too high tire pressure.
Uneven tread wear
Static and dynamic wheel imbalance. Perhaps too much lateral runout of the disc, too much play in the bearing joints.
Uneven wear in the middle of the tread
Static wheel imbalance. Possible consequence of a strong vertical beat.
Strong wear of individual places in the middle of the working surface
Traces of blocking at full braking.
Sawtooth tread wear. Often accompanied by a tear in the fabric base that is not visible from the outside
Vehicle overload. Check the inside of the tire for warp breaks.
Rubber tabs on the side edges of the tread
Incorrect wheel alignment. The tire is worn out. On the rear wheels, also check the condition of the shock absorber.
Burr formation on one side of the front wheel tread
Incorrect toe adjustment. The tire is worn out. Frequent movement on undulating surfaces. Fast cornering.
Cord breaks. At first visible only from the inside
Driving over sharp rocks, tire bumps, etc. at high speed.
One-sided worn work surface
1. Check camber adjustment.
2. ABS damage. Check the reliability of the contact of the connection with the body at the return pump (in the hydraulic block).
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