Extraneous noises and knocks in the engine
| List of possible malfunctions | Diagnostics | Methods of elimination |
| Valve clearances not adjusted | Check the gaps | Adjust the gaps |
| Settling or breakage of valve springs | Inspection during engine disassembly | Repair the engine |
| The timing belt is worn out. The drive tensioner or support roller is faulty | Inspection | Replace the belt. Replace faulty timing belt tensioner or support rollers |
| Wear of bearings and camshaft cams, connecting rod and main bearings of the crankshaft, pistons, piston pins, play or seizure in the bearings of the generator, coolant pumps and power steering | Examination | Repair or replacement of parts |
| One or more powertrain mounts have lost their elasticity or have been damaged | Inspection | Replace the support |
| Low oil pressure (at minimum crankshaft speed at idle, the pressure in the lubrication system of a warm engine should be at least 1.0 bar) | Check the pressure in the lubrication system. You can measure the pressure by connecting a pressure gauge to the oil line, unscrewing the oil pressure sensor | Troubleshoot the lubrication system |
| Wear of the oil pump drive chain | Checking the chain tension after removing the oil pan | Replace the oil pump drive chain |
Strong engine vibration
| List of possible malfunctions | Diagnostics | Methods of elimination |
| Uneven compression across cylinders over 2.0 bar: valve drive clearances not adjusted, valves or seats worn or damaged; wear, sticking or breakage of piston rings | We check the compression. Compression must be at least 11.0 bar | Adjust the valve clearances. Replace faulty parts |
| Damage to the insulation of high-voltage devices and circuits - interruptions in spark formation | Use an ohmmeter to check the ignition coil winding and high-voltage wires for breakage or "breakdown" | Replace faulty ignition coil, damaged high-voltage wires. Under severe operating conditions (salt on the roads, frosts alternating with thaws) it is advisable to replace the wires every 3-5 years |
| High voltage wires are connected to the ignition coil in the wrong order; one or more wires have become disconnected | Inspection | Connect the wires according to the markings on the ignition coil |
| Defective spark plugs: current leakage through cracks in the insulator or carbon deposits on the thermal cone, poor contact of the central electrode | Check the spark plugs | Replace defective spark plugs |
| Open or short circuit in the injector windings or their circuits | Check the injector windings and their circuits with an ohmmeter | Replace faulty injectors, ensure contact in electrical circuits |
| The injectors are leaky (overflow) or their sprayers are dirty | Check the tightness and spray pattern of the injectors | Contaminated injectors can be washed on a special stand. Replace leaky and heavily contaminated injectors |
| The power unit supports have lost their elasticity or have been destroyed, their fastening has become loose | Inspection | Replace the supports, tighten the fasteners |
Increased content of harmful substances in exhaust gases
| List of possible malfunctions | Diagnostics | Methods of elimination |
| The injectors are leaky (overflow) or their sprayers are dirty | Check the tightness and spray pattern of the injectors | Contaminated injectors can be washed on a special stand. Replace leaky and heavily contaminated injectors |
| Damage to the insulation of high-voltage devices and circuits - interruptions in spark formation | To check the high-voltage wires and ignition coil, replace them with known good ones | Replace faulty ignition coil, damaged high-voltage wires. In severe operating conditions (salt on the roads, frosts alternating with thaws) it is advisable to replace the wires every 3-5 years |
| Defective spark plugs: current leakage through cracks in the insulator or carbon deposits on the thermal cone, poor contact of the central electrode | Check the spark plugs | Replace defective spark plugs |
| The intake air temperature sensor or its circuits are faulty | Use a tester to check the sensor for proper operation | Restore contact in electrical circuits, replace faulty sensor |
| Coolant temperature sensor is faulty | Check the sensor resistance with an ohmmeter at different temperatures | Replace the faulty sensor |
| The throttle position sensor or its circuits are faulty | Check the throttle position sensor for proper operation | Restore contact in electrical circuits, replace faulty sensor |
| The oxygen concentration sensor or its circuits are faulty | The performance of the oxygen concentration sensor and the reliability of its electrical circuit connections can be assessed using diagnostic equipment | Repair damaged electrical circuits. Replace the faulty sensor |
| The absolute air pressure sensor and its circuits are faulty | You can check the serviceability of the absolute air pressure sensor using diagnostic equipment | Restore contacts in electrical circuits. Replace the faulty sensor |
| The ECU or its circuits are faulty | To check, replace the ECU with a known good one | Restore contacts in electrical circuits. Replace the faulty ECU |
| Leakage in the exhaust system between the exhaust manifold and the downpipe | Inspection at medium crankshaft speed | Replace the defective gasket, tighten the threaded connections |
| The catalytic converter of the exhaust gases is faulty | You can check the serviceability of the catalytic converter of exhaust gases using diagnostic equipment | Replace the catalytic converter |
| Increased pressure in the fuel system due to a faulty pressure regulator | Inspection, checking the pressure in the fuel system with a pressure gauge (no more than 3.5 bar) at idle | Replace the faulty regulator |
| Increased air flow resistance in the intake tract | Check the air filter element, intake tract (absence of foreign objects, leaves, etc.) | Clean the intake tract, replace the dirty air filter element |
| Large amounts of oil entering the engine combustion chambers due to wear or damage to valve stem seals, valve stems, valve guides, piston rings, pistons and cylinders | Inspection after engine disassembly | Repair the engine |
Coolant level in the expansion tank has dropped
| List of possible malfunctions | Diagnostics | Methods of elimination |
| Damage to the radiator, expansion tank, hoses, loosening of their fit on the pipes | Inspection. Tightness of radiators (engine and heater) tested in a water bath with compressed air under a pressure of 1 bar | Replace damaged parts |
| Coolant pump seal leaking fluid | Inspection | Replace the pump |
| The cylinder head gasket is damaged. Cylinder block or head defect | The oil level indicator shows an emulsion with a whitish tint. Heavy white smoke from the muffler and oil stains on the surface of the coolant may appear (in the expansion tank). Coolant leaks on the outer surface of the engine | Replace damaged parts. Do not use water in the cooling system, fill with coolant that is appropriate for the climatic conditions |
The car does not have sufficient responsiveness. Jerks and dips when moving
| List of possible malfunctions | Diagnostics | Methods of elimination |
| The air filter element is clogged | Check the condition of the air filter element | Blow out or replace the air filter element |
| Increased resistance to gas movement in the exhaust system | Inspect the exhaust system for dented or damaged pipes, check the condition of the catalytic converter (back pressure) (ONE HUNDRED) | Replace damaged exhaust system components |
| Suction of extraneous air into the intake tract | Inspect the joints, check the fit of the throttle assembly, absolute pressure and air temperature sensors. Disconnect the brake booster for a short time by plugging the intake manifold fitting | Replace gaskets, sealing rings, parts with deformed flanges, faulty vacuum booster |
| Incomplete throttle opening | Determined visually with the engine stopped | Adjust the throttle actuator |
| Low compression in engine cylinders (less than 11.0 bar): wear or damage to valves, their guide bushings and seats, sticking or breakage of piston rings | Check the compression | Replace faulty parts |
| The valve timing is out of order | Check the valve timing | Establish the correct relative position of the shafts. Check the compression |
| The gaps between the spark plug electrodes do not comply with the norm | Check the gaps | By bending the side electrode, set the required gap or replace the spark plugs |
| Heavy carbon deposits on spark plug electrodes; carbon particles getting into the gap between the electrodes | Inspection | Check and replace spark plugs if necessary |
| Damage to insulation of high-voltage devices and circuits | Use an ohmmeter to check for a break or "breakdown" (short circuit to ground) in the ignition coil winding, high-voltage wires | Replace damaged ignition coil, high-voltage wires |
| There is not enough fuel in the tank | According to the fuel level indicator and reserve indicator | Add fuel |
| The fuel filter is clogged, water that got into the fuel system has frozen, and the fuel lines are deformed | Check the fuel system pressure | Replace the fuel filter. In winter, place the car in a warm garage and blow out the fuel lines. Replace defective hoses and tubes |
| The fuel pump does not create the required pressure in the system | Check the pressure in the fuel system, make sure the mesh filter of the fuel module is clean | Clean the fuel module mesh filter. Faulty fuel pump, pressure regulator replace |
| Poor contact in the fuel pump power supply circuit (including ground wire) | Checked with an ohmmeter | Clean contacts, crimp wire ends, replace faulty wires |
| The injectors or their circuits are faulty | Check the injector windings and their circuits with an ohmmeter (no breaks or short circuits) | Replace faulty injectors, ensure contact in electrical circuits |
| The air temperature sensor or its circuits are faulty | Check the sensor and its circuits | Restore contact in electrical circuits, replace faulty sensor |
| The absolute air pressure sensor or its circuits are faulty | The performance of the absolute air pressure sensor can be assessed using diagnostic equipment at a service station | Restore contact in electrical circuits, replace faulty sensor |
| The oxygen concentration sensor is faulty | The performance of the oxygen concentration sensor and the reliability of its electrical circuit connections can be assessed using diagnostic equipment at a service station | Repair damaged electrical circuits. Replace the faulty sensor |
| The ECU or its circuits are faulty | To check the ECU, replace it with a known good one | Replace the faulty ECU |
| Valve clearances not adjusted | Check the valve clearances | Adjust the valve clearances |
| Severe wear of camshaft lobes | Inspection during engine disassembly at a service station | Replace the worn camshaft at a service station |
| Settling or breakage of valve springs | Inspection during engine disassembly | Repair the engine at a service station |
| The throttle position sensor or its circuits are faulty | Check the throttle position sensor | Restore contact in electrical circuits, replace faulty sensor |
| Coolant temperature sensor is faulty | Check the resistance of the sensor at different temperatures with a tester | Restore contact in electrical circuits, replace faulty sensor |
Popping noises in the intake manifold
| List of possible malfunctions | Diagnostics | Methods of elimination |
| Valve clearances not adjusted | Check the valve clearances | Adjust the valve clearances |
| Inlet valves stick in the guide bushings: resinous deposits on the surface of the valve stem or bushing, sediment or breakage of valve springs | Inspection during engine disassembly (service station) | Repair the engine (service station) |
| The valve timing is out of order | Check the valve timing | Establish the correct relative position of the crankshaft and camshaft. Check the compression |
Shots in the silencer
| List of possible malfunctions | Diagnostics | Methods of elimination |
| Valve clearances not adjusted | Check the valve clearances | Adjust the valve clearances |
| Exhaust valves stick in the bushings: increased wear of the valve stem or bushing, sediment or breakage of valve springs | Inspection during engine disassembly | Repair the engine at a service station |
| The valve timing is out of order | Check the valve timing | Establish the correct relative position of the shafts. Check the compression |
| Spark plugs are faulty: current leakage through cracks in the insulator or carbon deposits on the thermal cone, poor contact of the central electrode | The spark plugs are checked on a special stand (service station). The absence of external damage and sparking between the electrodes on the removed spark plug does not allow us to draw a conclusion about its operability | Replace the spark plugs |
| Damage to the insulation of high-voltage devices and circuits - interruptions in spark formation | Use an ohmmeter to check for a break or "breakdown" (short circuit to ground) in the ignition coil winding, high-voltage wires | Replace faulty ignition coil, damaged high-voltage wires (when disconnecting a wire, pull on its tip). In severe operating conditions, it is advisable to replace the wires every 3-5 years |
| The injectors are faulty | Check the operation of the injectors | Replace faulty injectors |
Increased oil consumption (more than 500 g per 1000 km)
| List of possible malfunctions | Diagnostics | Methods of elimination |
| Oil leak through: crankshaft and camshaft seals; oil pan gaskets, cylinder head; oil pressure sensor; oil filter sealing ring | Wash the engine, then after a short run inspect the possible leak areas | Tighten the fastening elements of the cylinder head, cylinder head cover, oil pan, replace worn seals and gaskets |
| Wear, loss of elasticity of oil-deflecting caps (valve seals). Wear of valve stems, guide bushings | Inspection of parts during engine disassembly | Replace worn parts |
| Wear, breakage or coking (loss of mobility) piston rings. Wear of pistons, cylinders | Inspection and measurement of parts after engine disassembly | Replace worn pistons and rings. Bore and hone the cylinders |
| Use of oil of inappropriate viscosity | - | Change the oil |
| The crankcase ventilation system is clogged | Inspection | Clean the ventilation system |
Increased fuel consumption
| List of possible malfunctions | Diagnostics | Methods of elimination |
| The air filter element is clogged | Check the condition of the air filter element | Blow out or replace the air filter element |
| Leakage in the power supply system | Smell of gasoline, fuel leaks | Check the tightness of the connections of the fuel system elements; if a fault is detected, replace the corresponding components |
| Spark plugs are faulty: current leakage through cracks in the insulator or carbon deposits on the thermal cone, poor contact of the central electrode | The spark plugs are checked on a special stand at the service station. The absence of external damage and sparking between the electrodes on the removed spark plug does not allow us to draw a conclusion about its operability | Replace the spark plugs |
| Throttle actuator malfunction | Check the gas pedal travel and the clearance in the drive (free pedal travel), make sure that the cable and pedal are not jammed | Replace faulty parts, lubricate the cable with engine oil |
| The idle speed control valve or its circuits are faulty | Replace the regulator with a known good one | Replace the faulty regulator |
| The throttle valve does not close completely | When held up to the light, a gap is visible between the throttle valve and the body walls | Replace the throttle assembly |
| Increased pressure in the fuel line due to a faulty pressure regulator | Check the fuel system pressure with a pressure gauge (no more than 3.5 bar) | Replace the faulty regulator |
| Leaky injectors | Check the injectors | Replace faulty injectors |
| The coolant temperature sensor or its circuits are faulty | Check the sensor resistance with an ohmmeter at different temperatures | Restore contact in electrical circuits, replace faulty sensor |
| The oxygen concentration sensor is faulty | The performance of the oxygen concentration sensor and the reliability of its electrical circuit connections can be assessed using diagnostic equipment at a service station | Restore damaged electrical circuits, replace faulty sensor |
| The ECU or its circuits are faulty | To check, replace the ECU with a known good one | Replace the faulty ECU, restore damaged electrical circuits |
| Low compression in engine cylinders (less than 11.0 bar): drive clearances not adjusted, valves, their guide bushings and seats worn or damaged, piston rings stuck or broken | Check the compression | Adjust the valve clearances. Replace faulty parts |
| The throttle position sensor, absolute pressure and intake manifold air temperature sensors or their circuits are faulty | Check the sensors and their circuits | Restore contact in electrical circuits, replace faulty sensor(s) |
| Increased resistance to gas movement in the exhaust system | Inspect the exhaust system for dented or damaged pipes, and check the condition of the catalytic converter | Replace damaged exhaust system components |
| Chassis and brake system faults | Check the chassis components and the brake system | Adjust wheel alignment, replace faulty chassis parts, troubleshoot brake system |
Engine detonation (high-pitched metallic knocking sounds that usually occur when the engine is running under load, especially at low revs, such as acceleration under tension, etc., and disappear when the load is reduced)
| List of possible malfunctions | Diagnostics | Methods of elimination |
| Unacceptably low octane number of gasoline | — | Fill your vehicle with fuel recommended by the manufacturer |
| Engine overheating | According to the coolant temperature gauge | Eliminate the cause of overheating (see "Engine overheats") |
| Lots of carbon deposits in combustion chambers, piston bottoms, valve plates | Inspection after removing the cylinder head | Eliminate the cause of carbon deposits (see "Increased fuel consumption", "Increased oil consumption"). Use oils of the recommended viscosity and, if possible, with low ash content |
| Spark plugs with the wrong heat rating are used | — | Use spark plugs recommended by the manufacturer |
Insufficient oil pressure (low oil pressure indicator is on)
| List of possible malfunctions | Diagnostics | Methods of elimination |
| Low oil in engine | According to the oil level indicator | Add oil |
| The oil filter is faulty | Replace the filter with a known good one | Replace the faulty oil filter |
| The tightening of the auxiliary drive pulley mounting bolt is loose | Check the bolt tightness | Tighten the bolt to the specified torque |
| Clogged oil receiver mesh | Inspection | Clean the mesh |
| Misalignment, clogging of the oil pump pressure relief valve or weakening of the valve spring | Inspection during disassembly of the oil pump | Clean or replace the faulty pressure relief valve. Replace the pump |
| Wear of oil pump gears | Determined by measuring the parts after disassembling the oil pump (at the service station) | Replace the oil pump |
| Excessive clearance between bearing shells and crankshaft journals | Determined by measuring the parts after disassembling the oil pump (at the service station) | Replace worn bearings. Replace or repair the crankshaft if necessary |
| Low oil pressure sensor is faulty | We unscrew the low oil pressure sensor from the hole in the cylinder head and install a known good sensor in its place. If the indicator goes out while the engine is running, the removed sensor is faulty | Replace a faulty low oil pressure sensor |
The engine gets very hot (engine overheating indicator is on)
| List of possible malfunctions | Diagnostics | Methods of elimination |
| Thermostat is faulty | Check the thermostat for proper operation | Replace the faulty thermostat |
| Insufficient amount of coolant | The fluid level is below the "MIN" mark on the expansion tank | Fix the leaks. Top up the coolant |
| Lots of scale in the cooling system | — | Flush the cooling system with a descaler. Do not use hard water in the cooling system. Dilute concentrated antifreeze only with distilled water |
| The radiator cells are dirty | Inspection | Rinse the radiator with a jet of water under pressure |
| The coolant pump is faulty | Remove the pump and inspect the unit | Replace the pump assembly |
| The cooling system fan does not turn on | Check the fan circuits | Restore contact in the electrical circuits. Faulty fuse, relay, cooling fan, temperature sensor, ECU - replace |
| Unacceptably low octane number of gasoline | — | Fill your vehicle with fuel recommended by the manufacturer |
| Lots of carbon deposits in combustion chambers, piston bottoms, valve plates | Inspection after removing the engine cylinder head | Eliminate the cause of carbon deposits (see "Increased fuel consumption", "Increased oil consumption"). Use oil of the recommended viscosity and, if possible, with low ash content |
| Exhaust gas leak into the cooling system through a damaged cylinder head gasket | There is a smell of exhaust gases in the expansion tank and bubbles are floating up | Replace the cylinder head gasket. Check the cylinder head for flatness |
The engine cooling fan is constantly running (even on a cold engine)
| List of possible malfunctions | Diagnostics | Methods of elimination |
| Open circuit in the coolant temperature sensor or its circuit | The sensor and circuits are checked with an ohmmeter | Restore contact in the electrical circuits. Replace the faulty sensor |
| The fan relay contacts do not open | Checking with a tester | Replace the faulty relay |
| The ECU or its circuits are faulty | Check the ECU or replace it with a known good one | Replace the faulty ECU |
The engine takes a long time to warm up to operating temperature
| List of possible malfunctions | Diagnostics | Methods of elimination |
| Thermostat is faulty | Check the thermostat for proper operation | Replace the faulty thermostat |
| Low air temperature (below -15°C) | - | Insulate the engine: cover the gap in the front bumper with windproof material |
The engine starts in other modes except "P" and "N"
| Possible causes of malfunction | Troubleshooting |
| The engine start permission sensor adjustment is broken | Adjust the position of the sensor (at the service center) |
| The engine management system is faulty | Diagnose the engine management system (at a service center), replace faulty components |
| The gear selector lever cable adjustment is out of adjustment | Adjust the drive (at the service center), replace the cable if necessary |
Jerks when shifting gears, the car does not move when switching to "D" or "R" modes
| Possible causes of malfunction | Troubleshooting |
| Low fluid level in the box | Check the fluid level using the indicator, add fluid if necessary |
| The gear selector lever position sensor is faulty | Diagnose the sensor (at the service center), replace the faulty sensor |
| The engine management system is faulty | Diagnose the engine management system (at a service center), replace faulty components |