The crankshaft does not rotate with the starter
List of possible malfunctions | Diagnostics | Elimination Methods |
The battery is empty | The voltage at the battery terminals with the consumers turned off is below 12 V. When the starter is turned on, a crackling noise may be heard from under the hood | Charge the battery; if it doesn't charge, replace it. The engine can be started «lit a cigarette» from the battery of another car |
Decreased battery capacity | The voltage at the battery terminals with the consumers turned off is more than 12 V, but when the starter is turned on, it drops below 6-8 V. At the same time, crackling may be heard from under the hood | Charge the battery with low current (no more than 1 A); if the capacity is still insufficient, replace the battery. The engine can be started «lit a cigarette» from the battery of another car |
Oxidation of the battery terminals and wire terminals, loose fit | When the starter is turned on, the voltage in the on-board network drops much more than at the battery terminals. There may be a crackling noise coming from under the hood | Tighten the terminals, clean the contact surfaces, lubricate them with technical vaseline |
Jamming of the engine or attachments | Check if the engine crankshaft, power steering pump pulleys, alternator and air conditioner compressor pulleys rotate | Repair engine, alternator, replace power steering pump, A/C compressor |
Damaged starter drive gear or flywheel teeth | Inspection after removing the starter | Repair or replace starter, replace flywheel |
Faulty starter enable circuit: faulty fuse EF3, damaged wires, ignition switch contacts do not close | When the ignition key is turned to position «START» starter relay does not work (no click under the hood). Check if +12 V is supplied to the control contact of the traction relay | Replace faulty: EF3 fuse, wires, ignition switch contact group |
Faulty starter traction relay: short circuit or open in the retracting winding, sticking of the relay armature (anchor misalignment, surface contamination, corrosion, etc.) | When the key is turned to position «START» traction relay does not work (no click under the hood), but +12 V is applied to the control contact of the traction relay. Remove the relay, check its operation | Replace faulty traction relay |
The contacts of the traction relay or wires are oxidized, poor contact «masses» | When the starter is turned on, a click is heard under the hood, but the starter armature does not rotate. Check circuit resistance with an ohmmeter «battery - starter», including wire «masses». If the circuits are good, remove the starter and check the operation of the traction relay by supplying power to it directly from the battery | Tighten the wire ends, crimp the terminals. Replace defective traction relay |
Breakage or short circuit in the holding winding of the traction relay of a starter | When the starter is turned on, a crack is heard from under the hood. Battery voltage is within normal limits. An open or short in the holding winding of the starter traction relay is checked with an ohmmeter or by excessive heating of the relay | Replace starter relay |
Burning of the starter collector, hanging brushes or their strong wear | Starter armature does not rotate or rotates slowly. First make sure that the traction relay is working, for which you can supply power to the starter contact bolt directly from the battery, bypassing the relay | Replace worn components or starter |
Open or short circuit in the winding of the starter armature | Starter armature does not rotate or rotates slowly. First make sure that the traction relay is working, for which you can supply power to the starter contact bolt, bypassing the relay. The health of the winding is checked with an ohmmeter or by darkening of the insulation | Replace anchor or starter |
Freewheel slippage | When the starter is turned on, the armature rotates, the flywheel is stationary | Replace clutch or starter |
Loud noise during starter operation
List of possible malfunctions | Diagnostics | Elimination Methods |
The starter is skewed to the cylinder block, its fastening is loose or the cover on the drive side is broken | Inspection | Tighten the bolts securing the starter to the cylinder block, if the cover breaks, replace the starter |
Excessive wear on starter bearings or drive shaft and armature journals. Wear and damage to the gear teeth of the planetary gearbox | Inspection after disassembling the starter | Replace planetary gear or starter |
The ring gear rotates on the flywheel | When the starter is turned on, the ring gear rotates, the flywheel and crankshaft are stationary. Squealing, howling from the clutch housing is heard | Replace flywheel |
Worn starter drive gear teeth or (more often) flywheel ring | Inspection after removing the starter | Replace drive gear, starter or flywheel |
The gear does not disengage from the flywheel: sticking of the drive lever, weakening or breakage of the spring of the freewheel clutch or starter traction relay, jamming of the clutch on the splines of the drive shaft or the armature of the traction relay, malfunction of the ignition switch (ignition switch contacts not opening) | Check if the voltage is removed from the control output of the starter relay when the ignition key is released, if the key returns to the position «ON». The opening of the ignition switch contacts can be checked with an ohmmeter. If the voltage at the starter traction relay disappears when the ignition is turned off, remove and disassemble the starter to check | Replace the starter traction relay or the starter assembly, the contact group of the ignition switch |
The crankshaft is turned by a starter, but the engine is not started up
List of possible malfunctions | Diagnostics | Elimination Methods |
There is no fuel in the tank | By fuel gauge and fuel reserve indicator | Top up fuel |
The battery is empty | The crankshaft is turned by a starter very slowly. The voltage at the terminals of the battery when the consumers are off is below 12 V | Charge the battery; if it does not charge, replace it. The engine can be started «lit a cigarette» from the battery of another car |
Decreased battery capacity | The crankshaft rotates very slowly. The voltage at the battery terminals when consumers are off is more than 12 V, but when the starter is turned on, it drops to 6-8 V | Charge the battery with low current (no more than 1 A); if the capacity is still insufficient, replace. The engine can be started «lit a cigarette» from the battery of another car |
Oxidation of the wire terminals at the battery terminals, loose fit | The crankshaft is turned by a starter very slowly. When the starter is turned on, the voltage in the on-board network drops much more than at the battery terminals | Tighten the terminals, clean the contact surfaces, lubricate them with technical vaseline |
Unreliable connection of electrical circuits of engine control and power systems | Check the connection of the electrical connectors of the wiring harnesses, the reliability of the contacts in the blocks of the wire lugs | Troubleshoot connections in connectors |
Increased resistance to rotation of the engine crankshaft: seizures on the shafts, bearing shells, parts of the cylinder-piston group; shaft deformation; frozen engine oil; jammed alternator, power steering pump, air conditioning compressor | The crankshaft is turned by a starter very slowly If the weather is cold, and the day before the engine was running steadily and without extraneous noise, the most likely cause of increased resistance to rotation is frozen oil. In this case, try starting the engine with a different battery. After starting, do not allow the engine to run at high speeds and watch the low oil pressure indicator: if it lights up, immediately stop the engine for 1-2 minutes so that the thickened oil has time to drain into the sump If extraneous noises are heard when starting or running the engine, check the free rotation of the pulleys of the power steering pump, generator and air conditioning compressor | If there is extraneous noise in the area of the block or cylinder head, repair the engine Use engine oil according to climatic conditions Replace alternator, power steering pump, A/C compressor |
Malfunction in the ignition system | Check spark plugs. If there is no spark, the cause may be malfunctions of devices and low voltage circuits (fuse F15, computer, ignition coil primary) or high voltage (secondary winding of the ignition coil, high-voltage wires) | Check ignition circuits and instruments. Replace defective fuse, instrument and wires. Ensure contact in electrical circuits |
Broken timing belt or sheared teeth | Inspection after removing the front upper timing cover | Replace timing belt. Check cylinder compression |
Defective candles | Check spark plugs | Replace spark plugs |
Valve timing broken | Check the alignment of the marks on the crankshaft and camshaft pulleys | Set the correct relative position of the shafts. Check compression |
Faulty computer, its circuits or crankshaft position sensor (less often - coolant temperature sensors and air temperature sensor) | Check if +12 V is being supplied to the ECU, crankshaft position sensor circuit, the sensor itself is not damaged. With a faulty temperature sensor, the ECU may incorrectly calculate the composition of the fuel mixture | Replace faulty F5 DC power fuse, ECU, sensors, wires |
Faulty absolute air pressure sensor or its circuit | Check the sensitivity of the absolute air pressure sensor | Replace defective absolute air pressure sensor |
Blown fuse EF2 | Check fuse | Eliminate the cause of the blown fuse. Replace defective fuse |
The fuse of the power circuit of the fuel pump relay F17 has blown, the pump power circuit, its relay or the pump itself are faulty | When the ignition is turned on, the sound of the pump is not heard. Check fuse. Apply power directly from the battery to the pump terminals | Replace blown fuse, clean contacts, crimp wire lugs, replace faulty relay, pump |
Clogged fuel filter, frozen water that got into the power system, deformed fuel lines | When cranking the crankshaft with a starter, there is no smell of gasoline from the exhaust pipe | Replace fuel filter. In winter, put the car in a warm garage, blow out the fuel lines |
The fuel pump does not create the necessary pressure in the system | Check fuel rail pressure, make sure fuel module strainer is clean | Clean the fuel module strainer. Faulty fuel pump, pressure regulator replace |
Faulty injectors or their power supply circuits | Check the injector windings and electrical circuits with an ohmmeter (no break and short circuit) | Replace faulty injectors, ensure contact in electrical circuits |
Intake of foreign air into the intake tract | Inspect the joints, check the fit of the hoses, fittings, tightness of the clamps. At the time of starting, turn off the vacuum brake booster and plug the intake manifold fitting | Replace torn gaskets, parts with deformed flanges, faulty vacuum booster |
Engine runs erratically or stalls at idle
List of possible faults | Diagnostics | Elimination Methods |
Unreliable connection of electrical circuits of engine control and power systems | Check the connection of the electrical connectors of the wiring harnesses, the reliability of the contacts in the blocks of the wire lugs | Troubleshoot connections in connectors |
The gap between the electrodes of the candles does not correspond to the norm | A gap of 0.7-0.8 mm is checked with a round probe | Adjust gap or replace spark plugs |
A lot of carbon deposits on the electrodes of the spark plugs; ingress of soot particles into the gap between the electrodes | Inspection | Check and replace spark plugs if necessary |
Faulty spark plugs: current leakage through cracks in the insulator or carbon deposits on the thermal cone, poor contact in the center electrode | The absence of external damage and sparking between the electrodes on an inverted candle does not allow us to conclude that it is working | Replace spark plugs |
Damage to the insulation of high-voltage devices and circuits | Check for continuity with an ohmmeter or «breakdown» (short circuit «mass») ignition coil windings and high voltage wires | Replace damaged ignition coil and high voltage wires |
Valve timing broken | Check the alignment of the marks on the crankshaft and camshaft pulleys | Set the correct relative position of the shafts. Check compression |
Low compression in the engine cylinders (less than 11 bar): wear or damage to valves, valve guides and seats, stuck or broken piston rings | Check compression | Replace defective parts |
Faulty throttle position sensor | Check Throttle Position Sensor | Replace defective sensor |
Faulty idle speed controller or its circuits | Substitute a known-good regulator | Replace failed regulator |
Intake of foreign air into the intake tract | Inspect the joints, check the fit of the hoses, fittings, tightness of the clamps. At the time of starting, turn off the vacuum brake booster by plugging the intake manifold fitting | Replace torn gaskets, parts with deformed flanges, faulty vacuum booster |
Faulty fuel pressure regulator | Check the pressure in the fuel system with a pressure gauge (2.8-3.3 bar) | Replace failed regulator |
The adsorber is faulty, leaks in the connections of the tubes of the fuel vapor recovery system | Check the adsorber for damage, serviceability of the purge solenoid valve and tightness of their connections | Replace defective adsorber, purge valve and tubing. Eliminate leaky connections |
Throttle valve or actuator stuck. Under these conditions, the ECU does not regulate the engine idling | Check the ease of movement of the damper | Adjust drive, throttle position. Replace Throttle Assembly |
Faulty injectors (open circuit, winding short circuit, atomizers are dirty) | Check the operation of the injectors | Replace faulty injectors. Wash dirty nozzles |
Camshaft lobes wear | Inspection after partial disassembly of the engine | Replace camshaft |
Faulty hydraulic lifters in the valve drive | Check compression | Replace faulty hydraulic lifters |
Faulty vehicle speed sensor | After stopping the car, the engine runs unevenly, but soon the idle speed stabilizes | Replace vehicle speed sensor |
The engine does not develop full power, the car does not have sufficient throttle response. Jerks and dips when driving a car
List of possible faults | Diagnostics | Elimination Methods |
Clogged air filter element | Check the condition of the air filter element | Blow out or replace the air filter element |
Increased resistance to the movement of gases in the exhaust system | Inspect the exhaust system for dented and damaged pipes, check the condition of the catalytic converter | Replace damaged exhaust system components |
Intake of foreign air into the intake tract | Inspect the joints, check the fit of the hoses, fittings, tightness of the clamps. Disconnect the brake booster for a short time by plugging the intake manifold fitting. (Carefully! The effort on the brake pedal will increase significantly!) | Replace gaskets, parts with deformed flanges, defective vacuum booster |
Incomplete throttle opening | Determined visually on a stopped engine | Adjust throttle actuator |
Valve timing broken | Check the alignment of the marks on the crankshaft and camshaft pulleys | Set the correct relative position of the shafts. Check compression |
Low compression in the engine cylinders (less than 11 bar): wear or damage to valves, valve guides and seats, stuck or broken piston rings | Check compression | Replace defective parts |
The gaps between the electrodes of the candles do not correspond to the norm | Check clearances | By bending the side electrode, set the desired gap or replace the candles |
Strong soot on the electrodes of the spark plugs; ingress of soot particles into the gap between the electrodes | Inspection | Check and replace spark plugs if necessary |
Damage to the insulation of high-voltage devices and circuits | Check for continuity with an ohmmeter or «breakdown» (short circuit «mass») ignition coil windings and high voltage wires | Replace damaged ignition coil and high voltage wires |
There is not enough fuel in the tank | According to the level indicator and fuel reserve indicator | Top up fuel |
Clogged fuel filter, frozen water that got into the power system, deformed fuel lines | Check the pressure in the fuel system (2.83.3 bar) | Replace fuel filter. In winter, put the car in a warm garage, blow out the fuel lines. Replace defective hoses and tubes |
The fuel pump does not create the necessary pressure in the system | Check fuel rail pressure (2.83.3 bar), make sure the fuel module strainer is clean | Clean the fuel module strainer. Faulty fuel pump, pressure regulator replace |
Poor contact in the fuel pump power circuit (including wires «masses») or its relay is faulty | Checked with an ohmmeter | Strip the contacts, crimp the wire lugs, replace the faulty relay, wires |
Faulty injectors or their circuits | The CHECK indicator lights up. Check the injector windings and their circuits with an ohmmeter (no break and short circuit) | Replace faulty injectors, ensure contact in electrical circuits |
Faulty generator | Check generator output voltage | Replace voltage regulator, repair or replace alternator |
The exhaust gas recirculation valve is defective | Check valve operation | Replace recirculation valve |
Faulty absolute air pressure sensor or its circuit | Check the sensitivity of the absolute air pressure sensor | Restore contact in electrical circuits, replace the faulty sensor |
One or both oxygen concentration sensors or their circuits are faulty | The CHECK indicator lights up. You can evaluate the performance of oxygen concentration sensors and the reliability of the connections of their electrical circuits using diagnostic equipment | Repair damaged electrical circuits. Replace defective sensor |
Faulty computer or its circuits | The CHECK indicator may be on. To check the ECU, replace it with a known good one | Replace faulty ECU |
Faulty hydraulic lifters in the valve drive | Check compression | Replace faulty hydraulic lifters |
Strong wear of the camshaft cams | Inspection after partial disassembly of the engine | Replace worn camshaft |
Sediment or broken valve springs | Inspection during engine disassembly | Repair the engine |
Faulty throttle position sensor or circuit | The CHECK indicator lights up. Check Throttle Position Sensor | Restore contact in electrical circuits, replace the faulty sensor |
Faulty coolant temperature sensor or air temperature sensor or circuits | Check the resistance of the sensor with a tester at different temperatures | Restore contact in electrical circuits, replace the faulty sensor |
Pops in the intake manifold
List of possible malfunctions | Diagnostics | Elimination Methods |
Faulty hydraulic lifters in the valve drive | Check compression | Replace faulty hydraulic lifters |
Inlet valves sticking in the guide bushings: gum deposits on the surface of the valve stem or bushing, sediment or broken valve springs | Inspection during engine disassembly | Repair the engine |
Valve timing broken | Check the alignment of the marks on the crankshaft and camshaft pulleys | Set the correct relative position of the crankshaft and camshaft. Check compression |
Shots in the silencer
List of possible malfunctions | Diagnostics | Elimination Methods |
Faulty hydraulic lifters in the valve drive | Check compression | Replace faulty hydraulic lifters |
Exhaust valves sticking in bushings: increased wear of the valve stem or bushing, sediment or broken valve springs | Inspection during engine disassembly | Repair the engine |
Valve timing broken | Check the alignment of the marks on the crankshaft and camshaft pulleys | Set the correct relative position of the shafts. Check compression |
Faulty spark plugs: current leakage through cracks in the insulator or carbon deposits on the thermal cone, poor contact of the central electrode | Candles are checked on a special stand. The absence of external damage and sparking between the electrodes on an inverted candle does not allow us to conclude that it is working | Replace spark plugs |
Damage to the insulation of high-voltage devices and circuits - interruptions in sparking | Check for continuity with an ohmmeter or «breakdown» (short circuit «mass») ignition coil windings and high voltage wires | Replace faulty ignition coil and high voltage wires |
Clogged air filter element | Check the condition of the air filter element | Blow out or replace the air filter element |
Increased fuel consumption
List of possible malfunctions | Diagnostics | Elimination Methods |
Leakage of the power system | Gasoline smell, fuel leaks | Tighten the fuel line connections. Check fit of fittings; if the fit is loose, replace the relevant components |
Faulty spark plugs: current leakage through cracks in the insulator or carbon deposits on the thermal cone, poor contact of the central electrode | Candles are checked on a special stand. The absence of external damage and sparking between the electrodes on an inverted candle does not allow us to conclude that it is working | Replace spark plugs |
Throttle Actuator Malfunction | Check pedal travel «gas», gap in the drive (pedal free play), check that there is no binding on the cable and pedal | Replace defective parts, lubricate the cable with engine oil |
Faulty idle speed controller or its circuits | Substitute a known-good regulator | Replace failed regulator |
Throttle not fully closing | The gap between the throttle valve and the walls of the throttle assembly housing is visible through the light | Replace Throttle Assembly |
Increased pressure in the fuel line due to a malfunction of the pressure regulator | Check the pressure in the fuel system with a pressure gauge (2.8-3.3 bar) | Replace faulty fuel pressure regulator |
Nozzle leakage | Check injectors | Replace faulty injectors |
Faulty coolant or air temperature sensors or their circuits | The CHECK indicator lights up. Check the resistance of the sensor with an ohmmeter at different temperatures | Restore contact in electrical circuits, replace the faulty sensor |
Faulty one or both oxygen concentration sensors | The CHECK indicator lights up. You can evaluate the performance of oxygen concentration sensors and the reliability of the connections of their electrical circuits using diagnostic equipment | Repair damaged electrical circuits, replace the faulty sensor |
Faulty computer or its circuits | Substitute a known-good ECU to test | Replace faulty ECU, repair damaged electrical circuits |
Low compression in the engine cylinders (less than 11 bar): faulty hydraulic compensators in the valve drive, wear or damage to valves, their guide bushings and seats, occurrence or breakage of piston rings | Check compression | Replace defective parts |
Faulty: throttle position sensor, absolute air pressure sensor or their circuits | The CHECK indicator lights up. Check sensors and their circuits | Restore contact in electrical circuits, replace the faulty sensor (sensors) |
Increased resistance to the movement of gases in the exhaust system | Inspect the exhaust system for dented and damaged pipes, check the condition of the catalytic converter | Replace damaged exhaust system components |
Increased oil consumption (more than 500 g per 1000 kilometers)
List of possible malfunctions | Diagnostics | Elimination Methods |
Oil leakage through: crankshaft and camshaft seals; gaskets for the oil pan, cylinder head, oil pump housing; low oil pressure sensor; oil filter sealing ring | Wash the engine, then after a short run inspect for possible leaks | Tighten the fastening elements of the cylinder head, oil pump, oil pan, replace worn oil seals and gaskets, low oil pressure sensor |
Wear, loss of elasticity of oil seals (valve seals). Wear of valve stems, guide bushings | Parts Inspection | 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. Boring and honing cylinders |
Use of oil of the wrong viscosity | — | Change oil |
Clogged crankcase ventilation system | Inspection | Clean the ventilation system |
Detonation
(high-pitched metallic knocks that occur, as a rule, when the engine is running under load, especially at low speeds, for example, acceleration «tightness» etc., and disappearing when the load is reduced)
List of possible malfunctions | Diagnostics | Elimination Methods |
Unacceptably low octane number of gasoline | — | Fill your car with fuel recommended by the manufacturer |
Engine overheating | According to the coolant temperature gauge | Eliminate the cause of overheating (see below «The engine gets very hot») |
A lot of carbon deposits in the combustion chamber, on the bottoms of the pistons, valve plates | Inspection after removal of the cylinder head | Eliminate the cause of soot formation (see «Increased fuel consumption», «Increased oil consumption»). Use oils of the recommended viscosity and, if possible, with a low ash content |
Candles with the wrong glow rating are used | — | Use spark plugs recommended by the manufacturer |
Insufficient oil pressure (low oil pressure warning light on)
List of possible malfunctions | Diagnostics | Elimination Methods |
Little oil in the engine | According to the oil level indicator | Add oil |
Use of oil of the wrong viscosity | — | Change oil |
Clogging of the oil receiver mesh | Inspection | clear the grid |
Defective oil filter | Substitute a filter with a known good one | Replace defective oil filter |
Misaligned, clogged oil pump relief valve or weakened valve spring | Inspection | Clean valve. Replace defective valve or pump |
Oil pump gear wear | Determined by measuring parts after disassembling the oil pump | Replace oil pump |
Excessive clearance between bearing shells and crankshaft journals | Determined by measuring parts after disassembling the engine | Replace worn liners. Replace or repair crankshaft if necessary |
Faulty low oil pressure sensor | We unscrew the low oil pressure sensor from the hole in the oil pump housing and install a known-good sensor instead. If the indicator goes out after starting, the inverted sensor is defective | Replace faulty low oil pressure sensor |
The engine gets very hot (the pointer is in the red sector of the scale)
List of possible malfunctions | Diagnostics | Elimination Methods |
Faulty coolant temperature sensor or gauge | Check the pointer and sensor with a tester | Faulty sensor, pointer - replace |
Faulty thermostat | Check the thermostat | Replace defective thermostat |
Insufficient amount of coolant | Liquid level below the mark «MIN» on the expansion tank | Eliminate leaks. Add coolant |
A lot of scale in the cooling system | Flush the cooling system with a descaling agent. Do not use hard water in the cooling system. Dilute concentrated antifreeze only with distilled water | |
Radiator cells dirty | Inspection | Flush the radiator with a high pressure water jet |
Faulty coolant pump | Remove the pump and inspect the assembly | Replace pump assembly |
Cooling fan does not turn on | Check fan circuits | Restore contact in electrical circuits. Faulty fuse, relay, motor, temperature sensor, ECU - replace |
Unacceptably low octane number of gasoline | — | Fill your car with fuel recommended by the manufacturer |
A lot of carbon deposits in the combustion chamber, on the bottoms of the pistons, valve plates | Inspection after removing the engine cylinder head | Eliminate the cause of soot formation (see «Increased fuel consumption», «Increased oil consumption»). Use an oil of the recommended viscosity and, if possible, with a low ash content |
Breakthrough of exhaust gases into the cooling system through a damaged cylinder head gasket | The expansion tank smells of exhaust gases and bubbles pop up | Replace the cylinder head gasket. Check for flatness of the cylinder head |
Engine cooling fan constantly running (even on a cold engine)
List of possible malfunctions | Diagnostics | Elimination Methods |
An open in the coolant temperature sensor or its circuit | The CHECK indicator lights up. The sensor and circuits are checked with an ohmmeter | Replace defective sensor |
Fan relay contacts not opening | Check by tester | Replace faulty relay |
Faulty computer or its circuits | Check the ECU or substitute with a known good one | Replace faulty ECU |
The engine takes a long time to warm up to operating temperature
List of possible malfunctions | Diagnostics | Elimination Methods |
Faulty thermostat | Check the thermostat | Replace defective thermostat |
Low air temperature (below -15°С) | — | Insulate the engine: install shields in front of the radiator, but do not cover more than half of its area |
Coolant level drop in expansion tank
List of possible malfunctions | Diagnostics | Elimination Methods |
Damage to radiators (engine and heater), expansion tank, hoses, weakening their fit on the nozzles | Inspection. Sealing of radiators (engine and heater) tested in a bath of water with compressed air at a pressure of 1 bar | Replace damaged parts |
Fluid leakage through the coolant pump seal | Inspection | Replace coolant pump |
Cylinder head gasket damaged. Block or cylinder head defect | The oil level indicator shows an emulsion with a whitish tint. There may be copious white smoke from the muffler and oil stains on the surface of the coolant (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 in coolant suitable for climatic conditions |
Extraneous noises and knocks in the engine
List of possible malfunctions | Diagnostics | Elimination Methods |
Faulty hydraulic lifters in the valve drive | Check hydraulic lifters | Replace faulty hydraulic lifters |
Sediment or broken valve springs | Inspection during engine disassembly | Repair the engine |
The timing belt is worn out. Faulty drive tensioner | Inspection | Replace belt. Replace the faulty camshaft pulley |
Knock crankshaft and camshaft, connecting rod and main bearings, pistons, piston pins, play or seizure in the bearings of the generator, coolant pump | Examination | Engine repair, coolant pump replacement, alternator repair or replacement |
Lost elasticity or collapsed one or more supports of the power unit | Inspection | Replace powertrain mount |
Low pressure in the oil line (at minimum idle speed, the pressure in the lubrication system of a warm engine must be at least 0.5 bar) | Check the pressure in the lubrication system. You can measure the pressure by connecting a pressure gauge to the oil line by unscrewing the oil pressure sensor | Troubleshoot the lubrication system |
Strong engine vibration
List of possible malfunctions | Diagnostics | Elimination Methods |
Uneven compression over the cylinders more than 2 bar: faulty hydraulic compensators in the valve drive, wear or damage to valves, seats; wear, sticking or breakage of piston rings | We check the compression. Compression must be at least 11 bar | Replace defective parts |
Damage to the insulation of high-voltage devices and circuits - interruptions in sparking | Check for continuity with an ohmmeter or «breakdown» ignition coil windings and high voltage wires | Replace faulty ignition coil and high voltage wires |
Defective spark plugs | Check spark plugs | Replace defective spark plugs |
The gap between the electrodes of the candles does not correspond to the norm | A gap of 0.7-0.8 mm is checked with a round probe | By bending the side electrode, set the desired gap or replace the candles |
Strong soot on the electrodes of the spark plugs; ingress of soot particles into the gap between the electrodes | Inspection. By soot, you can, as a rule, determine the performance of the candle and the condition of the engine | Clean spark plugs with compressed air or mechanically (do not damage the insulator!). Identify and eliminate the cause of increased carbon formation in the combustion chamber, replace the spark plugs if necessary |
Open or short circuit in the windings of the injectors or their circuits | Check the injector windings and their circuits with an ohmmeter | Replace faulty injectors, ensure contact in electrical circuits |
Leaky nozzles (overflow) or their nozzles are dirty | Check the tightness and shape of the nozzle spray pattern | Dirty nozzles can be washed on a special stand. Replace leaky or heavily soiled injectors |
The support of the power unit has lost elasticity or collapsed, their fastening has weakened | Inspection | Replace supports, tighten fasteners |
Increased content of harmful substances in exhaust gases
List of possible malfunctions | Diagnostics | Elimination Methods |
Leaky nozzles (overflow) or their nozzles are dirty | Check the tightness and shape of the nozzle spray pattern | Dirty nozzles can be washed on a special stand. Replace leaky or heavily soiled injectors |
Damage to the insulation of high-voltage devices and circuits - interruptions in sparking | To check the high-voltage wires and ignition coils, replace them with known good ones | Replace faulty ignition coil and high voltage wires |
Defective spark plugs: current leakage through cracks in the insulator or carbon deposits on the thermal cone, poor contact of the center electrode | Check candles | Replace defective spark plugs |
Faulty phase sensor or its circuits | The CHECK indicator lights up. Tester check the health of the phase sensor | Restore contact in electrical circuits, replace the faulty sensor |
Faulty coolant temperature sensor or air temperature sensor | Check the resistance of the sensor with an ohmmeter at various temperatures. | Replace defective sensor |
Faulty throttle position sensor or circuit | The CHECK indicator lights up. Check throttle position sensor | Restore contact in electrical circuits, replace the faulty sensor |
Faulty one or both oxygen concentration sensors | The CHECK indicator lights up. You can evaluate the performance of oxygen concentration sensors and the reliability of the connections of their electrical circuits using diagnostic equipment | Repair damaged electrical circuits. Faulty sensor (sensors) replace |
Faulty absolute air pressure sensor and its circuit | The CHECK indicator lights up. Check the sensitivity of the absolute air pressure sensor | Restore contacts in electrical circuits. Replace defective absolute air pressure sensor |
Faulty computer or its circuits | Substitute a known-good ECU to test | Restore contacts in electrical circuits. Replace faulty ECU |
Faulty catalytic converter | You can check the serviceability of the catalytic converter of exhaust gases using diagnostic equipment | Replace catalytic converter |
Increased pressure in the fuel rail due to a malfunctioning pressure regulator | Checking the pressure gauge in the fuel rail (2.8-3.3 bar) | Replace failed regulator |
Increased resistance to air flow in the intake tract | Check air cleaner element, intake tract (absence of foreign objects, leaves, etc.) | Clean the intake tract, replace the dirty air filter element |
The engine control system malfunction indicator lights up when the engine is running
List of possible malfunctions | Diagnostics | Elimination Methods |
Faulty computer, sensors, injectors or their circuits. The malfunction may be temporary, then the signaling device may turn off by itself, without any intervention | See previous topics «Troubleshooting». Full diagnostics of the control system is carried out using specialized equipment | When most sensors fail (except crankshaft position sensor) you can drive to the place of repair on your own. Replace faulty ECU, sensors, injectors, wires |
disconnected (maybe to check) separate sensors, injectors, after which the ignition was turned on (started the engine). At the same time, the corresponding fault code is recorded in the computer's memory, which is not erased even after the electrical connections are restored | — | Remove the terminal for at least 10 s «negative» wires from the battery terminal. In this case, all fault codes are erased from the computer memory |