Contents: 1. Difficulty starting the engine ↧ 2. Unstable engine operation ↧ 3. Reduced vehicle dynamics ↧ 4. Deterioration of the vehicle's… ↧ 5. Increased fuel consumption ↧
1. Difficulty starting the engine
Difficulty starting a cold engine (the engine management system malfunction indicator light may come on)
1. The battery is discharged or the electrolyte level is insufficient. Check the battery condition, charge it, replace the faulty one. After connecting the terminals, cover them and the battery terminals with a special compound or any plastic lubricant.
2. The fuel supply system components are faulty. Check the pressure in the fuel supply system and replace faulty parts.
3. The engine management system coolant temperature sensor is faulty. Perform diagnostics of the engine management system. Check the coolant temperature sensor, replace if faulty.
4. The engine management system is faulty. Perform diagnostics of the engine management system. Replace faulty elements.
Difficulty starting a hot engine (the engine management system malfunction indicator light may come on)
1. The air filter is clogged. Replace the air filter element.
2. The fuel supply system components are faulty. Check the pressure in the fuel supply system and replace faulty parts.
3. The engine management system coolant temperature sensor is faulty. Perform diagnostics of the engine management system. Check the coolant temperature sensor, replace if faulty.
4. The engine management system is faulty. Perform diagnostics of the fuel injection system. Replace faulty elements.
2. Unstable engine operation
The engine crankshaft speed at idle speed sometimes decreases, sometimes increases (the engine management system malfunction indicator light may come on, see above)
1. Leaky inlet manifold. Check and replace intake manifold seals and faulty parts.
2. The forced crankcase ventilation system is faulty. Check emission control systems, replace faulty parts.
3. The absolute pressure sensor in the intake manifold is faulty. Perform diagnostics of the engine management system. Check the absolute pressure sensor in the intake manifold; replace the faulty one.
4. Insufficient pressure in the fuel rail. Check the pressure in the fuel supply system, pinch off faulty parts.
5. Wear of the timing belt and/or belt tension roller. Check the technical condition of the engine and replace faulty parts.
Misfires (engine misfires) at idle and/or under load (the engine management system malfunction indicator light may come on, see above)
1. The spark plugs are faulty. Replace spark plugs.
2. Leaky inlet manifold. Replace intake manifold seals and faulty components.
3. The fuel filter is clogged. Replace the fuel filter.
4. The fuel injectors are faulty. Check and replace faulty fuel injectors.
5. Insufficient compression in the engine cylinders. Check the technical condition of the engine. Repair the engine by replacing worn and faulty parts.
6. The ignition module is faulty. Perform diagnostics of the engine management system. Check and replace the faulty part.
3. Reduced vehicle dynamics
The engine does not develop power (the engine management system malfunction indicator light may come on, see above)
1. The quality of gasoline or its octane number is lower than required. Drain the gasoline from the tank and fill the car with high-quality fuel. You can try to increase the octane number of gasoline with a special additive.
2. The air filter is clogged. Replace the air filter element.
3. The throttle assembly or gas pedal position sensor is faulty. To determine the malfunction, perform diagnostics of the engine management system. Check and, if necessary, replace the throttle assembly and gas pedal position sensor.
4. The absolute pressure and temperature sensor in the intake manifold is faulty. Perform diagnostics of the engine management system. Check and, if necessary, replace the absolute pressure sensor in the intake manifold.
5. The fuel filter is clogged. Replace the fuel filter.
6. The engine management system is faulty. To determine the malfunction, perform diagnostics of the engine management system. Replace faulty elements.
7. Sticking of the brake mechanism working cylinders. Check the technical condition of the brake system, replace faulty parts.
8. Insufficient compression in the engine cylinders. Check the technical condition of the engine. Repair the engine by replacing worn and faulty parts. You can temporarily try to increase compression using special additives to motor oil.
9. The exhaust system is faulty. Check the technical condition of the system and replace faulty parts.
10. Leakage (burnout) of the valves of the gas distribution mechanism. Remove the cylinder head and check the valves for leaks. Grind the valves. Replace faulty valves or cylinder head.
In a car with a manual transmission, the clutch slips (the engine speed increases, but the car does not accelerate)
1. Oil getting onto the working surfaces of the clutch working disc. Inspect the clutch housing. If there are oil leaks, remove the clutch and check the crankshaft and gearbox seals. Replace faulty parts and oily clutch drive disc (or replace the clutch assembly). Remove oil leaks, degrease the working surfaces of the clutch discs and flywheel.
2. Severe wear, warping or burning of the clutch driven disc linings. Replace the clutch slave disc or clutch assembly.
3. The clutch slips. Check the technical condition of the clutch. Remove the clutch and check the wear of the parts. Replace defective parts.
In a vehicle with an automatic transmission, gears are not shifted in a timely manner or a gear is engaged that is not appropriate for the vehicle speed.
1. The automatic transmission control system is faulty. Using special diagnostic equipment, connect it to the diagnostic connector to determine the fault codes of the automatic transmission. Eliminate the detected malfunction.
2. The automatic transmission is faulty. Using special diagnostic equipment, connect it to the diagnostic connector to determine the fault codes of the automatic transmission. Eliminate the detected malfunction.
4. Deterioration of the vehicle's directional stability
Vehicle deviation from straight-line motion (on a straight section of road without a slope)
1. Different tire pressure on the front wheels. Check and adjust tire pressure to normal.
2. Different degrees of wear on the front tires. Check the condition of the tires. Replace worn tires. If necessary, rearrange the wheels so that the same axle has tires with the same degree of wear (for vehicles without a tire pressure monitoring system and with a non-directional tread pattern).
3. Different stiffness or breakage of one of the front suspension springs. Check the technical condition of the front suspension. Replace faulty springs.
4. Different stiffness or breakage of one of the rear suspension springs. Check the technical condition of the rear suspension, replace the springs as a set.
5. Wheel alignment is out of adjustment. Have your wheel alignment checked and adjusted at a specialist workshop.
6. Braking of one of the car's wheels. Check the technical condition of the brake system. Replace defective parts.
Vehicle drifts away from straight-line motion when braking
1. Different tire pressure on the front wheels. Check the tire pressure and, if necessary, bring the pressure up to normal.
2. One of the brake mechanisms is faulty. Check the technical condition of the brake system. Replace defective parts.
3. The hose or line of one of the brake mechanisms is pinched. Check the technical condition of the brake system. Replace defective parts.
4. Different degrees of wear of the brake mechanism parts of one of the vehicle axles. Check the technical condition of the brake system. Replace unevenly worn brake discs and brake pads.
5. The anti-lock braking system (ABS) is faulty. Determine the system status by reading the ABS fault codes using special diagnostic equipment. Eliminate the detected malfunction.
6. The vehicle is overloaded or loaded unevenly. When transporting cargo, do not exceed the permissible axle load of the vehicle, as indicated on the identification plate (see "Identification number"). Distribute the load evenly.
Deterioration of vehicle controllability
1. The steering rod joints are worn out. Check the technical condition of the steering. Replace faulty and worn parts.
2. The steering shaft joints are worn out. Check the technical condition of the steering. Replace faulty and worn parts.
3. The front wheel hub bearings are worn out. Check the technical condition of the wheel hubs. Replace faulty parts.
4. Play in the steering mechanism. Check the technical condition of the steering. Replace faulty and worn parts.
5. The front suspension shock absorbers are faulty. Check the condition of the front suspension. Remove and disassemble the front suspension struts, replace the shock absorbers as a set.
6. The rear suspension shock absorbers are faulty. Check the condition of the rear axle. Replace faulty shock absorbers as a set.
7. The stability control system, if present, is faulty. Determine the system status based on fault codes by connecting special diagnostic equipment to the diagnostic connector. Eliminate the detected malfunction.
8. The power steering drive is faulty. Determine the system status based on fault codes using special diagnostic equipment by connecting it to the diagnostic connector. Eliminate the detected steering malfunction.
5. Increased fuel consumption
1. Insufficient air pressure in the tires. Bring the tire pressure to normal.
2. The air filter is clogged. Replace the air filter element.
3. The exhaust gas oxygen concentration sensor is faulty. Perform diagnostics of the engine management system. Check and replace the oxygen concentration sensor if necessary.
4. The engine management system is faulty. Perform diagnostics of the engine management system. Replace faulty parts if necessary.
5. The fuel injectors are faulty. Perform diagnostics of the engine management system. Check and, if necessary, replace faulty injectors.
6. The fuel injectors are clogged. Clean the injectors using special fuel additives or using special equipment at a specialized service station.
7. The spark plugs are faulty. Check the condition of the spark plugs. Replace spark plugs.