Contents: When starting the engine, the…⬇ The crankshaft rotates, but the…⬇ Unstable cold engine starting: ⬇ Unstable hot engine starting: ⬇ When the starter is turned on, there…⬇ Stopping the engine after starting: ⬇ Unstable idling mode of the engine: ⬇ Misfires at idle: ⬇ Misfires throughout the entire…⬇ Engine vibration during acceleration: ⬇ Low engine power output: ⬇ Backfires in the engine: ⬇ Low engine oil pressure: ⬇ The engine runs after the ignition…⬇ Engine noises ⬇
When starting the engine, the crankshaft does not rotate:
- the battery terminals are not securely connected or are oxidized;
- the battery is discharged or faulty;
- damage to the wiring in the starter circuit;
- the starter traction relay is faulty;
- starter is faulty;
- the starter drive gear teeth or the flywheel ring gear teeth are worn out;
- the ground bus from the engine to the vehicle body is disconnected.
The crankshaft rotates, but the engine does not start:
- no fuel in tank;
- battery is low (the crankshaft rotates very slowly);
- the battery terminal is loose or oxidized;
- ignition system components are damaged (gasoline engines);
- incorrect spark plug gap (gasoline engines);
- the pre-heating system is faulty (diesel engines);
- fuel injection system damage (gasoline engines);
- the electromagnetic valve that shuts off the fuel supply is faulty (diesel engines);
- air in the fuel system (diesel engines);
- mechanical failure of the valve timing system.
Unstable cold engine starting:
- battery is low;
- the battery terminals are not securely connected or are oxidized;
- failure or incorrectly adjusted interelectrode gaps in spark plugs (gasoline engines);
- the pre-heating system is faulty (diesel engines);
- the fuel injection system is damaged (gasoline engines);
- ignition system damage (gasoline engines);
- low compression in cylinders.
Unstable hot engine starting:
- the air filter element is dirty;
- fuel injection system damage (gasoline engines);
- low compression in cylinders.
When the starter is turned on, there are extraneous noises:
- worn or broken teeth on the starter pinion or flywheel ring gear;
- starter mounting bolts are missing or not tightened securely;
- wear or damage to starter parts.
Stopping the engine after starting:
- unreliable connection of ignition system components (gasoline engines);
- air leak in the injection system or intake manifold (gasoline engines);
- fuel injection system damage (gasoline engines).
Unstable idling mode of the engine:
- the air filter element is dirty;
- air leak in the injection system, intake manifold or hoses (gasoline engines);
- the interelectrode gap is incorrectly adjusted or the spark plugs are worn out (gasoline engines);
- uneven or low compression in the cylinders;
- camshaft cams are worn out;
- the timing belt is not installed correctly;
- fuel injection system damage (gasoline engines);
- the injectors are faulty (diesel engines).
Misfires at idle:
- the interelectrode gap is incorrectly adjusted or the spark plugs are worn out (gasoline engines);
- defective high voltage wires (gasoline engines);
- air leak in the injection system, intake manifold or hoses (gasoline engines);
- fuel injection system damage (gasoline engines);
- the injectors are faulty (diesel engines);
- uneven or low compression in the cylinders;
- the engine crankcase ventilation hoses are disconnected or leaky.
Misfires throughout the entire engine speed range:
- the fuel filter is dirty;
- fuel pump faulty or low fuel pressure;
- the fuel tank drain hole or fuel lines are clogged;
- air leak in the injection system, intake manifold or hoses (gasoline engines);
- the interelectrode gap is incorrectly adjusted or the spark plugs are worn out (gasoline engines);
- the ignition coil is faulty (gasoline engines);
- the injector is faulty (diesel engines);
- distributor breaker cover is faulty (gasoline engines);
- uneven or low compression in the cylinders;
- fuel injection system damage (gasoline engines).
Engine vibration during acceleration:
- the interelectrode gap is incorrectly adjusted or the spark plugs are worn out (gasoline engines);
- air leak in the injection system, intake manifold or hoses (gasoline engines);
- fuel injection system damage (gasoline engines);
- the injector is faulty (diesel engines).
Unstable engine operation:
- air leak in the injection system, intake manifold or hoses (gasoline engines);
- the fuel filter is clogged;
- malfunction or low fuel supply pressure of the fuel pump (gasoline engines);
- the fuel tank drain hole or fuel lines are clogged;
- fuel injection system damage (gasoline engines);
- the injectors are faulty (diesel engines).
Low engine power output:
- the timing belt is not installed correctly;
- the fuel filter is clogged;
- fuel pump faulty or low fuel pressure;
- uneven or low compression in the cylinders;
- the interelectrode gap is incorrectly adjusted or the spark plugs are worn out (gasoline engines);
- air leak in the injection system, intake manifold or hoses (gasoline engines);
- fuel injection system is faulty (gasoline engines);
- the injectors are faulty (diesel engines);
- fuel injection timing of the fuel pump is set incorrectly (diesel engines);
- brake sticking;
- clutch slippage.
Backfires in the engine:
- the timing belt is not installed correctly;
- air leak in the injection system, intake manifold or hoses (gasoline engines);
- fuel injection system damage (gasoline engines).
Low engine oil pressure:
- low oil level or wrong grade of oil;
- the oil pressure sensor is faulty;
- engine bearings or oil pump are worn out;
- engine overheating;
- oil pressure relief valve is faulty;
- the oil receiver mesh filter is dirty.
The engine runs after the ignition is turned off:
- excessive carbon deposits in combustion chambers;
- engine overheating;
- fuel injection system damage (gasoline engines);
- the electromagnetic engine stop valve is faulty (diesel engines).
Engine noises
Engine detonation during acceleration:
- the ignition timing is set incorrectly (gasoline engines);
- spark plug type does not match required;
- low octane fuel;
- air leak in the injection system, intake manifold or hoses (gasoline engines);
- excessive carbon deposits in combustion chambers;
- fuel injection system damage (gasoline engines).
Whistling or wheezing noises:
- intake manifold or throttle body gasket is leaking (gasoline engines);
- exhaust manifold gasket leaking;
- vacuum hoses are leaky;
- the cylinder head gasket is blown.
Rattling noises:
- the valve mechanism or camshaft is worn out;
- wear of auxiliary engine components (water pump, generator, etc.).
Detonation or dull noises:
- the lower connecting rod head bearings are worn out (noise decreases under load);
- main bearings are worn out (noise increases under load);
- piston strikes (especially on a cold engine);
- engine auxiliary components are faulty (water pump, generator, etc.).

Visitor comments