Engine fault detection (Opel Vectra A)

The engine does not start

• The contacts of the wires with the battery terminals are loose or corroded (Section 1)
• Low or defective battery (Section 5)
• The wiring in the starter circuit is faulty, loose or open (Section 5)
• The traction relay or starter switch is faulty (Section 5)

Starter faulty (Section 5)

• Electric starter pinion or flywheel ring gear teeth are loose or broken (Sections 2 and 5)
• The engine ground is damaged or disconnected (Section 5)

The engine turns over but does not start

• The fuel tank is empty
• The battery is discharged (the engine is turning slowly) (Section 5)
• The connections between the wires and the battery terminals are loose or corroded (Section 1)
• Spark plugs are worn, faulty or installed with incorrect gap (Section 1)
• The choke mechanism is incorrectly adjusted, worn out or sticking - carburetor models (Section 4A)
• Damaged fuel shut-off valve winding - carburetor models (Section 4A).
• Damage to the fuel injection system - fuel injected models (Section 4B).
• Major mechanical failure (for example, camshaft drive) (Chapter 2A or 2B)

The engine is difficult to start from the anode state

• The battery is discharged (Section 5)
• Loose or corroded battery terminal connections (Section 1)
• Spark plugs are worn, faulty or installed with incorrect gap (Section 1)
• The choke mechanism is incorrectly adjusted, worn out or sticking - carburetor models (Section 4A)
• Damage to the fuel injection system - fuel injected models (Section 4B)
• Other damage to the ignition system (Sections 1 and 5)
• Low compression in engine cylinders (Section 2A)

The engine is difficult to start when it is hot

• The air filter element is dirty or clogged (Section 1)
• The choke mechanism is incorrectly adjusted, worn out or sticking - carburetor models (Section 4A)
• Damage to the fuel injection system - fuel injected models (Section 4B)
• Low compression in engine cylinders (Section 2A)

[Information taken from the website: Opelbook.ru]

The starter is noisy

• Electric starter pinion or flywheel ring gear teeth are loose or broken (Sections 2 and 5)
• Starter mounting bolts are loose or missing (Section 5)
• The internal components of the starter are worn or damaged (Section 5)

The engine starts but immediately stalls

• The ignition circuit connectors are loose or faulty (Sections 1 and 5)
• Vacuum leak in carburetor body or intake manifold (Section 4A or 4B)
• The jets or internal channels of the carburetor are clogged (Section 4A)
• Clogged injector/damage to fuel injection system - fuel injection models (Section 4B)

Unstable operation in idle mode

• The air filter element is clogged (Section 1)
• Vacuum leak in the carburetor body, intake manifold, or associated hoses (Section 4A or 4B)
• Spark plugs are worn, faulty or installed with incorrect gap (Section 1)
• Uneven or low compression in engine cylinders (Section 2A)
• The camshaft lobes are worn (Section 2A or 2B)
• Drive belt tension is incorrect (Section 2A or 2B)
• The jets or internal channels of the carburetor are clogged (Section 4A)
• Clogged injector/damage to fuel injection system - fuel injection models (Section 4B)

Misfiring in idle mode

• Spark plugs are worn, faulty or installed with incorrect gap (Section 1)
• The spark plug high voltage wiring is faulty (Section 1)
• Vacuum leak in the carburetor body, intake manifold, or associated hoses (Section 4A or 4B)
• The jets or internal channels of the carburetor are clogged (Section 4A)
• Clogged injector/damage to fuel injection system - fuel injection models (Section 4B)
• The distributor cap is cracked (Section 1)
• Uneven or low compression in engine cylinders (Section 2A)
• The crankcase ventilation hoses are disconnected or damaged (Section 4A)

Misfires across the entire speed range

• The fuel filter is clogged (Section 1)
• The fuel pump is faulty or the supply pressure is low (Section 4A or 4B)
• Fuel tank holes or fuel lines are clogged (Section 4A or 4B)
• Vacuum leak in the carburetor body, intake manifold, or associated hoses (Section 4A or 4B)
• Spark plugs are worn, faulty or installed with incorrect gap (Section 1)
• The spark plug high voltage wiring is faulty (Section 1)
• The distributor cap is cracked (Section 1).
• The ignition coil is faulty (Section 5)
• Uneven or low compression in engine cylinders (Section 2A)
• Clogged jets or internal channels of the carburetor - carburetor models (Section 4A)
• Clogged injector/damage to fuel injection system - fuel injection models (Section 4B).

The engine accelerates with a delay

• Spark plugs are worn, faulty or installed with incorrect gap (Section 1)
• Vacuum leak in the carburetor body, intake manifold, or associated hoses (Section 4A or 4B)
• The jets or internal channels of the carburetor are clogged (Section 4A)
• Clogged injector/damage to fuel injection system - fuel injection models (Section 4B).

The engine stalls

• Vacuum leak in the carburetor body, intake manifold, or associated hoses (Section 4A or 4B)
• The fuel filter is clogged (Section 1)
• The fuel pump is faulty or the supply pressure is low (Section 4A or 4B)
• Block the fuel tank opening or fuel lines (Section 4A or 4B)
• The jets or internal channels of the carburetor are clogged (Section 4A)
• Clogged injector/damage to fuel injection system - fuel injection models (Section 4B)

Insufficient engine power

• Drive belt is installed or tensioned incorrectly (Section 2A or 2B)
• The fuel filter is clogged (Section 1)
• The fuel pump is faulty or the supply pressure is low (Section 4A or 4B)
• Uneven or low compression in engine cylinders (Section 2A)
• Spark plugs are worn, faulty or installed with incorrect gap (Section 1)
• Vacuum leak in the carburetor body, intake manifold, or associated hoses (Section 4A or 4B)
• The jets or internal channels of the carburetor are clogged (Section 4A)
• Clogged injector/damage to fuel injection system - fuel injection models (Section 4B)
• Wheel braking (Section 1 and Section 9)
• Clutch slippage (Section 6)

Engine backfires

• Drive belt is installed or tensioned incorrectly (Section 2A or 2B)
• Vacuum leak in the carburetor body, intake manifold, or associated hoses (Section 4A or 4B)
• The jets or internal channels of the carburetor are clogged (Section 4A)
• Clogged injector/damage to fuel injection system - fuel injection models (Section 4B)

The oil pressure warning light comes on when the engine is running

• Low oil level or wrong type of oil (Section 1)
• The oil pressure sensor is faulty (Section 12)
• Engine bearings and/or oil pump are worn out (Section 2A)
• High engine operating temperature (Section 3)
• The oil pressure reducing valve is faulty (Section 2A)
• The mesh filter of the oil pump inlet pipe is clogged (Section 2A)

The engine continues to run after being turned off

• Excessive carbon deposits in the engine (Section 2A)
• High engine operating temperature (Section 3)
• The fuel shut-off valve is faulty (Section 4A)
• Damage to the fuel injection system - fuel injected models (Section 4B).

Engine noises



Detonation or knocking noise during acceleration or when the vehicle is loaded

• Incorrect ignition timing/malfunction in the ignition system (Section 1)
• The wrong type of spark plugs are installed (Section 1)
• Wrong type of fuel was filled (Section 4)
• Vacuum leak in the carburetor body, intake manifold, or associated hoses (Section 4A or 4B)
• Excessive carbon deposits in the engine (Section 2A)
• The jets or internal channels of the carburetor are clogged (Section 4A)
• Clogged injector/damage to fuel injection system - fuel injection models (Section 4B)

Whistling or hissing sounds

• Intake manifold or carburetor gasket is leaking (Section 4A or 4B)
• The exhaust manifold gasket or the connection between the exhaust pipe and the manifold is leaking (Section 4C)
• Vacuum hose leaking air (Sections 4A, 4B, 4C, 5, 9 and 12)
• The cylinder head gasket has blown (Section 2A or 2B)

Light tapping or rattling

• Worn valve train or camshaft (Section 2A or 2B)
• Auxiliary components are damaged (water pump, generator, etc) (Sections 3, 5 etc.)

Loud or dull knocking sound

• Connecting rod bearings are worn out (regular loud knocking noise, possibly decreasing when the vehicle is loaded) (Chapter 2A or 2B)
• The main bearings are worn out (a loud knocking noise, possibly increasing when the vehicle is loaded) (Chapter 2A or 2B)
• The piston is damaged (most noticeable when the engine is not warmed up) (Section 2A)
• Auxiliary components are damaged (water pump, generator, etc) (Sections 3, 5 etc.)