What is the reason for one cylinder not working in the engine?

From a mechanic’s perspective, a dead cylinder often stems from ignition failure. A worn spark plug or faulty coil pack can halt combustion entirely. For instance, a Vauxhall Corsa with a misfire may show error codes like P0300 (random misfire). Quick checks:

1. Swap the suspect spark plug with another cylinder—if the misfire moves, replace the plug.
2. Test the coil pack with a multimeter. Ignition issues are among the easiest to fix but should not be ignored.

A non-functioning engine cylinder is typically caused by one of four key issues: ignition system failure, fuel delivery problems, mechanical faults, or compression loss. Ignition issues, such as a faulty spark plug or ignition coil, prevent combustion. Fuel delivery problems, like a clogged injector, starve the cylinder of petrol. Mechanical faults, including a broken valve or piston ring, disrupt engine operation. Low compression, often due to a blown head gasket, prevents proper air-fuel mixture sealing.

To diagnose:

1. Check spark plugs and ignition coils for wear or damage.
2. Inspect fuel injectors for blockages or malfunctions.
3. Perform a compression test to identify leaks or mechanical failures.
4. Listen for unusual noises indicating internal damage.

Common symptoms include rough idling, reduced power, and increased fuel consumption. For example, a Ford Focus with a misfiring cylinder may exhibit a noticeable vibration. Addressing the issue promptly prevents further damage, such as catalytic converter failure. If unsure, consult a mechanic for a thorough diagnosis.

The causes of a misfire in one engine cylinder include ignition system failure, wiring system failure, and engine malfunction.

Ignition system failure:

Issues such as faulty ignition coils or fuel injectors require inspection of the vehicle's ignition system, immediate replacement of spark plugs, and clearing of the fuel lines.

Wiring system failure:

If one cylinder misfires without causing engine vibration, it is often due to wiring problems. This situation calls for checking the vehicle's wiring for short circuits and inspecting the spark plugs and distributor wires.

Engine malfunction:

Engine issues can stem from various causes, including overheating or poor-quality engine oil. These scenarios are complex and require professional diagnosis at a repair shop or 4S店.