1. Incomplete combustion: When spark plugs are worn out, they may not produce a strong enough spark to fully ignite the air-fuel mixture in the engine's cylinders. This results in incomplete combustion, where not all the fuel is burned effectively. As a consequence, the engine loses power and efficiency.
2. Misfiring: Bad spark plugs can also lead to misfires, which occur when one or more cylinders fail to fire properly due to a lack of ignition. Misfires can cause the engine to run rough, hesitate, and lose power.
3. Backfiring in the intake manifold: In some cases, particularly with severe misfiring, the unburned fuel mixture can be pushed back into the intake manifold during the exhaust stroke. When the intake valve opens again, the raw fuel may come into contact with hot surfaces, such as the valves or the manifold itself. This can ignite the mixture, causing a backfire in the intake manifold.
The backfire creates a sudden and violent explosion in the intake manifold, which can produce a loud popping or banging sound. It can also cause damage to the intake manifold, throttle body, and other components in the intake system.
In addition to causing power loss and backfiring, bad spark plugs can also lead to increased emissions, rough idling, and poor fuel economy. If you experience any of these symptoms, it's essential to have your spark plugs checked by a qualified mechanic.
