Thursday, September 4, 2014

Common Causes of Spark Plug Failure

The spark plug is one of the most important components in the fuel injection system of an automobile.

Electric fuel pump
It ignites the air/fuel mixture in the combustion chamber. The spark plug is mostly used in gasoline engines. A bad or worn out spark plug can affect the performance of the engine, fuel economy and even can lead to starting problems. The failure of spark plug is one of the main reasons for breakdown of vehicles.

In this article, let us discuss some of the common causes of spark plug failure. The common causes of spark plug failure are fouling, wear out/cracks and overheat.

Let us consider the role fouling. Fouling includes carbon fouling and oil fouling.

Carbon fouling
  • Carbon fouling is a common cause of spark plug failure. Carbon fouling means accumulation of carbon deposits on the spark plug.
  • The accumulation of carbon deposits happens due to choking, which leads the air filter being blocked.
  • If the car is idle for a long time, the temperature drops. Due to temperature drop the combustion deposits on the spark plug are not burnt and develops into a thick black carbon near the spark plug causing carbon fouling. You can find the deposits of carbon the spark plug visually.
Oil fouling
  • Oil fouling occurs due to the presence of oil in the combustion chamber.
  • The oil enters the combustion chamber through the piston or walls of the cylinders when they are worn out. The oil enters the combustion chamber due to disproportionate oil to fuel ratio.
Engine overheating
  • If the operating temperature of the engine is more than 1600° F, it overheats the cylinder and damages the firing-end and electrodes of the spark plug.
  • Overheating of the spark plug can also cause abnormal combustion.
Mechanical damage
The threads of the spark plug can get damaged due to improper handling while installing. Damaged spark plugs result in voltage leak in the cylinders.

Worn out spark plugs

  • The firing end of the spark plug wears out.
  • The gap between the electrodes will become wider when the spark plug is used for a long time.
  • Due to this, normal voltage may not be sufficient to ignite the combustion chamber.
  • A worn out spark plug leads to misfiring and causes starting problem.
Poor acceleration
  • Another common sign of failure of spark plug is poor acceleration.
  • Due to this, acceleration pushes down and does not immediately boost the speed of the vehicle.
  • Even it appears like the engine is trying hard to pull the vehicle due to the poor acceleration.
Regular maintenance can improve the performance of the spark plug and it is likely to last longer.