Continuing with the advice on how to visually check spark plugs and when to change them , this time we'll talk about issues that affect ignition and electrical faults that quickly damage spark plugs.
Quite different from problems related to deposits , electrical failures that can destroy a spark plug are a serious problem for the engine, and can even cause serious damage to the integrity of the car.
It is always advisable to check the spark plug wires , thus preventing short circuits and further damage.
One of the most common problems is excessive heat in the spark plug area , caused by water in the cooling system, very lean mixtures (which generate excessive combustion temperature), and engine ignition-related problems.
This is diagnosed visually by noting the completely white insulator , without deposits or damage, in contrast to completely eroded electrodes, with very advanced damage.
When we find pre-ignition faults, the spark plug has a completely melted, damaged or missing center electrode , with the insulator blackened or semi-melted.
This fault is caused by pre-ignition in the combustion chamber , so we must check if the spark plug is suitable for that car, appropriate for the normal operation of the engine and if the amount of spark it produces is tolerated by the chamber.
If this is so, then the fault is related to a bad mixture, or to the accumulation of particles in the combustion chamber.