JSmith
CEG'er
sometimes just looking at the spark plugs can tell you a lot too.
The spark plugs, after a few hundred miles, should develop an even dull, greyish, tan color on the end of the barrel and the electrodes except for the areas that the spark jumps between, that's normal. Its also ok if the tips of the electrodes are a light tan to a dull white, that just means the driver likes to step on the gas hard and enjoy the sounds and sensations of a powerful engine.
If its a dull black that rubs off easily, the engine is too rich.
If the plug has lumpy black deposits that are hard to get off the engine is burning oil.
If the whole tip of the barrel and electrodes of the spark plug are covered with a flaky white deposit or are deformed and look like melted wax that's bad. It means several things could be wrong, the spark plugs are simply too "hot" and need to be replaced with "cooler" ones, the engine has been burning poor or too low octane fuel, or the engine is overheating. This can sometimes happen to people who use the factory recommended spark plugs when they use the car for racing. Using the next cooler plug usually solves the problem.
The "heat" of a spark plug refers to how quickly the spark plug conducts heat from the electrodes into the cylinder head. A cooler spark plug will conduct the heat away from the electrodes slower than a hotter plug. The spark plug needs to reach a certain temperature in order to keep from getting fouled or dirty.
Over time it is normal for the outer and inner electrodes to have their edges erode and become rounded, its also normal to see an indentation form on the side of the outer electrode directly across from the inner. Both of those are caused by spark erosion. Every time a spark jumps across the gap a few molecules of metal are blasted away and after millions of sparks you can start to see it. Eventually the erosion will cause the gap to open up, you can reset the gap with a gaping tool or replace the plugs.
The spark plugs, after a few hundred miles, should develop an even dull, greyish, tan color on the end of the barrel and the electrodes except for the areas that the spark jumps between, that's normal. Its also ok if the tips of the electrodes are a light tan to a dull white, that just means the driver likes to step on the gas hard and enjoy the sounds and sensations of a powerful engine.
If its a dull black that rubs off easily, the engine is too rich.
If the plug has lumpy black deposits that are hard to get off the engine is burning oil.
If the whole tip of the barrel and electrodes of the spark plug are covered with a flaky white deposit or are deformed and look like melted wax that's bad. It means several things could be wrong, the spark plugs are simply too "hot" and need to be replaced with "cooler" ones, the engine has been burning poor or too low octane fuel, or the engine is overheating. This can sometimes happen to people who use the factory recommended spark plugs when they use the car for racing. Using the next cooler plug usually solves the problem.
The "heat" of a spark plug refers to how quickly the spark plug conducts heat from the electrodes into the cylinder head. A cooler spark plug will conduct the heat away from the electrodes slower than a hotter plug. The spark plug needs to reach a certain temperature in order to keep from getting fouled or dirty.
Over time it is normal for the outer and inner electrodes to have their edges erode and become rounded, its also normal to see an indentation form on the side of the outer electrode directly across from the inner. Both of those are caused by spark erosion. Every time a spark jumps across the gap a few molecules of metal are blasted away and after millions of sparks you can start to see it. Eventually the erosion will cause the gap to open up, you can reset the gap with a gaping tool or replace the plugs.