What does detonation look like on spark plugs?
Detonation shows up on the plugs as spotting on the porcelain. There are two different types of spotting seen. One type appears as just black spots and the other appears as little bright spots like diamonds.
What are the symptoms of bad spark plugs?
6 Symptoms of Bad or Failed Spark Plugs 1 Engine misfires. The most common symptom of bad spark plugs is that you will feel misfires from your engine. 2 Check engine light. 3 Rough idle. 4 Slow/rough acceleration. 5 Hard starting condition. 6 Poor fuel economy. …
What does a black spark plug look like?
The round flat circular area of the plug at the end the threads should be dark gray or flat black and should not be sooty. If it is sooty then it can mean that your plug has not been tightened enough and you are sucking and blowing fuel and air past the threads of the plug. Detonation shows up on the plugs as spotting on the porcelain.
How does a spark plug ignite an engine?
The spark plug is the component of your engine that is igniting the cylinder fuel/air mixture. The fuel injectors inject fuel into the combustion chamber, and then the piston is compressing the air-fuel mixture. It’s time for the spark plug to ignite the fuel mixture to push the pistons down in this event.
What does the color of the spark plug mean?
In general, a light tan/gray color tells you that the spark plug is operating at optimum temperature and that the engine is in good condition.
Why does a worn spark plug strain the ignition system?
A worn spark plug not only wastes fuel but also strains the whole ignition system because the expanded gap (due to erosion) requires higher voltages. Normal rates of gap growth are as follows: Abnormal electrode erosion is caused by the effects of corrosion, oxidation and reaction with lead—all resulting in abnormal gap growth.
What should the firing end of a spark plug be?
If the firing end of a spark plug is brown or light gray, the condition can be judged to be good and the spark plug is functioning optimally. Although there are many different cases, if the insulation resistance between the center electrode and the shell is over 10 ohms, the engine can be started normally.
What does lead look like on a spark plug?
Lead fouling usually appears as yellowish brown deposits on the insulator nose. This cannot be detected by a resistance tester at room temperature. Lead compounds combine at different temperatures. Those formed at 370-470°C (700-790°F) have the greatest influence on lead resistance.