How to Identify the Quality of Spark Plugs?

[DiValentina]

To determine the quality of spark plugs, remove them and observe their appearance to assess their condition: 1. If the spark plug shows severe erosion, with signs such as pitting, black streaks, cracks, or melted electrodes, it indicates that the spark plug is damaged; 2. A reddish-brown or rust-like color suggests the spark plug is functioning normally. The working principle of a spark plug is to introduce high-voltage electricity into the combustion chamber, causing it to jump across the electrode gap to produce a spark, which ignites the combustible air-fuel mixture in the cylinder. A car spark plug mainly consists of a terminal nut, insulator, terminal stud, center electrode, side electrode, and shell, with the side electrode welded to the shell.