There are two occasions when I check the spark plug: right before long drives, and when I hear something irregular in the way my engine runs. Most of the time, the smooth sand paper smoothens the ride. If symptoms persist -- or so the doctors say -- I consider changing the spark plugs.
I'm concerned that my approach may be too simplistic. Are there other symptoms I should consider before changing the spark plugs?
I'm concerned that my approach may be too simplistic. Are there other symptoms I should consider before changing the spark plugs?