LDNN

How likely is it for a spark plug to "go bad" and how can we tell if one out of six failed?

Thanks,
LDNN

tedward88

iTrader: (11)

How to tell if spark plugs are bad by looking at them

707IS350

If a spark plus is going bad you will most likely develop a misfire and the engine computer will trigger a check engine light reporting a misfire was detected in a certain cylinder. But if one of the spark plugs is bad you should replace them all as the others will probably start to misfire soon under normal wear and tear.

My0gr81

If you are going to take out a spark plug to look if it is bad, you might as well just replace it with a new one regardless. Peace of mind.