Spark plugs are one of those maintenance items ... Misfires, especially, will usually trigger a check engine light, but other symptoms of a bad plug are often undetectable by a vehicle's onboard ...

At this point it could be anything from a fouled spark plug to a load of bad gas. When mysterious trouble ... Are all your spark plugs and wires good? Is there fuel in the tank?

However, if your car is guzzling more fuel than usual or has symptoms like rough idling or hard starting, it may be time to replace the plugs. Not only will bad spark plugs diminish your car's ...

The other telltale symptoms of bad diesel glow plugs include rough idling, misfiring, and lousy fuel economy, the same signs you'll notice when a spark plug goes haywire. Fortunately, glow plugs ...