When spark plugs begin to misfire, you may notice unusual noises from the force of the pistons and combustion not working properly. Pistons travel at high velocities; if the spark plug fires at the wrong time, this could lead to constant rattling, pinging or knocking sounds.
If your car is having trouble starting or just feels disjointed and jerky, your spark plugs may not be working right. This can lead to misfires and erratic performance.
Spark plugs fire when you accelerate and change gears. If the spark that the plug generates isn't functioning at 100 percent, your vehicle performance will be poor, and you'll experience a sluggish and fuel-wasting drive.
Lots of things can lead to poor fuel economy. In the case of old spark plugs, fuel is wasted because your vehicle fails to receive the proper, heat-generating spark at the right time.
Drivers should consult their owner's manual for the vehicle manufacturer's recommended spark plug replacement intervals. The Car Care Council also recommends replacing all of the plugs at the same time and with the same type of spark plug that the vehicle was originally equipped.
"Replacing spark plugs is a relatively inexpensive maintenance task and can be performed by a do-it-yourselfer or by a professional technician at any auto repair shop," said White.
SOURCE: Car Care Council