Should you replace all coil packs or just one?
You can of course change just one coil. However, as a mechanic I’ve seen it so many times, when one coil fails another isn’t too far behind. If your coils are easy to access, replacing them as they fail is OK, apart from the inconvenience. It is possible to drive a car with a faulty coil but it isn’t advised.
Why would the same coil pack keep going bad?
If an engine is experiencing repeated coil failures, the coils may be working too hard. The underlying cause may be high secondary resistance (worn spark plugs or excessive spark plug gap), or in rare cases a lean fuel condition (dirty injectors, vacuum leak or leaky EGR valve).
What are the symptoms of a bad coil pack?
Common Symptoms of a Faulty Coil Pack
- A rough idle.
- An unexplainably louder-than-usual engine.
- A noticeable lack of power.
- A significant drop in RPMs while accelerating for no apparent reason.
- A blinking or intermittently activating check engine light.
- An active gas warning light when the vehicle has plenty of gasoline.
What mileage should coil packs be replaced?
While ignition coils do not have a service interval, they do have a lifespan. There is no specific mileage or age to replace them. They should only be replaced when they are bad. If you notice any cracks on the plastic or epoxy, and of course misfires, then it is time to replace the ignition coils.
Can a coil pack go bad from sitting?
12 volts would kill them in short order but even at 7 they are becoming damaged every time the coil fires. It may seem odd to lead off with a short tutorial like that but when a car sits, that arcing damage on the point faces start to corrode. When the corrosion builds up the gap closes and the car won’t run.
How many years do ignition coils last?
Federal law in the United States dictates that the ignition coil and ignition module on new vehicles are warranted for at least two years or 24,000 miles, whichever occurs first. The insulation in the ignition coil will degrade over time, but many coils are designed to last 100,000 miles or more.