How to Know When Your Spark Plugs Need Changing

Spark plugs are meant to last a long time, but not a lifetime. Most vehicle manufacturers recommend having them changed between 75,000 and 100,000 miles. Ideally, your spark plugs should be inspected every 30,000 miles, so you have a heads-up when you may need maintenance. However, if you aren’t taking your car to Quanz Auto Body and your current mechanic isn’t keeping an eye out for you, then you may only know your spark plugs need changing because of tell-tale signs, like:

Hard starts, especially in the morning

Spark plugs carry the spark from your distributor/ignition coil to the piston chamber where it ignites the fuel-oxygen mix. Spark plugs that are worn may not effectively carry the spark, resulting in difficult ignition…and that may be especially noticeable with a cold engine.

Hesitation and/or poor acceleration

“Ignition” may refer to the single car-starting event, but your ignition coils and spark plugs continue to ignite the fuel-air mix for as long as your car is running. That’s what creates the power to make it go. If your car is having trouble going—i.e., hesitating after a complete stop and/or slow acceleration—your spark plugs may be the problem.

Power surges

Worn spark plugs do not always “fire” at the right time. Whereas the lack of fire results in hesitation and lack of power, mistimed firing may actually result in a power surge that causes your car to lurch. This sign of worn spark plugs can be especially hazardous on roadways, so do not ignore it!

Diminished fuel economy

Your car needs fuel and fire to go. If you notice you are using more fuel than normal and none of the other fuel efficiency killers, like deflated tires, excessive weight, fuel line leaks, are present, then worn spark plugs could be the culprit.

Check Engine light comes on

In most modern vehicles, a misfire from any cylinder is likely to trigger your Check Engine light. A misfire could point to an issue with your ignition coils or your spark plugs since the code doesn’t differentiate. You will need a mechanic to inspect the system to identify the underlying cause.

If you experience any symptom of potential spark plug wear, bring your car to Quanz Auto Body. We can perform a mechanical inspection to find the problem and generate a free estimate for repairs. Our technicians are ASE-certified, so you can rest assured that our repairs are done right and will get you on the road as quickly as possible.