Skip the auto shop - Our mechanics make house calls

Q: When Should Engine Spark Plugs Be Replaced?

asked by on

When should engine spark plugs be replaced?

A: Regularly scheduled spark plug replacement ...

Regularly scheduled spark plug replacement should follow the prescribed manufacturer’s recommendations listed in your owner's manual.

With today’s advanced ignition systems and use of exotic materials, spark plugs can live for about 100,000 miles before requiring replacement.

Other reasons to replace your spark plugs would include:

  • Repair of engine misfire issues
  • Worn plugs due to high mileage, long-term storage, or engine performance malfunctions
  • Poor fuel economy
  • Emissions test failures

This is not a comprehensive list by any means.

Spark plugs are vital to the proper operation of your engine. I have personally worked on several vehicles that had close to 250,000 miles on them before coming into the shop for repair. All of the ignition system components (spark plugs, plug wires, ignition coil, distributor cap and rotor) were original to the vehicle and they too had nearly 250,000 miles of wear on them. Needless to say, with the amount of neglect these vehicles showed, the engines were totally worn out and had to be replaced.

Replacing your spark plugs when necessary will help keep your engine running well, get the most mileage from every tank of fuel, and keep those pesky emissions at their lowest levels. Should you need any help with replacing your spark plugs, contact a professional mechanic who can service your vehicle at your convenience.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: Starting problems even though I recently replaced the battery.

I would have a technician look at it and pull codes on the computer and diagnose the problem. It could have jumped timing or have a bad crank sensor or it could be a fuel pump problem, either way it...

Q: How do I check the power steering fluid?

Checking your power steering fluid level is an important part of normal maintenance, and should be one once a month. If the level drops too low, you’ll hear a whining sound while turning, and the system may not work right....

Q: Car idles and multiple trouble codes are triggered

Hi there. If this vehicle is having an idle concern, I have to ask if you may be having a stumble or stall issue when coming to a stop. If so, your vehicle may be covered under a special...

Related articles

P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.