There is a lot of misinformation about spark plugs on the internet. We have been looking at much of it and are amazed by how inaccurate most of it is.
When to Change Them
The best advice about spark plugs that we can provide is that you should change them on your manufacturer's schedule.
Here's why. How much spark your plugs produce is regulated by the brain of your car called an electronic control module or ECM for short. Your ECM is going to decide how much spark your vehicle needs and you will never know when your spark plugs are worn out till an ignition coil fails.
A Bit of Misinformation
All the blogs that say that bad spark plugs will cause your car to consume more fuel, lose power, or cause your car to be hard to start are wrong. Misfires in your engine will cause the check engine light to come on and worn out spark plugs might be part of the repair.
Electronic Control Module
Worn spark plugs alone will not cause your check engine light to come on because the computer can figure out how to compensate the fuel-air mixture and make adjustments. And that is the real problem for the car because the computer will make everything else work harder in your engine and wear other components out more quickly.
Use Manufacturer’s Timing
Some manufacturers require new spark plugs at 60,000 miles, some at 90,000 miles, and some at 105,000. If you own a Dodge Hemi you will need to replace all 16 spark plugs every 30,000 miles. My best advice is read your owner's manual and change your spark plugs on time.
Get the Right Spark Plug
Our second most important advice is to use the correct spark plug. There are many brands of spark plugs. Your manufacturer has deemed only one of those brands correct for your vehicle. So, don't be putting in NGK's in a Ford or Champions in a Chevrolet. They won't work right and you can cause other issues with your vehicle. Ask your auto repair shop to tell you which ones are the correct spark plugs for your vehicle.
Next blog we will enlighten you on the mysterious ignition coils. We hope this information will be useful in taking care of your car.
Kathryn and Sybren,
We can fix anything. We just happen to fix cars.
Friendly & Expert Service Since ‘46
Adolf Hoepfl Garage
4610 N. Shepherd
Houston, TX 77018