Why does a person change spark plugs? Out of a hundred other reasons, changing the spark plugs keeps the engine performance on par and saves us from unexpected hassles. But check engine light glowing even after installing a new spark plug seems odd.
If the “check engine” light (CEL) glows just after you replace the old spark plugs, then there is a big chance that the installation has gone wrong. In this case, going through the installation again is the best option.
Check Engine Light On after Changing Spark Plugs: The Reasons
Everyone knows what fuel lights indicate. They remind you that your fuel tank is nearly empty.
Similarly, the check engine light is the troubleshooting notification of the engine. You might wonder why this indicator blinks after changing spark plugs? As we all know new spark plugs should bring out the actual performance of an engine.
I think checking the engine light after putting in the new plugs can happen if-
- Incompatible ignitor plugs
- Installed in a wrong way
- Inaccurate adjustment of the spark plugs
- Faulty spark plugs
- Some other issues might have appeared (apart from spark plugs)
1. Putting the Wrong One
There is no problem if all of the plugs from every cylinder are from different brands unless they have different criteria. Mismatch of spark plugs disrupts the normal engine performance. Check engine lights appear to be glowing when such things happen.
Knocking: Engine knock or detonation occurs when each cylinder has different types of sparking plugs. Sometimes, the newly installed with less capability can put massive tension on older ones.
Fouling: When the sparker doesn’t cope or match with the pistons, gaps, and fuel, car mileage decreases, and fouling occurs inside the engine.
Mismatch with other ignition parts: There’s a little possibility that other ignition parts, coils, and distributors can’t provide enough support to your new sparking plug. It rarely happens as most ignition coils can work with every sort of plug. Your coil might have become old and lost potential.
Misfiring: High-performance engines can’t get full utility from normal plugs. For example, copper cores melt quickly and misfire when you use them in “Iridium plug preferred” engines. This situation can also trouble you with oil fouling.
2. Inaccurate Installation
Most car enthusiasts try to replace old ignition plugs themselves. Because hiring a mechanic for a job that can be done within minutes might seem like an extra cost.
Generally speaking, people think this is a quick job and don’t want to spend too much time on it. In a rush, they might miss a thing or two. Which puts a bad impact on the vehicle’s longevity.
Here are the most common mistakes car owners make in replacing spark plugs themselves-
Wrong tools: The best tools for putting a new plug-in are torque wrenches and socket wrenches. Other types of wrenches can’t torque plugs precisely. Thus, using them leads to functions going wrong.
Mistorquing: There’s a specific extent to torquing a spark plug. Check the package body or manual inside the package for torquing range indication. Tightening an ignition plug more or less than the advised range causes overheating, misfiring, and especially fouling.
Disconnected wires: Before changing plugs, you surely separate coils and distributors along with their wires. But after stationing plugs, if any wires stay disconnected, the new plug can’t work. Keeping a part or full cylinder of the engine bare is a major flaw in the system. That’s why CEL notifies the driver.
Not Gapped: Most modern-day plugs come pre-gapped. You can find some not pre-gapped in rare cases. Installing an ungapped sparker might cause the check engine indicator to glow up.
New yet bad plug: If all of those issues are not similar to your situation, then you can consider the spark plug you bought as a dead one. Go back to the shop and claim the warranty as soon as possible.
Other Reasons for CEL Blinks
Spark plugs being bad or their wrong installation is a few of the many reasons behind CEL blinks. It can light up for many other reasons as well. There are hundreds of functioning parts inside an engine. If any of the parts malfunction or get desynchronized CE will light up. But that’s a discussion for another day!
If you see check engine light again after adding a new plug to your engine, then it’s sure that another part has been damaged recently. Better if you take your car to a mechanic in this situation. Otherwise, you can’t detect the exact issue before any major damage to the vehicle.
What if Check Engine Light is Flashing Rather than Blinking?
The way CEL illuminates also indicates how severe the engine issue can be. When the check engine light stays on without any blinks, it means the driver should immediately stop the engine and ask for a tow truck to take the vehicle to a garage.
Normally, flashing indicates any of the engine components is totally dead. It can happen because of immense stress from detonation, misfiring, or fuel lacking. Better if you do the repairing while the CEL is still blinking and not flashing.
How to Solve this Issue?
Obviously, you need to do something and solve the issue created by installing new ignition plugs. Not too many things to do when you intend to fix the blunder in stationing. You either,
- Do the installing again, or
- Go to a mechanic for a reliable solution.
If I were a novice and yet to get handy with my vehicle’s engine, I would definitely seek help from an expert automobile mechanic. Because my method has already been proven.
CEL blinks shouldn’t be taken lightly. Instead, try not to use the car for any long drives. Test every part manually. You can at least know what’s causing the trouble even if you don’t know the solution.
Greetings from James Milan. I am an Automotive enthusiast and car repairing expert for over 12 years. Blogging is one of my hobbies. According to my interest, I’ve started this blog to share my thoughts about the Automotive sectors and hope you’ll love it.