Does It Matter Which Ignition Coil Goes Where? How To Properly Replace Ignition Coils
Among the crucial parts of a vehicle ignition system is the ignition coil, also called a spark coil. It provides a spark plug with the high voltage needed for combustion. Most cars use more than two ignition coils which sometimes mix up during a repair, making owners wonder where to install each.
If you’re wondering, does it matter which ignition coil goes where? The answer is that any coil can go into any cylinder of the same engine. It has been done to diagnose cylinder misfires to detect a failing ignition coil. However, avoid swapping with a foreign ignition coil.
Read on to learn the ways to detect a faulty ignition coil and how to properly install replacements.
Does It Matter Which Ignition Coil Goes Where?
So far, there are four styles of ignition coils, but they all share the same goal of increasing voltage. They step up the voltage between 20,000 and 50,000, which is required in a spark plug to create a spark.
The table shares information about different styles of ignition coils and their abilities to be interchanged.
Ignition Coil style | Description | Ability to Be interchanged |
Ignition coil style | The ignition coil style powers all the spark plugs in an engine. They are used in an ignition system using a distributor. | Not interchangeable since it’s a single coil. |
Coil pack ignition coil | This type has a coil pack that charges voltage for two spark plugs. 2 coils serve a 4-cylinder engine | They can be interchanged or swapped with other coils in the pack |
Direct coil on plug | The direct coil is placed on the coil and doesn’t use spark plug wires | Most are universal and are interchangeable |
External coil on plug (Waste spark) | The waste spark coil is more like a coil on a plug but fires to cylinders. | External coils can be interchanged, though, with coils in the same engine or of the same type. |
How Do Ignition Coils Work?
Ignition coils were invented in the early 1900s by American inventor Charles Kettering. The ignition system has improved over time, but the main aim is to provide the engine with a high-voltage spark. The coils step up the 12 volts current from the car batteries through various principles.
Accordingly, the ignition coil has an iron core in the middle surrounded by two coils of wire. When the engine starts, the larger primary coils create a magnetic field that increases the 12 volts by 10 or 20 times. The secondary coils then multiply the voltage by over 100 times to achieve the large volts required.
What Are the Signs That Ignition Coil Needs Replacement?
With time, like other mechanical parts, the ignition coils wear out and require replacement. However, most drivers won’t immediately realize the problem and most times they mistake it for other faults. The noticeable signs of failing ignition coils include
- Cylinder misfire – As the plug fails to create a spark at the top of the compression cycle.
- Trouble starting – It happens because the coils provide the spark plugs with power to start the engine. So if it fails, the engine fails too.
- Rough acceleration – Due to the failing cylinders, the engine doesn’t reach its full potential.
- Dark exhaust – A failing combustion directly affects the catalytic converter, which filters harmful gasses resulting in dark smoke from the tailpipe.
- High fuel usage – With the missing ignitions a lot of the fuel goes unburnt and takes much more to achieve the required RPM.
- Check engine light – Modern cars will display either a misfire code (P0300-P0312) or an ignition coil code (P0350+P0362).
- Rough idling – The car’s RPM will fluctuate, falling below the minimum idle speed of 600 RPM in most cars.
How Do You Properly Replace an Ignition coil?
Ignition coils are easy to replace and most times don’t require a professional. You can refer to your car manual to learn the safety steps and the kind of ignition coils in your engine. Since some are universal, you must get the numbers and style right.
Follow the steps below to replace the ignition coil
Step 1: Get your tools ready (wrench, marker, spark tester to check the coil).
Step 2: Disconnect the battery’s negative terminal before the positive one to minimize the possibility of an electric shock.
Step 3: Locate the faulty ignition coil, which is one or more depending on the number of cylinders in your engine.
Step 4: Mark the ignition cable of the affected ignition coils and then disconnect them carefully.
Step 5: Unscrew the coil bolts using a wrench.
Step 6: Pull the faulty ignition coil or coils out of the engine.
Step 7: Compare if the replacement coil resembles the old coil before proceeding.
Step 8: Oil the new ignition coil and screw it into position.
Step 9: Connect the ignition cables of the replaced ignition coils.
Step 10: Reconnect the battery, beginning with the positive terminal and then the negative.
After replacement, start the engine to test the new coil and observe the changes. If the signs of faulty ignition are still evident, you might have more than one ignition coil problem. However, if you mix up the coils during replacement, don’t worry since most cars can work from any cylinder if they’re the same.
How Long Do Ignition Coils Last?
Most styles of ignition coils last over 100,000 miles. The main cause of damage on the coil is wear and tear, which with proper maintenance is less likely. So it’s best to check the ignition coils annually to spot and replace the failed ones.
A new ignition costs between $50 and $300 to replace, depending on the vehicle. It’s okay to replace the one failing ignition coil, but you can also replace all. Besides, it’s also a good practice to replace the spark plugs at the same time to ensure maximum performance.
Key Takeaways
While spark plugs are necessary to provide a spark, the actual voltage is created by the ignition coil. The coils come in several styles and can be used either single or multiple in an engine. However, since most modern coils resemble each other, they’re often mixed up during maintenance.
This makes many owners wonder; does it matter which ignition coil goes where? Luckily, most ignitions can go in any cylinder if they are of the same style and type. Observe the different signs of a bad ignition coil and replace it to avoid poor performance and engine failure.
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