Subaru Outback 2012: Ignition Coil Replacement Guide

by Alex Braham 53 views

Hey guys! Are you having some issues with your 2012 Subaru Outback? Experiencing rough idling, misfires, or a check engine light staring you down? Well, chances are, your ignition coils might be the culprit. Don't worry; this guide will walk you through everything you need to know about replacing the ignition coils on your trusty Subaru Outback. We'll cover why they fail, how to diagnose the problem, and a step-by-step guide to getting those coils swapped out. Let's dive in!

Understanding Ignition Coils

Ignition coils are a crucial component of your car's ignition system. Their primary job is to transform the relatively low voltage from your car's battery into the high voltage needed to create a spark at the spark plugs. This spark ignites the air-fuel mixture in the engine's cylinders, which, in turn, powers your car. Think of them as tiny transformers that give your engine the jolt it needs to run smoothly.

Over time, ignition coils can degrade due to heat, vibration, and the constant electrical stress they endure. When an ignition coil starts to fail, it may not deliver a consistent or strong enough spark, leading to various engine problems. Recognizing the symptoms of a failing ignition coil is the first step in addressing the issue. A faulty ignition coil can cause several noticeable problems in your Subaru Outback. Keep an eye out for these signs:

  • Rough Idling: If your car feels like it's vibrating or shaking excessively while idling, it could be a sign of a misfiring cylinder due to a weak ignition coil.
  • Misfires: Misfires occur when one or more cylinders aren't firing correctly. This can cause a noticeable decrease in engine power and fuel efficiency. You might feel jerking or hesitation during acceleration.
  • Check Engine Light: The check engine light is your car's way of telling you something is wrong. If an ignition coil is failing, the car's computer will likely detect the misfire and trigger the light. Use an OBD-II scanner to read the error codes for a more precise diagnosis.
  • Poor Fuel Economy: A failing ignition coil can lead to incomplete combustion, which means your engine isn't burning fuel as efficiently as it should. This can result in a noticeable drop in your gas mileage.
  • Difficulty Starting: In some cases, a completely failed ignition coil can make it difficult to start your car, especially in cold weather.

Diagnosing a Faulty Ignition Coil

Before you start replacing parts, it's essential to confirm that the ignition coil is indeed the problem. Here's how you can diagnose a faulty ignition coil:

  1. OBD-II Scanner: The easiest way to diagnose an ignition coil issue is with an OBD-II scanner. Plug the scanner into your car's diagnostic port (usually located under the dashboard) and read the error codes. Common codes associated with ignition coil problems include P0300 (random misfire), P0301 (misfire in cylinder 1), P0302 (misfire in cylinder 2), and so on.
  2. Visual Inspection: Check the ignition coils for any visible signs of damage, such as cracks, swelling, or burn marks. Also, inspect the wiring and connectors for corrosion or damage.
  3. Swap Coils: If you suspect a particular ignition coil is failing, you can try swapping it with another coil. For example, if you're getting a P0301 code (misfire in cylinder 1), swap the ignition coil from cylinder 1 with the one from cylinder 2. Clear the error codes and then drive the car. If the misfire code changes to P0302, it confirms that the ignition coil is the problem.
  4. Multimeter Test: Use a multimeter to test the resistance of the ignition coil. Compare the reading to the manufacturer's specifications. A significant deviation from the specified range indicates a faulty coil.

Tools and Materials You'll Need

Okay, so you've confirmed that your ignition coils need replacing. Here's a list of tools and materials you'll need to get the job done:

  • New Ignition Coils: Make sure you buy the correct ignition coils for your 2012 Subaru Outback. Check the part number to ensure compatibility.
  • Socket Set: You'll need a socket set with various sizes to remove the bolts holding the ignition coils in place.
  • Wrench Set: A set of wrenches might be necessary for some of the connections.
  • Screwdrivers: Both Phillips head and flathead screwdrivers can be helpful.
  • OBD-II Scanner: To clear the error codes after replacing the ignition coils.
  • Multimeter: To test the old and new ignition coils if needed.
  • Work Gloves: To protect your hands.
  • Safety Glasses: To protect your eyes.
  • Anti-Seize Compound: To apply to the spark plug threads (if you're replacing the spark plugs at the same time).
  • Dielectric Grease: To apply to the inside of the ignition coil boot to protect the spark plug connection.

Step-by-Step Replacement Guide

Alright, let's get down to the nitty-gritty. Follow these steps to replace the ignition coils on your 2012 Subaru Outback:

  1. Safety First: Disconnect the negative terminal of your car's battery. This will prevent any electrical accidents during the replacement process.
  2. Locate the Ignition Coils: The ignition coils are typically located on top of the engine, directly above the spark plugs. On the Subaru Outback, they are usually easily accessible.
  3. Remove the Engine Cover: If there's an engine cover, remove it to gain access to the ignition coils. This usually involves unscrewing a few bolts or clips.
  4. Disconnect the Electrical Connector: Each ignition coil will have an electrical connector attached to it. Gently squeeze the connector and pull it off the ignition coil. Be careful not to damage the connector.
  5. Remove the Ignition Coil: Use a socket or wrench to remove the bolt holding the ignition coil in place. Once the bolt is removed, carefully pull the ignition coil straight up and out of the engine. You might need to wiggle it a bit to loosen it.
  6. Inspect the Spark Plug: Now that the ignition coil is removed, take a look at the spark plug. If it looks worn or damaged, consider replacing it. Apply a small amount of anti-seize compound to the spark plug threads before installing the new one.
  7. Install the New Ignition Coil: Apply a small amount of dielectric grease to the inside of the ignition coil boot. This will help protect the spark plug connection and prevent corrosion. Place the new ignition coil into the engine and secure it with the bolt. Make sure it's snug but not overtightened.
  8. Reconnect the Electrical Connector: Reattach the electrical connector to the new ignition coil. Make sure it clicks into place.
  9. Repeat for Remaining Coils: Repeat steps 4-8 for the remaining ignition coils.
  10. Reinstall the Engine Cover: If you removed an engine cover, reinstall it.
  11. Reconnect the Battery: Reconnect the negative terminal of your car's battery.
  12. Clear the Error Codes: Use an OBD-II scanner to clear any error codes that may have been triggered during the replacement process.
  13. Test Drive: Take your Subaru Outback for a test drive to make sure everything is running smoothly. Pay attention to any unusual noises or vibrations.

Tips and Tricks

Here are a few extra tips to make the ignition coil replacement process even smoother:

  • Replace All Coils at Once: If one ignition coil has failed, it's likely that the others are nearing the end of their lifespan as well. Replacing all the ignition coils at the same time can save you time and hassle in the long run.
  • Use Dielectric Grease: Applying dielectric grease to the inside of the ignition coil boot is crucial for protecting the spark plug connection. Don't skip this step!
  • Check the Spark Plugs: Since you're already working on the ignition system, it's a good idea to check the spark plugs. Replace them if they're worn or damaged.
  • Take Your Time: Don't rush the replacement process. Take your time and make sure everything is done correctly.
  • Consult a Professional: If you're not comfortable working on your car, don't hesitate to consult a professional mechanic.

Conclusion

Replacing the ignition coils on your 2012 Subaru Outback is a relatively straightforward task that can save you money on expensive mechanic fees. By following this guide, you can diagnose the problem, gather the necessary tools and materials, and replace the ignition coils yourself. Remember to take your time, be careful, and always prioritize safety. Happy wrenching, and keep your Outback running smoothly!