Maintaining your Toyota Prius C is essential to keep it running smoothly, and one of the key maintenance tasks is changing the spark plugs. If you’re ready to take on this project yourself, this guide will walk you through the entire process. It’s not as daunting as it might seem, especially with a few helpful tips along the way.
Watch the video guide HERE
What You’ll Need:
Before you start, make sure you have the following tools and supplies:
- 5/8 spark plug socket
- Extension and swivel (optional but helpful)
- 3/8 ratchet
- Four spark plugs (make sure they’re pre-gapped)
- Dielectric grease
- Anti-seize lubricant
- Power tools for bolt removal (optional)
Pro Tip: Always work on a cool engine to avoid damaging the aluminum engine block.
Step 1: Remove the Engine Cover
To access the spark plugs, you’ll need to remove the engine cover by unscrewing the four 10mm bolts. Using power tools for this step can save you time, but always hand-tighten bolts during reassembly to avoid over-tightening.
Step 2: Disconnect the Throttle Body Clip and Wire Loom
Next, you’ll need to disconnect the throttle body clip and move the wire loom out of the way to create enough space for the job. Simply slide the clip off and pull the pin towards yourself to free the wire loom.
Step 3: Remove the Ignition Coils
Now that you have clear access, you can start removing the ignition coils. Begin with the first coil, which should lift off easily. For the second coil, you’ll need to disconnect it because it might be blocked by a metal pipe. Coils three and four should come out without any additional steps.
Pro Tip: Before you begin, clean the area around the spark plugs using a vacuum or leaf blower to prevent debris from falling into the engine.
Step 4: Inspect and Remove the Old Spark Plugs
With the ignition coils out of the way, you can now remove the spark plugs. It’s a good idea to inspect the spark plug holes at this point. If you notice any oil or excessive dirt, further inspection might be necessary. Fortunately, if you only need to replace the boots, you can purchase them separately without buying new coils.
Step 5: Apply Anti-Seize and Dielectric Grease
Before installing the new spark plugs, apply a small amount of anti-seize lubricant to the threads. This helps prevent the spark plugs from seizing in the cylinder head. Additionally, apply a tiny dab of dielectric grease to the spark plug boots to ensure a good electrical connection and make future removal easier.
Step 6: Install the New Spark Plugs
Carefully drop the new spark plugs into the holes and hand-tighten them. It’s crucial to start them by hand to avoid cross-threading, which can damage the engine block. Once hand-tightened, use your ratchet to give each spark plug a final snug turn—about a fifth of a turn is typically sufficient. You can also use a torque wrench to ensure the correct torque, which usually ranges between 13 to 17 lb-ft, depending on whether you’ve used anti-seize.
Pro Tip: The spark plug socket is designed with a rubber insert to hold the spark plug securely. Make sure it’s seated properly before tightening.
Step 7: Reassemble and Final Checks
After all the spark plugs are installed, reassemble the ignition coils, reconnect the throttle body clip, and reattach the wire loom. Finally, secure the engine cover by hand-tightening the bolts.
Pro Tips for a Smooth Job:
- Use Pre-Gapped Spark Plugs: Always buy pre-gapped spark plugs to avoid the risk of damaging them by attempting to gap them yourself.
- Avoid Opening the Car Door: While working on your Prius, avoid opening the car door, as it could trigger the vehicle’s self-check mode, potentially leading to a check engine light.
- Trust Your Instincts: If something feels off while installing a spark plug, stop and double-check the threads. Forcing a spark plug can cause significant damage.
Congratulations! You’ve successfully changed the spark plugs on your Toyota Prius C. Regular maintenance like this keeps your car running efficiently and can save you money in the long run. Don’t forget to check out other maintenance videos and guides, including those for the PCV valve, brakes, and oil changes.
By following these steps, you’ll not only keep your vehicle in top shape but also gain confidence in your DIY car maintenance skills.
Watch the video guide HERE
