A Guide to Spark Plug Replacement for the 2016 Scion iA
Keep your 1.5L engine running smoothly with the right set of new spark plugs.
- The 2016 Scion iA requires four Iridium-type spark plugs for best performance and longevity.
- Choose top-tier aftermarket brands like NGK or Bosch, which are often the original equipment suppliers.
- Do not use anti-seize compound on new NGK or Denso plugs; they have a special coating.
- Replacement is a simple DIY task that requires basic tools and can be done in under an hour.
Signs of a Failing Spark Plug
When spark plugs wear out, they can't create a strong enough spark. This can cause several problems with your Scion iA. You might notice one or more of these symptoms:
- Rough Idling: Your car may shake or vibrate when you're stopped at a light.
- Hard Starts: The engine might take longer than usual to start, or you might have to crank it a few times.
- Poor Acceleration: The car may feel sluggish or slow to respond when you press the gas pedal.
- Worse Fuel Economy: If you're stopping for gas more often, worn plugs could be the reason.
- Check Engine Light: A failing spark plug can cause an engine misfire, which will trigger the check engine light. 🎬 Watch: 7 symptoms of a bad spark plug to ignore.
Choosing the Right Aftermarket Spark Plug
The 2016 Scion iA came from the factory with long-lasting Iridium spark plugs, typically made by Denso or NGK. When shopping for aftermarket replacements, sticking with this technology is your best bet for performance and longevity. Aftermarket plugs are often the exact same as the original parts, just sold in a different box.
Brand Quality Tiers for Scion iA
Top Tier - OEM Equivalents (NGK, Bosch):
- NGK: Widely considered the original equipment standard for most Japanese vehicles. Their Laser Iridium and Iridium IX series are excellent choices that meet or exceed factory specifications for the iA. They are known for reliability and long life right out of the box.
- Bosch: A top-quality German brand with a strong reputation. Their Double Iridium plugs are a direct competitor to NGK and offer excellent performance and a long service life.
Mid-Grade (Champion):
- Champion: An established American brand that offers a range of plug types, including Iridium and Platinum options for the iA. While they are a reliable choice, NGK and Bosch are more commonly associated with the original equipment for Japanese vehicles.
A Note on Plug Material
Your iA was designed for Iridium spark plugs. While cheaper copper or platinum plugs might be available, using them can lead to shorter replacement intervals and reduced engine performance. For the small difference in price, Iridium plugs provide the best performance and can last up to 100,000 miles.
Known Issues, Recalls, or TSBs
Searches for spark plug-specific recalls, technical service bulletins (TSBs), or widespread problems for the 2016 Scion iA came up empty. This is a reliable part on a reliable vehicle. Some owners in forums have noted that the original factory-installed plugs can be very tight to remove, so be prepared to use steady force. Always work on a cool engine to prevent damage to the aluminum cylinder head.
🎬 Watch: How to change spark plugs on the 1.5L engine.DIY Replacement Tips
Replacing the spark plugs on the iA is a very manageable DIY job that can be done in under an hour.
🎬 See this step-by-step 2016 Scion iA spark plug replacement walkthrough.- Let the engine cool completely.
- Remove the plastic engine cover.
- Disconnect the negative battery terminal with a 10mm wrench.
- Unplug the electrical connectors from the four ignition coils and use an 8mm socket to remove the bolt holding each coil in place.
- Gently pull the ignition coils straight up and out.
- Use a spark plug socket with an extension to remove the old plugs.
- Install the new plugs. They should be pre-gapped, so do not try to adjust the gap on Iridium plugs.
- Pro-Tip: Do not use anti-seize compound on NGK or Denso plugs. They have a special coating that prevents seizing, and adding anti-seize can cause you to overtighten and damage them.
- Tighten the new plugs to the correct torque specification, which is 11-14 ft-lbs. Reinstall the coils, connect the battery, and start the engine.
Frequently Asked Questions
How often should I change the spark plugs on my 2016 Scion iA?
The recommended interval for the original Iridium plugs is between 75,000 and 100,000 miles. Some maintenance schedules suggest checking them earlier, but replacement isn't usually needed before then unless you are experiencing problems.
Is there a difference between OEM and aftermarket spark plugs for my iA?
Often, there is no quality difference. Brands like NGK and Denso are original equipment manufacturers, meaning they make the parts for Toyota/Scion. An aftermarket NGK or Denso plug is frequently the exact same part you would get from a dealership, just in different packaging.
Do I need to gap the new spark plugs?
No. High-quality Iridium spark plugs from brands like NGK, Bosch, and Denso come pre-gapped from the factory. Attempting to adjust the fine Iridium tip can easily damage it. It's a good idea to check the gap, but you should not need to change it.
Should I use anti-seize on the threads?
No. The major OEM-equivalent brands like NGK and Denso specifically advise against using anti-seize. Their plugs have a special trivalent coating that acts as its own anti-seize and ensures proper torque readings. Adding more can lead to over-tightening and potential engine damage.
Helpful Videos
Technical Specifications
OEM Part Numbers: PE5R-18-110
The 2016 Scion iA uses four Iridium spark plugs. Recommended brands like NGK and Denso come pre-gapped (around 0.040 inches) and should not be adjusted. The proper torque specification during installation is 11-14 ft-lbs.
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The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- Scion iA: