A Guide to Spark Plugs for the 2016 Scion iM
Keep your iM's 1.8L engine running smoothly with the right set of spark plugs.
- The 2016 Scion iM uses long-life iridium spark plugs with a replacement interval of up to 120,000 miles.
- OEM-equivalent brands like Denso and NGK are highly recommended for best performance and reliability.
- Symptoms of failure include rough idle, poor acceleration, reduced fuel economy, and a check engine light (P030X codes).
- Replacement is a simple DIY task that can be done in under an hour with basic tools.
Signs of Failing Spark Plugs in Your Scion iM
The spark plugs in your iM's 1.8L 2ZR-FAE engine are long-life iridium types, but they will eventually wear out. When they do, you may notice several performance issues. Being aware of these symptoms can help you address the problem before it gets worse.
🎬 Watch a detailed breakdown of common bad spark plug symptoms.- Rough Idling: Your car may shake or vibrate more than usual when you're stopped. This is often caused by an inconsistent spark disrupting the engine's smooth operation.
- Engine Misfires: You might feel a stutter or hesitation from the engine, especially during acceleration. This happens when a plug fails to ignite the fuel mixture correctly.
- Poor Acceleration: If your iM feels sluggish or slow to respond when you press the gas pedal, worn spark plugs could be the cause.
- Reduced Fuel Economy: When spark plugs are not firing efficiently, the engine may burn more fuel than necessary, leading to more frequent stops at the gas station.
- Check Engine Light: A failing or misfiring spark plug can trigger the check engine light. Common codes associated with this issue are in the P0300-P0304 range, indicating a misfire in a specific cylinder.
- Difficulty Starting: A weak spark can make it harder for the engine to start, especially in cold weather.
Choosing the Right Aftermarket Spark Plugs
When it's time for a replacement, you have several options. The original equipment (OEM) spark plugs for the 2016 Scion iM are typically made by Denso or NGK. These are considered top-tier choices and are specifically designed for your vehicle's engine.
Brand Quality Tiers for 2016 Scion iM
| Tier | Brands | Notes |
|---|---|---|
| OEM / Premium Aftermarket | Denso, NGK | Denso and NGK are the original equipment suppliers for most Toyota and Scion vehicles. They offer iridium plugs that provide long life and performance consistent with the factory parts. Choosing either of these brands is a reliable option for a direct replacement. |
| Quality Aftermarket | Bosch | Bosch is a well-known German brand that produces quality iridium spark plugs. While some mechanics prefer to stick with Japanese brands like Denso or NGK for Toyota-family engines, many owners use Bosch plugs without issues. They can be a good alternative if priced competitively. |
| Standard Aftermarket | Champion | Champion offers a range of spark plugs, including platinum and iridium options. While generally considered a standard, reliable brand, they are not as commonly associated with Japanese vehicles as Denso or NGK. They can be a budget-friendly choice, but for long-term reliability, OEM-equivalent brands are often recommended. |
Pro Tip: For Japanese vehicles like your Scion, it's almost always best to stick with the OEM brands, Denso or NGK. These plugs are engineered specifically for the ignition system in your 2ZR-FAE engine and offer the most predictable performance and longevity.
Cost of Replacing Spark Plugs
The cost can vary depending on whether you do the job yourself or have a professional mechanic do it.
| Expense | Estimated Cost |
|---|---|
| Aftermarket Spark Plugs (Set of 4) | $32.00 - $112.84 |
| Shop Labor | $122 - $179 |
| Total Professional Replacement | $199 - $287 |
Known Issues: There are no major recalls or Technical Service Bulletins (TSBs) specifically related to spark plugs for the 2016 Scion iM. The only recall found for this model year relates to an accessory weight label and does not affect engine components.
Frequently Asked Questions (FAQ)
When should I replace the spark plugs on my 2016 Scion iM?
The original iridium spark plugs are designed for a long service life. The manufacturer-recommended service interval is up to 120,000 miles under normal driving conditions. However, if you experience any failure symptoms, you should inspect them sooner.
Is replacing the spark plugs a difficult DIY job?
For the 2016 Scion iM, this is a relatively easy job that most DIYers can complete in under an hour. The spark plugs are easily accessible on top of the engine. 🎬 Follow this step-by-step guide to replace your Scion iM plugs. You will need a 10mm socket, a 14mm deep spark plug socket, a ratchet, and an extension.
🎬 See how to change plugs on the similar 2ZR engine.Should I use anti-seize on the new spark plugs?
Most modern spark plugs from brands like NGK and Denso have a special metal plating on the threads that prevents seizing. These manufacturers often recommend NOT using additional anti-seize compound, as it can alter the tightening torque and potentially cause damage. Always follow the specific instructions from the spark plug manufacturer.
Do I need to gap the new spark plugs?
Most iridium spark plugs for the Scion iM come pre-gapped from the factory. It is a good practice to verify the gap with a feeler gauge, but you should not attempt to adjust the gap on fine-wire iridium plugs, as the delicate electrode can be easily damaged.
What is the OEM spark plug for my Scion iM?
The genuine OEM part number is 90919-01275. This corresponds to a Denso SC16HR11 or an equivalent NGK Laser Iridium plug.
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Technical Specifications
OEM Part Numbers: 90919-01275 90919-01253
Socket Size: 14mm, Thread Reach: 26.5mm, Thread Diameter: 12mm, Recommended Gap: 0.044" (1.1mm)
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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.
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