The recommended spark plug gap for a 2008 Scion xB is 0.043 inches (1.1 mm).
The 2008 Scion xB typically uses the 2.4-liter 2AZ-FE inline-four engine, and Toyota’s factory guidance for replacement plugs calls for a gap of 0.043 inches (1.1 mm). Different plug types or heat ranges can influence the optimal gap, so always verify with the plug manufacturer’s data and the vehicle’s service manual if you’re using aftermarket parts. This article explains the spec, why it matters, and how to check and adjust the gap correctly.
Engine and gap specification
The second-generation Scion xB, produced around 2008, commonly uses the 2AZ-FE 2.4-liter four-cylinder engine. For standard copper, platinum, or iridium plugs employed with this engine, the official gap specification is 0.043 inches (1.1 mm). Maintaining this gap helps ensure reliable starts, steady idle, and efficient combustion across driving conditions.
What can affect the gap
Although 0.043 inches is the standard, some plugs—especially certain aftermarket options or different heat ranges—may arrive pre-gapped differently. If you install plugs with a different pre-gap, verify that their gap matches the 0.043-inch specification and adjust only as needed using a proper feeler gauge. Always confirm with the plug manufacturer’s guidance if you’re deviating from OEM parts.
How to check and set the spark plug gap
Before you begin, gather a few basic tools: a spark plug socket, a feeler gauge or a dedicated gap tool, and a way to reinstall plugs safely. The steps below describe how to measure and adjust the gap on a typical 2008 xB engine.
- Remove the spark plug boot or coil-on-plug connector from the plug you’re inspecting.
- Carefully thread out the spark plug and inspect for wear or damage on the electrode and insulator.
- Measure the gap with a feeler gauge. If the gap is not 0.043 inches (1.1 mm), gently bend the outer electrode to achieve the correct gap. Do not bend the inner electrode.
- If the plug shows signs of wear or damage beyond the gap, replace it with a new plug that is pre-gapped to the OEM spec or gap the new plug to 0.043 inches before installation.
- Reinstall the plug, ensuring it is seated properly and routed without damaging the threads or insulator. Follow the service manual for torque recommendations if you choose to torque the plugs.
After installing or re-gapping the plugs, start the engine and listen for smooth idle and steady acceleration. If you notice misfires or rough running, recheck the gap and the plug condition, and consider replacing worn components as needed.
Summary
The spark plug gap specification for the 2008 Scion xB is 0.043 inches (1.1 mm) for its typical 2AZ-FE engine. Always verify the gap against the plug manufacturer’s instructions and the vehicle’s service manual, especially when using aftermarket plugs or a different heat range. Correctly gapping the plugs supports reliable starts, clean combustion, and consistent engine performance.