What is the spark plug gap on a 3.7 Acura?
The factory spark plug gap for the 3.7-liter Acura V6 is 0.043 inches (1.1 mm).
The 3.7L V6 engine family, used in models such as the Acura MDX and certain sedans, relies on a precise spark plug gap to ensure reliable starts, smooth idling, and good fuel economy. While 0.043 in (1.1 mm) is the common factory target for OEM iridium plugs, actual gap requirements can vary slightly depending on the plug type and heat range. Always confirm the exact specification for your specific model year and plug choice in the official service data or owner's manual.
Official gap specification for the 3.7L Acura
The following specification reflects the typical target gap used with OEM-grade iridium plugs on the 3.7L V6 family and is a useful reference for most servicing scenarios.
- Gap: 0.043 inches (1.1 millimeters) for factory/OEM iridium plugs. If you use aftermarket plugs, always verify their recommended gap and adjust to match the plug maker’s specification.
Sticking to the factory gap helps preserve ignition performance, emission standards, and fuel economy. If you’re installing plugs that specify a different gap, follow those instructions and recheck the gap after installation.
Using aftermarket plugs or different heat ranges
If you opt for aftermarket plugs (copper, platinum, or different heat ranges) the gap can vary. Always check the plug manufacturer’s recommended gap and adjust accordingly, since some plugs may call for a slightly different setting than the OEM spec.
Before the list, here is a practical guide to verify and set the gap when using non-OEM plugs.
- Remove the spark plug and inspect it for wear or damage. Do not reuse damaged plugs.
- Measure the gap with a precise feeler gauge, aiming for 0.043 inches (1.1 mm) unless the plug maker specifies otherwise.
- If the gap is off, carefully adjust by filing or using the correct gapping tool. Do not bend the center electrode or apply excessive force.
- Reinstall the plugs to the manufacturer’s torque specification and double-check the gap after installation.
Following these steps helps ensure reliable ignition performance when using plugs that differ from the OEM specification. If in doubt, consult the plug manufacturer’s data and your vehicle’s service manual for torque and seating guidance.
Common questions about 3.7L spark plug gaps
Common signs of an incorrect gap include rough idle, misfires, reduced fuel economy, and difficult starting. If you experience any of these issues after replacing plugs, re-check the gap and consider re-inspecting the ignition system as a whole.
Summary
For the 3.7-liter Acura V6, the usual target gap is 0.043 inches (1.1 mm) for OEM plugs. When using aftermarket plugs, always follow the plug manufacturer’s recommended gap and verify it with a precise feeler gauge. After installation, recheck the gap and refer to the vehicle’s service manual for the correct torque and seating procedure. Proper gap maintenance helps ensure optimal ignition performance, fuel efficiency, and engine reliability.
