What is the spark plug gap for a 4.3 V6?
Typically 0.060 inches (1.5 mm) gap. Exact specs vary by year and plug type; verify with your owner's manual or the plug packaging for your specific vehicle.
Understanding the 4.3 V6 and why gap matters
The 4.3-liter V6 used in GM trucks and vans is a two-valve-per-cylinder design that relies on a precise spark to ignite the air-fuel mixture. The gap affects ignition energy, combustion efficiency, and cold-start performance. Too small a gap can weaken the spark and hamper performance; too large a gap can cause misfires and starting trouble.
Standard spec and what to check
For the vast majority of 4.3L V6 engines, the recommended spark plug gap is 0.060 inches (1.5 mm). This applies to many copper-core, platinum, and iridium plugs used in these engines. However, some model-year variants or plug types may differ, so always confirm the exact spec for your vehicle.
Before you install new plugs, verify the gap with a feeler gauge and ensure that any pre-gapped plugs are within a tight tolerance of 0.060 inches.
To help you prepare, here is a quick checklist for setting the gap correctly:
- Identify the exact 4.3L V6 variant (model year and vehicle) and the spark plug type you plan to use.
- Check the plug's specified gap; for most 4.3L engines this is 0.060 in (1.5 mm).
- Gap the plugs using a proper spark plug gap tool, bending the ground electrode only as needed and evenly.
- Torque the plugs to the manufacturer's specification when installing.
Concluding guidance after the checklist: Always re-check the gap after any handling or cleaning of the plug and before installation to avoid misfires and ensure reliable ignition.
Notes on variations
Some older or specialized 4.3L engines may require slightly different gaps or specific plug types. If your owner's manual, service manual, or the spark plug packaging lists a different gap, follow that specification. When in doubt, consult a dealership or a qualified mechanic with your VIN in hand.
Summary
For most GM 4.3L V6 engines, the standard spark plug gap is 0.060 inches (1.5 mm). Always verify the exact spec for your year, model, and plug type, and gap the plugs with a proper tool before installation to ensure reliable ignition and optimal engine performance.
What spark plugs does the 2004 Silverado 4.3 use?
ACDelco GM Original Equipment Iridium Spark Plug 41-993.
How to know the correct spark plug gap?
Measure the existing gap of the spark plug. Using your gap gauge or feeler gauge, run the tool through the electrodes to determine the measurement. Take note of the measurement and compare it to the recommended setting listed in the owner's manual.
What is the spark plug gap on a 4.3 Chevy?
The recommended spark plug gap for a Chevy 4.3L engine is typically 0.060 inches (1.52 mm1.52 mm1.52 mm) for earlier models, but the specification can vary, with some later versions requiring a smaller gap such as 0.035 inches (0.89 mm0.89 mm0.89 mm) or 0.040 inches (1.02 mm1.02 mm1.02 mm). Always verify the correct gap for your specific vehicle year and model to ensure optimal performance and avoid misfires.
This video demonstrates how to check the spark plug gap on a Chevy 4.3L V6 Vortec engine: 1mSecond Hand SpeedYouTube · Apr 7, 2023
Important considerations
- Check your specific vehicle's manual: It is crucial to consult your owner's manual or a service manual for the precise gap specification for your year and model.
- Adjust for different years: While some earlier 4.3L engines with Vortec heads used a 0.060" gap, later models were updated and may require a smaller gap such as 0.040".
- Use a feeler gauge: Use a proper feeler gauge to check and set the gap before installation to ensure it's set correctly.
- Do not gap certain plugs: Do not attempt to gap modern iridium or platinum spark plugs, as this can damage them. If the gap is incorrect out of the box, replace the plugs with a new set that has the correct gap.
You can watch this video to learn how to check the spark plug gap on a Chevrolet 4.3L V6 engine: 59sThe Enthusiast MechanicYouTube · Mar 18, 2022
What is the spark plug gap on a 4.3 OMC?
The correct gap for the plugs is . 035".
