What is the spark plug gap on a 4.3 Chevy motor?
The spark plug gap for a common Chevy 4.3L V6 is typically 0.060 inches (1.52 mm).
This baseline applies to most stock configurations using standard copper plugs. The gap can vary if you’re using different plug types or tuning, so always verify with the plug manufacturer’s specification and the GM service data for your exact vehicle.
Baseline gap for the 4.3L V6
In most factory and aftermarket setups intended for everyday driving, the recommended gap is commonly 0.060 inches (1.52 mm). Below are general notes you should keep in mind when selecting or inspecting plugs.
- 0.060 inches (1.52 mm) is the standard baseline gap for the 4.3L V6 in many stock configurations with conventional plugs.
- Some aftermarket long-life plugs or iridium/platinum variants may come pre-gapped differently; if so, adjust to the plug manufacturer’s recommended gap and verify it matches the vehicle’s requirements.
Bottom line: start with 0.060 inches as the default and only deviate if the plug packaging or service manual specifies a different gap for your particular setup.
How to check and adjust the gap
To ensure proper ignition and performance, follow these steps to measure and adjust the gap accurately.
- Gather tools: a spark plug socket, torque wrench, and a feeler gauge appropriate for a 0.060 inch gap (1.52 mm).
- Remove the spark plug, inspect the plug for wear or damage, and wipe away any debris from the seat area.
- Measure the gap with the feeler gauge. If the gap is not 0.060 inches (1.52 mm), carefully adjust the ground electrode by lightly bending it to widen or narrow the gap. Do not force or twist the electrode beyond gentle correction.
- Reinstall the plug and torque to the manufacturer’s specification for your engine (check the GM service manual or the plug packaging for the exact torque). Over-tightening can damage the cylinder head threads; under-tightening can cause misfires or fuel leaks.
- After all plugs are installed, run the engine to verify proper operation and recheck gaps if you notice any misfires or performance issues.
Always follow the exact specifications from your vehicle’s service data and the spark plug manufacturer, especially if you’re using a plug type different from the stock recommendation.
Summary
The standard spark plug gap for most Chevy 4.3L V6 engines is 0.060 inches (1.52 mm). Use this as your baseline, but always confirm with the specific plug’s instructions and the GM service manual for your model year. When installing plugs, measure accurately, adjust gently, and torque to spec to ensure reliable ignition and optimal 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.
Do I need to gap my AC Delco spark plugs?
NOTE: ACDelco GM OE Iridium Spark Plugs are pre-gapped during manufacturing. Never attempt to gap an ACDelco GM OE Iridium Spark Plug. You could damage the spark plug.
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
