It is generally not recommended to use a standard coin to gap spark plugs because it can be inaccurate and potentially damage the spark plug electrodes, especially those made with precious metals. Coin-style spark plug gap tools are available that are designed specifically for this purpose and offer a safer, more accurate way to measure and adjust the gap.
Here’s a breakdown of how to use a coin-style spark plug gap tool, and the reasons why a standard coin is not ideal:
- Determine the correct gap: Consult your vehicle’s owner’s manual or a reliable source (like a parts store or reputable online guide) to find the recommended spark plug gap for your specific vehicle and spark plug type.
- Measure the existing gap: Insert the thinnest part of the coin-style tool between the center and ground electrodes of the spark plug. Gently slide the tool along the ramp until you feel slight resistance. The marking on the tool where it stops indicates the current gap.
- Adjusting the gap:
– To widen the gap: If the gap is too narrow, use the drilled hole in the coin tool. Hook the ground electrode onto the rim inside the hole and gently pry upwards, taking care not to touch the center electrode or porcelain.
– To narrow the gap: If the gap is too wide, gently tap the side of the plug (where the ground electrode is) against a hard, flat surface. Be very gentle to avoid damaging the plug.
- Recheck the gap: After each adjustment, remeasure the gap to ensure it is within the recommended specifications. Make small, incremental adjustments and recheck frequently to avoid over-bending the ground electrode.
- Inaccuracy: A standard coin does not have the precise markings or tapered design of a proper gap tool, making accurate measurement difficult.
- Damage to electrodes: Precious metal spark plugs (iridium, platinum, ruthenium) are more fragile. Using a coin or other improvised tool can easily damage or break the delicate center electrode or scrape off the protective coating, which can affect the spark plug’s performance and lifespan.
- Always refer to your vehicle’s specifications for the recommended spark plug gap.
- For precious metal spark plugs (iridium, platinum, ruthenium), it’s highly recommended to use a wire-type or feeler gauge for a safer and more accurate gap adjustment.
- Even with pre-gapped spark plugs, it’s wise to verify the gap before installation.
- Be gentle when adjusting the electrode and avoid forcing the gapping tool.
Can I use a coin to gap spark plugs?
Using a Feeler Gauge or Wire-Type Gap Gauge
While a coin-style tool can be used in a pinch, albeit cautiously, it is far too easy to damage the iridium or platinum metals, which decreases the lifespan of the plug.
How to correctly gap a spark plug?
Thanks for asking. And then on the back is millimeters. Now in order to gap this you need to figure out where it’s at right. Now. So right now I’m sliding it on here. And once you start to feel resistance.
Can I use a dime to gap spark plugs?
From my experience, But in case you don’t have any spark plug gap tool on hand, here’s how you can achieve the correct gap. Things you’ll need: Manufacturer’s manual. Coins (penny, dime)