What is the best way to clean spark plugs?

[VanSteven]

Spark plugs are best cleaned using carburetor cleaner. Carburetor cleaner is specifically designed for removing oil, grease, and carbon deposits, effectively cleaning carbon buildup without damaging the spark plugs. Spark plugs can also be cleaned with white vinegar, carburetor cleaner, or toilet cleaner. The cleaning methods for spark plugs are as follows: 1. White vinegar: Place the spark plug in a glass container, pour white vinegar until it covers the spark plug, soak for 2 to 3 hours, then scrub clean with a stiff toothbrush and let it air dry. 2. Carburetor cleaner: Place the spark plug head-down in a glass bottle, spray carburetor cleaner into the bottle until the spark plug is submerged, cover the bottle, wait for about half an hour, then remove it, scrub clean with a toothbrush, and let it air dry or use a hair dryer to dry it. 3. Toilet cleaner: Soak the spark plug's ignition electrode directly in pure toilet cleaner, place it in a ventilated environment for 10 minutes, remove it when the bubbles gradually decrease, rinse with white vinegar, and let it air dry.

[ClaireDella]

From my over ten years of driving experience, cleaning spark plugs requires some finesse. Never use sandpaper to scrub them roughly just to save time, as that can easily damage the electrodes. I prefer to first spray them with carburetor cleaner to dissolve carbon deposits, then gently brush the ceramic body and electrode gaps with a fine brass wire brush. After cleaning, they must be thoroughly dried, and any residue should be blown away with compressed air. If there's oil on the spark plug threads, dip a bit of kerosene and wipe it off slowly. Cleaning can temporarily solve problems, but it significantly reduces lifespan. Old spark plugs with over 60,000 kilometers won't last long even after cleaning, so it's better to replace them. Keep your hands steady during cleaning to avoid deforming the electrodes, which would render them completely useless.

[DiLyla]

Cleaning spark plugs yourself really tests your patience. My go-to method is soaking plus brushing. After removing the spark plugs, soak them in carburetor cleaner for 20 minutes—the carbon deposits will float up. Then gently brush along the electrode texture with a toothbrush, and use an old toothpick to clean the grooves in the threaded part. Avoid using vinegar or cola, as the acidic substances can corrode the metal. After cleaning, thoroughly dry them with a paper towel, then use a hair dryer on low heat to dry them for half an hour. I keep a feeler gauge in my car—after cleaning, you must check if the 0.8mm gap meets the standard. Although cleaning can save you a hundred bucks or so, they’ll need replacing again after another 5,000 kilometers at most. In the end, it’s more hassle-free to just replace them with new ones.

[OMicah]

In repair shops, we often see cases where customers damage their spark plugs by improper cleaning. From a professional standpoint, platinum or iridium spark plugs should never be cleaned, as the electrode coating can be easily damaged. For standard nickel alloy spark plugs, you can try using a specialized foam cleaner—spray it on and let it sit for five minutes to soften the carbon deposits. Avoid any physical scrubbing during cleaning; even brushes should be soft nylon ones. Post-cleaning ignition testing is crucial; stop using the plug immediately if any cylinder misfire is detected. Honestly, the cost of cleaning plus labor is only about 30 yuan less than buying new spark plugs. It's better to inspect and replace them every 20,000 kilometers to ensure the engine stays in optimal condition.

[EmersonRose]

I've tried various money-saving cleaning tips and found that carburetor cleaner plus a toothbrush works best. Always take photos to record the electrode positions before cleaning to avoid incorrect reassembly. Brush gently as if dusting antiques, focusing on removing carbon deposits from the inner side of the side electrode. Once I got lazy and installed them without proper drying, resulting in severe engine vibration during cold starts. Now I leave them on the balcony to dry for at least three hours to ensure complete dryness. Spark plugs cleaned this way will consume about 0.5L more fuel than new ones, so I recommend using them only as temporary solutions. Considering labor and cleaner costs, it's more economical to stock up on new spark plugs during e-commerce promotions.

[MacHarper]

Last time at the tuning shop, I saw spark plugs being cleaned with ultrasonic waves, and the results were truly impressive. Putting the spark plugs into the cleaning machine, a neutral solution vibrates at high frequency for ten minutes, even shaking out stubborn carbon deposits from the gaps in the ceramic body. However, timing must be carefully controlled; exceeding half an hour may damage the insulation layer. For regular car owners, using carburetor cleaner is sufficient, but it's essential to choose one without acetone, otherwise, the rubber seals may deteriorate. After cleaning, it's necessary to check if the center electrode is properly aligned; if it's off-center, it needs to be replaced. In reality, no matter which cleaning method is used, it can only restore about 70-80% of performance, and there may be a risk of knocking during aggressive driving.