Can a Spark Plug with Cracked Ceramic Be Used?

[RobertLee]

Spark plugs with cracked ceramic cannot be used. The functions of a spark plug are: 1. To introduce the high-voltage electricity generated by the ignition coil into the engine cylinder; 2. To generate a spark between the spark plug electrode gaps to ignite the air-fuel mixture, ensuring the engine operates normally. The working principle of a spark plug is: under the control of the engine, it introduces the high-voltage electricity generated by the ignition coil into the engine cylinder, creating a spark between the spark plug electrode gaps to ignite the mixed gas, enabling the engine to run smoothly. Types of spark plugs include: 1. Standard spark plugs; 2. Insulator projection spark plugs; 3. Electrode spark plugs; 4. Seat spark plugs; 5. Pole spark plugs; 6. Surface gap spark plugs.

[VanAliyah]

Last time when I got my car repaired, the mechanic told me that cracked ceramic parts on spark plugs should never be used as a temporary fix. The ceramic acts like a protective shield, and if it cracks, the center electrode gets exposed. At best, the engine will start shaking and fuel consumption will skyrocket; at worst, high-voltage arcs could scatter and damage the ignition coil. My neighbor tried pushing through with a cracked one and ended up with a roadside fire and breakdown, costing him 2000 bucks to replace the entire ignition system. A small crack might let you drive for a while, but it's best to check immediately whether it got damaged during an oil change or if it's a counterfeit part. Nowadays, a set of NGK spark plugs only costs around a hundred bucks—way cheaper than a tow truck fee.

[Stephanie]

As someone with ten years of auto repair experience, I can tell you straight: a cracked insulator is a death sentence! The spark plug's center electrode carries 20,000-30,000 volts, and cracks will cause immediate current leakage, significantly reducing ignition energy. The engine misfire hesitation when you step on the gas becomes particularly noticeable. Last week, we removed cracked spark plugs in the shop - their ceramics had shattered into fragments stuck inside the ignition coils. Remember to have a professional mechanic use magnetic sockets during removal/installation; pulling forcefully yourself may leave ceramic fragments inside the cylinder head. Additionally, ceramic cracks mostly occur due to uneven thermal expansion/contraction, especially common after -30°C temperatures in northern regions.

[VonElla]

A lesson from my car enthusiast group: If the ceramic cracks, turn off the engine immediately! Cases of ignition coils being punctured by electric arcs on the highway have even made the news. Spark plugs operate in a high-temperature environment of 900°C, and cracks can rapidly expand. Last time, a group member replaced theirs with aftermarket parts, and cracks appeared within two months—there's a reason OEM parts can last 60,000 kilometers. A reminder to everyone: Pay attention to the heat range parameters when purchasing, and don’t just go for the cheapest option. In an emergency, you can drive to a repair shop, but don’t exceed 40 km/h, and listen for any backfiring sounds from the exhaust.

[AngelaLee]

Modification enthusiasts' real-world test: Cracked ceramics can cause at least a 10% horsepower drop. Inspection with a borescope revealed that cracks lead to premature ion leakage and ignition timing disorder. During track days, we've witnessed the tragedy of cracked ceramic spark plug electrodes melting and sticking to cylinder heads. It's recommended to use a torque wrench for installation (20Nm for platinum cores), as over-tightening can crush the ceramic. Turbocharged modified cars especially require frequent checks, with disassembly inspection every 10,000km being essential. I've kept all the cracked ceramic plugs I've replaced as cautionary examples.