Worn Chevy spark plugs can trigger rough starts, poor fuel efficiency, and power loss. These small components play a big role in overall engine performance.
At Sarchione Chevrolet of Randolph, we help our customers stay ahead of common maintenance issues that affect engine reliability. If you're shopping for new Chevrolet models or looking to keep your current ride running well, it's important to understand how spark plugs impact your engine.
Spotting Worn Chevy Spark Plugs
Engine misfires are one of the first signs that spark plugs are past their lifespan. Misfires usually happen when one or more plugs fail to fire consistently. Drivers often feel the engine stumble at idle or hesitate during acceleration. These symptoms may not seem urgent at first, but they can cause internal strain and increased emissions over time.
When spark plugs wear down, they no longer provide a steady spark. This affects combustion timing and reduces the engine’s ability to produce clean, consistent power. You might notice sluggish throttle response or an increase in fuel consumption. These changes tend to worsen with mileage, especially if the plugs have exceeded 60,000 miles.
Fouling is another issue that comes with age or poor maintenance. Deposits from oil or carbon build up around the electrodes and block the arc. Once that happens, firing becomes inconsistent and leads to harder starts and increased engine load. If your check engine light comes on, it could be related to this kind of problem.
Replacement Process and Best Practices
Spark plug replacement follows a direct process, but it requires the right tools and access to engine components that may be hard to reach. Many newer models have compact engine bays with minimal clearance. On some vehicles, removing intake parts or engine covers becomes necessary to reach the plug wells.
The replacement process begins by disconnecting the ignition coil or spark plug wire, then removing the plug using a socket. Before installing the new plug, it’s critical to check the gap and apply anti-seize compound if recommended by the manufacturer. Over-torquing the plug can damage the threads or crack the cylinder head, which leads to costly repairs.
Heat cycling causes spark plugs to expand and contract, which puts pressure on the threads and seal. That’s why technicians replace plugs with precise torque values to maintain integrity and prevent leaks. After installation, the ignition coil or wire gets reconnected and tested under idle and light acceleration to confirm smooth operation.
Timing and Maintenance Schedules
Manufacturers set spark plug intervals based on materials and expected engine performance. For most Chevrolet models, platinum or iridium plugs last between 60,000 and 100,000 miles. These longer-lasting metals help maintain spark strength over time and reduce wear from heat and combustion gases.
Maintenance schedules also depend on engine design and driving habits. Frequent short trips or extended idling create cooler engine temperatures that allow deposits to form faster. Aggressive driving adds heat stress and shortens the life of ignition components. Both conditions require more frequent inspections, especially if performance changes suddenly.
You should not wait for symptoms to show. A visual inspection during regular service appointments helps spot problems early. If there’s visible wear, chipping, or carbon buildup, it’s time to replace the plugs before they affect other engine components.
Worn spark plugs can create a range of performance problems that affect drivability and fuel economy. Staying on top of plug replacement ensures your engine runs optimally. At Sarchione Chevrolet of Randolph, we help drivers protect their investment with expert service and parts support. If you're due for maintenance, you can schedule a service with our trained technicians, who are familiar with your vehicle inside and out.