Does Engine Misfire Require Overhaul?
3 Answers
Engine misfire does not require an overhaul. Below are the causes and solutions for engine misfire: 1. The spark plug in the ignition system may be eroded and fail to spark, the high-voltage coil could be damaged and unable to generate high voltage, the high-voltage coil relay might be faulty, or the ECU may malfunction, preventing the high-voltage coil from firing. Repair Method: Replace the spark plug promptly according to the maintenance manual. Use a multimeter to check if the resistance value of the high-voltage coil is normal. Test the relay with a multimeter or listen for a "click" sound during ignition; if present, it indicates normal function, otherwise, it may be damaged. For ECU inspection, visit a 4S shop to use a professional diagnostic scanner. 2. The fuel injection system may have insufficient fuel pressure, damaged fuel lines, excessive wear of the fuel tank pump, clogged fuel filter, inadequate pressure from the high-pressure fuel pump, clogged or poorly atomizing fuel injectors, or excessive wear of the injector needle, leading to fuel dripping and causing excessive gasoline vapor in the cylinder, which wets the spark plug and prevents it from sparking. Repair Method: Use a fuel pressure gauge to check if the fuel line pressure is adequate. Lift the vehicle to inspect the fuel lines for leaks or damage. Replace the fuel filter and check the fuel tank pump and high-pressure fuel pump for excessive wear, replacing them if necessary. Clean or replace the fuel injectors based on their condition.
I've encountered the issue of engine misfiring several times over the years of driving. Misfiring means one of the engine's cylinders isn't working, causing the car to shake, lose power, and fuel consumption to spike. I remember one time when my car misfired on the highway—stepping on the gas pedal was a struggle. Later, the mechanic found that the spark plug had aged and burned out. After replacing it with a new one, which only cost a few hundred bucks, the car ran smoothly again. There's no need for a major repair unless there's serious internal damage like a broken piston or valve. The engine structure is quite complex, but most misfiring issues stem from minor problems like faulty spark plugs, clogged fuel lines, or electrical shorts. It's best to get it diagnosed at a repair shop early on to prevent minor issues from turning into major, costly headaches. In short, don't rush into a major repair—first, identify the root cause.
As an average car owner, I believe engine misfires depend on the specific situation. My car once had a misfire issue—it felt strange when driving, and the check engine light came on. At the repair shop, the mechanic said it might be due to faulty spark plugs or a fuel pump issue, and a simple part replacement could fix it. The cost wasn't high, just about one or two days' wages. A major overhaul is only considered when internal engine components are cracked or severely worn, which would require disassembling the engine for repairs, costing thousands or more. Regular maintenance like oil changes and fuel injector cleaning can prevent misfires—don’t wait for it to worsen. If the car suddenly shakes violently while driving, take it to a reliable shop to check the error codes to avoid compromising driving safety or emissions compliance.
