How many ignition coils should be replaced at once?
3 Answers
How many ignition coils should be replaced at once depends on the situation: 1. If the ignition coil needs to be replaced due to natural aging failure, and only one has failed, but the others may also be nearing the end of their lifespan, all four should be replaced together; 2. If the ignition coils have not been used for long and one or two have failed while the others are still functioning properly, only the faulty ignition coils need to be replaced. Symptoms of a damaged ignition coil include: decreased engine power, increased fuel consumption, leading to engine misfire. Reasons why ignition coils are prone to damage include: 1. Excessive power generation, causing the ignition coil to be overloaded; 2. Excessive spark plug gap; 3. Poor quality gasoline; 4. Incorrect cylinder compression ratio; 5. Program failure in the computer board.
Having driven for over a decade, when encountering ignition coil issues, I usually recommend replacing the entire set at once. For instance, if the car has a four-cylinder engine, it's best to replace all four coils. Why is that? Ignition coils gradually wear out with use and have similar lifespans. If only the faulty one is replaced, the remaining old coils may fail soon, leading to unstable engine operation, severe shaking, increased fuel consumption, and even damage to other components like spark plugs. Last year, I replaced just one coil, only for another to burn out two months later, resulting in an unnecessary extra trip to the repair shop and additional time and money spent. Although replacing all coils at once has a higher initial cost, it saves hassle and ensures a balanced ignition system. I recommend purchasing OEM or compatible parts to avoid installation issues, keeping your car running smoothly.
From a practical standpoint, ignition coil replacement should be done as a complete set. Replace as many coils as there are cylinders in the car. Keeping some old ones can lead to uneven ignition efficiency, potentially causing engine vibration or performance degradation. I've seen numerous cases where partial replacements resulted in recurring issues within days, with car owners blaming repair shops. The correct procedure is to first diagnose the faulty coil, then replace the entire set to prevent remaining coils from dragging down performance due to aging. Additionally, inspect related wiring for damage or looseness—this is crucial for preventing future failures. Remember, investing in a full replacement upfront is wiser than piecemeal fixes. It protects your engine and reduces unexpected expenses.
