Do all four ignition coils need to be replaced together?
3 Answers
All four ignition coils need to be replaced together. The core components of the ignition system are the ignition coils and switching devices. By increasing the energy of the ignition coils, the spark plugs can generate sparks with sufficient energy, which is a fundamental requirement for the ignition system to adapt to the operation of modern engines. Below are the steps for removing and installing ignition coils: 1. Open the ignition coil cover on top of the engine; 2. Use a pentagonal wrench to remove the ignition coil mounting screws; 3. Disconnect the ignition coil power plug; 4. Gently pry up the ignition coil with a screwdriver and remove it; 5. Install the new ignition coil and tighten the screws; 6. After connecting the power plug, replace the top cover.
I just replaced one of the ignition coils, but soon after, another one failed. Going through the process twice ended up costing more time and money. A friend at the repair shop told me that these coils usually age at a similar rate—if one fails, the others are likely to follow soon, especially in cars with over 100,000 kilometers. While the lifespan of coils varies by brand, replacing the entire set can prevent repeated removal and installation of the engine cover. If the budget allows, it’s advisable to replace the whole set to ensure more stable ignition system performance and avoid multiple repairs down the line. After all, newer coils are designed to work together, and mixing old and new ones can negatively affect engine performance.
My old Volkswagen has been running for eight years. Last time, one ignition coil failed, and I only replaced the single one. However, the engine light came on again two weeks later. The mechanic suggested that in most cases, it's advisable to replace all four coils because the wear on the old ones tends to be similar. But it also depends on the specific situation: if it's a new car within two years, replacing just the faulty one is fine; if the coil is visibly corroded or deformed, it's better to replace the whole set. Normally, if you notice severe idle vibration while driving, it's time to check the coils—they affect the efficiency of the entire ignition system. After replacing the full set, you'll clearly feel smoother throttle response.
