What are the symptoms of a faulty ignition coil in a Jetta?
2 Answers
Here are the symptoms of a faulty ignition coil in a Jetta: 1. When idling, the car body shakes noticeably. Observe the exhaust pipe outlet, and you can see that the exhaust gas flow is intermittent, accompanied by severe shaking of the exhaust pipe and a clear "popping" sound; 2. While driving, when the RPM is below 2500, the car body shakes noticeably with poor acceleration. The shaking disappears once the RPM exceeds 2500; 3. Open the engine hood and observe the running engine. You will notice significant shaking of the engine, which is clearly abnormal compared to the normal operating state of the engine, with a large shaking amplitude.
When I was driving my Jetta, I experienced a faulty ignition coil. It was very difficult to start the car, and I could feel the engine constantly vibrating, as if the whole car was shaking. This was especially noticeable during low-speed driving or when waiting at a red light. Acceleration also became very sluggish—stepping on the gas didn’t translate to power, yet fuel consumption suddenly skyrocketed, burning money like crazy. What’s worse, the check engine light kept coming on, which was really annoying. After inspection, I learned that the ignition coil is responsible for supplying power to the spark plugs. When it fails, it causes misfires in a cylinder, affecting other components. My advice is to address the issue as soon as possible—otherwise, it could damage the catalytic converter or spark plugs. The mechanic told me this problem is common in older Jettas and suggested checking the related wiring every few years to avoid breaking down on the road.
