What are the reasons for the Audi A6L engine shaking without reporting a fault?
3 Answers
The reasons for the Audi A6L engine shaking without reporting a fault are: 1. Dirty air filter; 2. Open circuit in the high-voltage line; 3. Abnormal water temperature; 4. Clogged fuel injector; 5. Engine idle speed too low. Taking the 2020 Audi A6L as an example, it belongs to the mid-to-large-sized car category, with body dimensions of: length 5038mm, width 1886mm, height 1475mm, wheelbase 3024mm, and fuel tank capacity 73L. The 2020 Audi A6L features a front suspension with a five-link independent suspension and a rear suspension with a five-link independent suspension. It is equipped with a 2.0L turbocharged engine, with a maximum horsepower of 190PS, maximum power of 140kW, maximum torque of 320Nm, and is paired with a 7-speed dual-clutch transmission.
I frequently repair Audi vehicles, and this kind of engine shaking without triggering a fault code is quite common. The most common issue is with the ignition system, such as aging spark plugs or damaged ignition coils, causing intermittent misfires in a cylinder. Since the engine control unit (ECU) threshold isn't reached, no fault code is triggered. Another common cause is severe carbon buildup, clogged fuel lines or injectors, affecting combustion uniformity. Additionally, intake manifold leaks or minor sensor faults, like unstable signals from the crankshaft position sensor, can also lead to this. Finally, physical causes like loose engine mounts can make the entire body shake, but the computer interprets it as normal vibration. I recommend starting with the simplest solutions: first replace the spark plugs and clean the carbon deposits, then take it to a repair shop for a detailed data stream check with a diagnostic tool to prevent it from worsening into more serious issues.
My A6 also had similar shaking issues after long-term use, without any warning lights on, which was quite annoying. I remember that time it was a fuel system problem—uneven carbon buildup on the fuel injectors causing engine vibration at idle. Sometimes, a dirty air filter or a slight vacuum tube leak can also cause this; it doesn’t affect driving but the shaking is noticeable. Another friend’s car had a bad spark plug, and replacing it fixed the issue. The key is to address it promptly; otherwise, fuel consumption may increase or even damage the engine. Luxury cars like Audi have sensitive sensors, but some minor issues might self-resolve without triggering codes. Don’t worry—you can first check the air filter and whether the fuel grade matches, then consider visiting the dealership to update the system via computer diagnostics.
