Why does the Audi A6 idle shake?
2 Answers
The following are the specific reasons for the Audi A6 idle shake: 1. Shock absorber system failure: The shock absorber system is mainly responsible for filtering the vibration of the engine during operation. If there is a problem with the shock absorber, these vibrations will be directly transmitted to the steering wheel and the interior of the car, affecting driving. When the engine is idling, turning on the electrical system in the car can also easily cause shaking. The engine increases the load due to the activation of electrical appliances, causing the idle speed to drop. To compensate for the shaking caused by the idle speed drop, the engine will automatically increase the speed. 2. Unstable oil pressure: Check whether the fuel supply pressure and the intake pressure sensor are normal. If the fuel pump supply pressure is abnormal or the intake pressure sensor value is incorrect or not working properly, it will cause the car body to shake. 3. Cold start: The main reason for the car body shaking during a cold start is insufficient fuel combustion, resulting in insufficient power of the car. The ignition energy is low. When starting, when the temperature of the fuel and lubricating oil is low, it is necessary to rely on more fuel to meet the power demand. Over time, the gap between the poles of the spark plug will gradually increase, resulting in a decrease in ignition energy and poor fuel atomization, thereby causing the car body to shake. In addition, aging of the ignition coil, aging or leakage of the high-voltage line of the spark plug will also lead to a decrease in ignition energy.
As a long-time Audi A6 owner, I've experienced several instances of idle vibration issues. Typically, this is due to problems in the ignition system, such as aging spark plugs after 40,000-50,000 kilometers causing unstable ignition, or faulty ignition coils leading to incomplete combustion. Another common cause is severe carbon buildup in the engine, which affects air intake efficiency and results in uneven engine RPM. I remember one severe vibration incident where the mechanic found a heavily clogged air filter and carbon deposits in the throttle body - cleaning these components resolved the issue. Additionally, worn engine mounts are a frequent culprit; the rubber support components in Audi models tend to deform over time, amplifying vibrations. It's crucial not to ignore these symptoms long-term, as they can increase engine wear, raise fuel consumption, and even affect chassis balance. I recommend checking spark plugs and cleaning the throttle body every 20,000 kilometers, and seeking professional diagnosis at the first sign of vibration to prevent minor issues from escalating into major repairs.
