What Causes Engine Vibration in Audi Q5?
4 Answers
1. Severe Engine Carbon Deposits: The most common cause of car vibration is a dirty throttle body or excessive carbon buildup in the fuel injectors. When there is too much carbon buildup inside the engine, the gasoline sprayed by the cold-start injector is largely absorbed by the carbon deposits, resulting in an overly lean air-fuel mixture during cold starts and making ignition difficult. In this situation, the engine will only start easily once the carbon deposits have absorbed enough gasoline to reach saturation. After ignition, the gasoline adsorbed on the carbon deposits is sucked into the combustion chamber by the engine's vacuum, making the air-fuel mixture overly rich. The constantly fluctuating air-fuel mixture causes idle vibration after a cold start. The lower the temperature, the more fuel is required for a cold start, and the presence of carbon deposits significantly affects the smoothness of the cold start. 2. Ignition System Issues: Check the condition of the spark plugs, high-voltage wires, and ignition coils. Poor performance in the ignition system or weak sparking from the spark plugs can also lead to such symptoms. 3. Unstable Fuel Pressure: If you have already cleaned the engine carbon deposits, throttle body, replaced gaskets and spark plugs, but still experience body vibration at idle, it is recommended to visit a 4S shop to check the fuel supply pressure and the intake pressure sensor. Abnormal fuel pump pressure or incorrect readings/malfunctioning of the intake pressure sensor can cause body vibration. 4. Aging Engine Components: Car vibration can also be related to aging engine mounts (also known as engine mounts). Engine mounts act as the shock absorption system for the engine, absorbing minor vibrations during operation. If the engine mounts are faulty, these vibrations will transfer to the steering wheel and the cabin, causing vibration at idle.
I've been repairing cars for many years, and engine shaking in the Audi Q5 is quite common. First, you need to check the ignition system. For example, aging spark plugs or those clogged with carbon deposits, or faulty ignition coils can cause misfires, leading to noticeable vibrations. The fuel system should not be overlooked either. Clogged fuel injectors or insufficient fuel pump pressure can make the engine run unevenly. On the intake side, a dirty mass airflow sensor or leaks in the intake pipe can affect the air-fuel ratio. Then there are the mechanical components. Damaged engine mounts can make the shaking more pronounced, and misaligned timing belts can also cause issues. Lastly, problems in the electrical system, such as ECU faults or damaged oxygen sensors, can disrupt engine control. It's advisable not to tinker with it yourself. Regular maintenance, checking for carbon buildup, and replacing old components can prevent problems. If the issue is severe, take it to a professional shop immediately.
My family owns an Audi Q5, and a while ago, it also experienced engine shaking, driving like a sieve. A friend said the common reason is that the spark plugs needed replacing. I tried checking it myself but didn’t understand much, so I took it to the repair shop and found out the ignition coil was burnt out—replacing it fixed the issue. Another time, the shaking was due to a fuel system problem caused by excessive carbon buildup in the fuel injectors. Another neighbor’s Q5 had shaking due to loose engine mounts, and the vibrations transmitted into the cabin were very annoying. Remember not to ignore small abnormalities; timely diagnosis might cost a bit but saves major trouble. Also, poor fuel quality or a dirty air filter can be contributing factors. Using high-quality fuel and regularly cleaning the filter can prevent many issues.
Engine shaking is commonly caused by ignition failures, spark plug carbon buildup or misfires, and faulty ignition coils that may cause a cylinder to stop working. Issues in the fuel system, such as clogged fuel injectors, can lead to insufficient fuel supply. A dirty mass airflow sensor can disrupt the balance of air intake. Additionally, ECU control errors or incorrect sensor signals may also cause instability. Regular carbon cleaning and component inspections can help reduce the likelihood of these issues.
