What Causes BMW's Air Leak and Unstable Idle?
1 Answers
BMW's air leak and unstable idle reasons introduction: 1. Engine carbon deposits: The most common cause of car shaking is a dirty throttle body or excessive carbon deposits 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, making it difficult to start. In this situation, the car will only start easily once the carbon deposits have absorbed enough gasoline to reach saturation. 2. Ignition system issues: Check the condition of the spark plugs, high-voltage wires, and ignition coils. Poor performance of the ignition system or weak sparking from the spark plugs can also lead to such symptoms. 3. Unstable fuel pressure: Have the fuel supply pressure and the intake pressure sensor checked at a 4S shop. If the fuel pump's supply pressure is abnormal or the intake pressure sensor's readings are incorrect or malfunctioning, it can cause the car body to shake. 4. Aging engine mounts (also known as engine cushions): Engine mounts are essentially the shock absorption system for the engine. They absorb the minor vibrations produced during engine operation. If the engine mounts are faulty, these vibrations will be transmitted to the steering wheel and the interior of the car, causing shaking during idle.
