Why does the BMW 116 experience intermittent idling vibration?
3 Answers
BMW 116 intermittent idling vibration may be caused by severe engine carbon deposits or ignition system issues. 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 deposit inside the engine, the gasoline sprayed by the cold-start injector will be 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 after the carbon deposits have absorbed enough gasoline to reach saturation. After starting, the gasoline adsorbed on the carbon deposits will be drawn into the combustion chamber by the engine's vacuum suction, making the air-fuel mixture too rich. This fluctuation between lean and rich mixtures causes idling vibration after a cold start. The lower the temperature, the more fuel is required for cold starts, and the presence of carbon deposits will significantly affect whether the cold start proceeds smoothly. Ignition system issues: Check the working condition of the spark plugs, high-voltage wires, and ignition coils. Poor performance of the ignition system or inadequate spark plug firing can also lead to such fault symptoms.
I've noticed intermittent shaking at idle in my BMW 116, which has happened several times—it feels like the car is shuddering. This could be due to aging spark plugs or excessive carbon buildup causing uneven ignition, or if the fuel injectors are dirty, the fuel spray might not be accurate. Worn engine mounts with poor damping can also worsen the shaking. Additionally, faulty sensors like the mass airflow sensor can lead to unstable idle. When checking, see if the engine warning light is on; if it is, there might be a trouble code. Last time I had severe shaking, replacing the spark plugs fixed it. I recommend not delaying and taking it to a professional shop for inspection—small issues can turn into costly and dangerous problems if ignored. Regular maintenance, including carbon cleaning and replacing wear-prone parts, can help prevent shaking.
When I'm stopped at a red light in my BMW 116, I always feel irregular vibrations from the car, which is quite annoying. This could be caused by unstable idling, such as excessive spark plug gaps or issues with the ignition coil affecting combustion. Clogged fuel injectors causing uneven fuel distribution can also worsen the vibrations. If the engine mounts are damaged, there's no cushioning left, leading to intermittent severe shaking. If left unaddressed, you might experience uneven acceleration and even increased fuel consumption. I've encountered a similar situation before, and cleaning the throttle body fixed it. I recommend starting with simple checks, like listening for engine stability, before considering a professional diagnosis at a shop. Safety first—don't take it lightly.
