What Causes a BMW to Shudder When Accelerating?
2 Answers
BMW cars may shudder when accelerating due to deformed half-shafts, degraded spark plugs, or the use of low-quality gasoline. Deformed Half-Shaft: Over time, the half-shafts of a car can bend, twist, break, or experience wear on the spline teeth due to long-term torsional fatigue and impact forces. This can cause the car to shudder rhythmically when accelerating within a certain speed range. The shuddering stops when the accelerator is released. Degraded Spark Plugs: If the spark plugs are degraded or of poor quality, the car may experience weak acceleration or shuddering during acceleration. In such cases, the spark plugs need to be replaced. Low-Quality Gasoline: Using low-quality gasoline can cause the engine to shudder. If there is excessive carbon buildup inside the engine, the shuddering can become even more severe. Therefore, it is essential to use high-quality gasoline.
I've seen quite a few cases of BMWs shaking when accelerating by pressing the gas pedal. The most common issue is with the ignition system. If the spark plugs are worn out or the ignition coils are burnt out, a cylinder may misfire, causing the entire car to shudder during acceleration. A dirty throttle body can also cause problems - excessive carbon buildup blocking the intake will make the engine struggle to breathe smoothly when the ECU can't compensate. Clogged fuel injectors spraying unevenly will make the engine run rough. Worn or cracked engine mounts will make the whole powertrain vibrate like a foot massager. Driveshaft imbalance or worn CV joints become particularly noticeable during acceleration, especially around 40 mph or 80 mph speed ranges. A clogged fuel filter causing inadequate fuel supply will make acceleration feel weak, while improper wheel balancing makes the car wobble. I recommend checking the trouble codes first, with special attention to spark plugs and ignition coils as these are the most frequent culprits.
