Why Does an Automatic Transmission Car Shudder When Starting?
3 Answers
Automatic transmission car shudders when starting due to the following reasons: 1. The throttle is too dirty, causing uneven air intake and operation; 2. Fuel line blockage, leading to insufficient fuel supply at low throttle and uneven operation of engine cylinders; 3. Abnormal operation of the transmission; 4. Broken or burned high-voltage wires or spark plug failure, causing some cylinders to misfire and resulting in unstable engine operation; 5. Battery voltage is outside the specified range. An automatic transmission does not require the driver to manually shift gears; the vehicle automatically selects the appropriate gear based on driving speed and traffic conditions. There are six gear positions, from top to bottom: P, R, N, D, S, L.
I've encountered this situation a few times as well. Automatic transmission cars shaking during startup could be due to issues with the engine or transmission system. The most common causes are aging spark plugs or ignition coil problems, leading to unstable ignition which becomes more noticeable when the load increases during startup. Alternatively, dirty or insufficient transmission fluid can affect smooth power delivery. In some automatic transmission designs, worn clutch plates can also cause this. I recommend first checking the condition of the spark plugs and ignition system. If those are fine, then check whether the transmission fluid needs changing. Don't skimp on regular maintenance - periodic replacement of these components can prevent issues. Don't dismiss this as a minor problem; delaying repairs might lead to more serious damage. Unstable startup also affects driving safety, so it's best to have a professional shop conduct a thorough inspection.
Last time when I started my automatic transmission car, it shook violently, which was really annoying. I even thought the car was broken. Later, I took it to the repair shop, and the mechanic diagnosed it as a problem with the suspension system, such as aging shock absorbers or unbalanced tires, which worsened the shaking during startup due to dynamic balance issues. He also checked the engine mounts and said wear and tear could also cause vibrations. Now, every time I start the car, I pay attention to the sounds and get it serviced immediately if I notice any issues. During maintenance, don’t forget to check these components, such as inspecting tire wear and suspension condition every six months. Automatic transmission cars are quite sensitive to these issues, so don’t ignore any shaking—address it early to save trouble later.
