What Causes the Abnormal Noise When Starting an Automatic Transmission Car with Throttle?
3 Answers
Here are the specific reasons for abnormal noise when starting an automatic transmission car: 1. Poor fuel flow: Insufficient fuel supply at low throttle causes uneven operation of engine cylinders, leading to shaking. 2. Dirty throttle body: Uneven intake causes uneven operation and shaking. When there is excessive carbon buildup inside the engine, the gasoline sprayed by the cold start injector is largely absorbed by the carbon deposits, resulting in a lean mixture during cold starts and making it difficult to start. 3. Broken or burned high-voltage wires or spark plug failure in one cylinder, causing the engine to operate unevenly and shake. 4. Check whether the battery voltage is within the specified range. 5. Abnormal operation of the transmission.
Recently, when I start my automatic car and step on the gas, it makes a buzzing noise, which is quite annoying. Possible causes include insufficient or old transmission fluid, as low fluid levels can cause internal parts to grind against each other; or a worn-out CV axle, which connects to the wheels and can produce clicking noises when turning or accelerating. I also noticed that loose suspension components, like control arms or links, can cause strange noises, especially on bumpy roads. The buzzing noise when accelerating from a stop isn't just annoying—it could also hide safety risks, like making the problem worse if ignored. So, I quickly took my car to the shop, and after changing the transmission fluid and tightening some bolts, the issue was fixed. I recommend regular maintenance, checking fluids and the chassis to prevent small issues from becoming big ones. Remember, don’t push through problems—getting them fixed by a professional is safer and more reliable.
I've been driving for many years, and abnormal noises during automatic transmission startup are commonly found in a few areas. One is issues with the drivetrain, such as worn differential gears, which can cause squeaking when the power transmission is unstable during acceleration; another is loose or cracked engine belts, leading to a rustling sound during startup and acceleration. There are also cases where bearings are damaged, especially the front wheel bearings, making more noise during turns and acceleration. I once encountered a similar issue and delayed repairs until the noise worsened, costing me a lot. So, I recommend first identifying the source of the noise—whether it's from the chassis or the engine compartment—then checking the oil level and belts. Don't try to save time by fixing it yourself; head to a reliable repair shop promptly. Regularly maintaining fresh transmission fluid and changing it every two years can help prevent such issues.
