What Causes an Automatic Transmission Car to Stall at Idle?
1 Answers
Automatic transmission cars may experience shaking, vibration, or stalling at idle due to several reasons, including severe engine carbon buildup, ignition system issues, unstable oil pressure, and aging engine components. The specific causes are as follows: Severe Engine Carbon Buildup: A common cause of car shaking is a dirty throttle body or excessive carbon deposits in the fuel injectors. Solution: Clean the fuel system and check whether the idle control valve has carbon buildup—clean if necessary. Ignition System Issues: Inspect the condition of the spark plugs, high-voltage wires, and ignition coils. Poor ignition system performance or weak spark plug firing can also lead to such issues. Solution: Check if the spark plugs have excessive carbon buildup and replace them if needed. Unstable Oil Pressure: If you have already cleaned the engine carbon buildup, throttle body, replaced gaskets, and spark plugs but still notice shaking at idle, it is recommended to visit a 4S shop to check the fuel supply pressure and the intake pressure sensor. Abnormal fuel pump pressure or faulty intake pressure sensor readings can cause body shaking. Solution: Check the oil pressure and replace components if necessary. Aging Engine Components: Car shaking can also be related to the aging of engine mounts (also known as engine mounts or cushions). Engine mounts absorb minor vibrations during engine operation. If the mounts are faulty, these vibrations can transfer to the steering wheel and the cabin, causing shaking at idle. Solution: Replace the components.
