What are the symptoms of a faulty throttle body?
3 Answers
The symptoms of a faulty throttle body are: 1. Unstable engine idle speed, with high idle speed persisting without dropping; 2. Difficulty in starting the engine; 3. Insufficient engine power, poor acceleration performance, and unstable operation; 4. Black smoke coming from the car's exhaust pipe; 5. The engine fault light is on. The car throttle body is a controllable valve that regulates the air entering the engine. After the air enters the intake pipe, it mixes with gasoline to form a combustible mixture, which then burns to generate power. The method to clean the throttle body is: 1. Turn off the ignition switch and disconnect the negative terminal of the battery; 2. Remove the throttle cable, intake hose, and the screws fixing the throttle body in sequence; 3. Use a cleaning agent to clean the throttle body, and use a cotton thread to wipe areas that are hard to reach.
Last time my friend's Lavida had sluggish acceleration when stepping on the gas, and the idle was shaking violently with the tachometer needle dancing wildly. At the repair shop, they plugged in the diagnostic computer which showed a fault code for abnormal throttle position sensor. The mechanic said when this component gets dirty or fails, it affects air flow calculation, causing the engine control unit to send incorrect commands. The most obvious symptoms are cold start difficulties, with idle speed either frighteningly high or stalling directly. Fuel consumption jumped by 30%, and black smoke came from the exhaust pipe. They sprayed carburetor cleaner on the throttle plate, but that was only a temporary fix. Eventually, replacing the entire throttle body assembly solved the problem. My advice: if you notice similar symptoms, don't push your luck - electronic throttle systems are much more troublesome to repair than cable-operated ones.
A faulty throttle body can cause more than just sluggish acceleration. Once when I was driving an old Passat on the highway, the car would jerk forward when I pressed the gas, as if someone was pulling it from behind. After stopping, I opened the engine compartment and touched the intake pipe, only to find the throttle body was alarmingly hot. The mechanic said a stuck throttle motor would make the throttle plate open and close erratically. The most dangerous scenario is when the idle speed suddenly surges to 3000 RPM, making it hard to stop even with the brakes on. It also tends to trigger the check engine light, and the emissions will definitely fail the annual inspection. They had to use specialized equipment to reset the throttle opening data to fix it. In modern cars, an inaccurate throttle position can also affect the transmission shift logic, making the problem increasingly complex.