What problems can a faulty throttle body cause in a car?
3 Answers
A faulty throttle body can cause the following problems in a car: unstable engine idle speed, persistently high idle speed, difficulty in engine starting, unstable engine idle speed, and no idle speed. The throttle body is a controllable valve that regulates the air entering the engine. After the air enters the intake manifold, it mixes with gasoline to form a combustible mixture, which burns to produce power. It is connected to the air filter at the top and the engine block at the bottom, and is referred to as the throat of the car engine. There are two types of throttle bodies: the traditional cable-operated type and the electronic throttle body. In traditional engines, the throttle body operates through a cable or linkage, with one end connected to the accelerator pedal and the other to the throttle linkage plate. The electronic throttle body primarily uses a throttle position sensor to control the throttle opening angle based on the engine's required power, thereby regulating the amount of air intake.
Last time my friend's car had a throttle body failure, it was quite troublesome. The most obvious symptom was the tachometer needle jumping erratically at idle, with the car body shaking like a phone on vibrate mode. Accelerating required extra effort on the gas pedal, feeling like someone was holding the car back. Cold starts needed keeping the throttle pressed to fire up, and fuel consumption suddenly increased by 20-30%. Even more annoying was the constant engine warning light and the transmission acting up during gear shifts. These issues ultimately stem from uncontrolled air intake, confusing the ECU about proper fuel delivery. If this happens on highways, it's extremely dangerous - I'd recommend calling roadside assistance for towing to a professional repair shop immediately.
My old car had throttle body issues last year. It was particularly difficult to start in the morning, requiring multiple ignition attempts. At red lights, the shaking was so severe that the rearview mirror vibrated, and the steering wheel trembled too. On the highway, acceleration was sluggish, requiring triple the usual distance for overtaking. The engine warning light on the dashboard kept illuminating, and fuel consumption was absurdly high, burning an extra 4 liters per 100 kilometers. The mechanic later explained that the throttle plate was stuck, causing insufficient air intake and throwing the ECU programming into chaos. Such faults should never be neglected, as they can cause collateral damage to the oxygen sensor and catalytic converter, leading to even costlier repairs.
