What causes severe car shaking and lack of acceleration power?
3 Answers
Severe car shaking and lack of acceleration power are primarily caused by excessive carbon buildup in the throttle body, which obstructs proper air intake. Here's some information about the throttle body's functions: Function: Its main purpose is to detect whether the engine is in idle condition or under load, and whether it's in acceleration or deceleration mode. Location: The throttle position sensor, also known as the throttle opening sensor or throttle switch, is a device used to monitor the engine's operating state. It essentially consists of a variable resistor and several switches, installed on the throttle body. Operation method: The resistor's rotating shaft is connected to the throttle. It has two contact points: a full-open contact and an idle contact. When the throttle is in the idle position, the idle contact closes, sending an idle condition signal to the computer. When the throttle is in other positions, the idle contact opens, outputting voltage signals corresponding to different throttle angles. The computer then identifies the engine's load based on the signal voltage value, and determines whether the engine is accelerating or decelerating based on the rate of voltage change over a certain period.
I've been repairing cars for over 20 years, and when a car shakes and lacks power, it's usually due to problems in three areas. The most common issue is the ignition system failing—ignition coils cracking, spark plugs wearing out, or spark plug wires fraying. Gasoline is injected but can't ignite, and the engine definitely struggles to breathe. Then there's the fuel delivery system getting clogged—fuel pump screens blocked like honeycombs or fuel injectors caked with carbon deposits, preventing fuel from reaching properly. Finally, pay attention to the intake system, like air intake leaks or throttle bodies gummed up with sludge, messing up the air-fuel ratio and making the engine sputter. The most deceptive issue is worn-out engine mounts, shaking so much you'd think the engine is about to fall out, and wasting a lot of effort for nothing.
Last week, I had this awful experience while driving my kid to school—stepping on the gas pedal all the way, yet the car just crawled forward sluggishly, and the steering wheel shook like a phone vibrating. The scariest part was when the engine suddenly cut out during an overtake, making the car jerk as if it had been shot. After towing it to the repair shop, they found all four spark plugs were completely worn out, and one ignition coil had a crack. The mechanic said the spark plugs hadn’t been replaced in six years, with the electrodes burned down to barely half their original length. A reminder to everyone: if your steering wheel starts vibrating or overtaking becomes a struggle, don’t push your luck—you might end up stranded one day. I was lucky this time; if the ignition module had completely failed, a sudden stall on the highway could’ve been extremely dangerous.
