What are the causes of idle shaking in a new car?
2 Answers
New car idle shaking may be caused by the following reasons: 1. Engine carbon deposits: Excessive carbon deposits inside the engine can cause idle shaking after a cold start. Due to excessive carbon deposits, a large amount of gas sprayed by the engine will be absorbed by the carbon deposits, resulting in an overly lean air-fuel mixture, which makes starting difficult and causes shaking. 2. Ignition system issues: Poor performance of the ignition system or suboptimal spark plug firing can lead to idle shaking in a new car. 3. Unstable fuel pressure: Abnormal fuel pump supply pressure or incorrect readings and poor performance of the intake pressure sensor can cause body shaking. It is recommended to check the fuel supply pressure and intake pressure sensor at a 4S shop to ensure they are functioning properly.
My newly bought car shakes badly when stopping at a red light, and the inspection found that it might be due to improperly installed or dirty spark plugs. A new car should run smoothly, but slight shaking during the break-in period is normal; however, if it's severe, it could indicate a clogged fuel system or carbon buildup in the throttle. I also suspect loose engine mounts—if they weren't properly secured during factory assembly, this could happen. Idle shaking makes the ride uncomfortable and raises concerns about engine longevity. It's recommended to return to the 4S shop for diagnostics as soon as possible—don't delay. They can use diagnostic tools to check if it's an ECU calibration issue. New cars come with a warranty, so repairs are usually free. Additionally, driving habits like sudden stops and starts can worsen the shaking, so smooth driving is crucial.
