Why does my newly purchased car have idle vibration?

[Leonardo]

The reasons for idle vibration in a newly purchased car are as follows: 1. Engine mechanical failures such as improperly closing valves or uneven cylinder pressure among cylinders. 2. Dirty throttle body or damaged throttle in the air supply system. 3. Low fuel supply system pressure or significant fluctuations, severe carbon buildup in fuel injectors, etc. Generally, the more cylinders an engine has, the less noticeable the idle vibration. The inline-six engine, due to its structure, can automatically balance vibrations, making it the smoothest. On the other hand, the increasingly popular three-cylinder engines have inherently poor smoothness and require a balance mechanism to maintain normal operation.

[VonBrooklyn]

Just bought a new car and it shakes at idle, this issue is quite familiar to me. It might be due to the engine not being properly tuned, or the ignition coils or spark plugs not being tightly secured from the factory, leading to unstable ignition. Uneven fuel supply in the fuel system can also cause this, especially common in modern direct injection engines. Minor shaking during the break-in period of a new car is normal, but if it's too noticeable, you should pay attention, such as air leaks in the intake system or slight blockage of the air filter. It's recommended not to delay and drive back to the 4S store as soon as possible for a diagnostic check. They can perform free adjustments or replace faulty parts. As a car owner, I've encountered similar situations, and timely handling prevented the shaking from worsening and affecting driving smoothness.

[JasperLee]

My new car has only been driven for a few days, and I can feel a slight shaking at idle. This doesn't seem like the carbon buildup issue common in older cars. For new cars, it's mostly caused by assembly defects, such as improperly installed spark plugs or clogged fuel injectors. I've found that cleaning the throttle body or checking the intake pipe can help alleviate the problem. Once, my car was shaking badly, and it turned out to be loose engine mounts. After the 4S store tightened them, the issue was completely resolved. Don't underestimate this kind of shaking. If ignored, it could gradually damage internal engine components and increase maintenance costs. It's best to address it promptly during the new car warranty period for peace of mind.