Why Does a New Car Shake at Idle?
3 Answers
Reasons for a new car shaking at idle: 1. Severe carbon buildup; 2. Ignition system failure: If the car's ignition system malfunctions or the spark plugs are damaged, fuel cannot be effectively burned in the cylinders; 3. Fuel injector failure: Uneven fuel injection among the engine cylinders due to faulty injectors can also cause idle shaking. It is normal for a new car to shake at idle. Generally, when a car starts cold, the RPM may shake between 900 to 1,100 per minute. After warming up, the RPM will stabilize around 800 per minute, reaching normal levels. When the engine is running and the accelerator pedal is completely released, the engine is in an idle state.
New car idle shaking is quite common, and I also encountered this issue with the car I bought recently. At first, I thought it was normal, but later the shaking became more noticeable. After consulting, I learned that this might be a minor issue specific to the break-in period of a new car, such as uneven ignition from the engine spark plugs, leading to unstable combustion and affecting idle stability. Additionally, if the fuel injectors are clogged, causing an imbalance in the air-fuel mixture, or if the air flow sensor readings are inaccurate, the engine can also shake. Carbon deposits are rare in low-mileage new cars but can accumulate too quickly if the car is not used properly. Sometimes, if the ECU control software isn't set up correctly or the idle parameters aren't optimized, it can easily trigger this problem. It's advisable not to ignore it; new cars usually come with a warranty. Taking it back to the 4S dealership for a simple scan and cleaning can often resolve the issue. Addressing it early can prevent more serious problems later on.
Idle shaking often occurs in vehicles, even new ones. Possible causes include ignition system issues, such as faulty spark plugs or ignition coils affecting the firing sequence; fuel system problems like carbon-clogged injectors disrupting fuel supply; and intake system leaks allowing unfiltered air to mix in, disturbing the air flow sensor readings and causing unstable engine operation. Even new cars can experience loose or vibrating engine mounts if improperly installed. For troubleshooting, start with simple steps like cleaning the throttle body or replacing spark plugs; if the issue persists, check wiring or ECU software settings. For new vehicles, it's best to return them to the manufacturer for professional diagnosis and resolution by their expert team to prevent potential hazards. Regular maintenance can also reduce the likelihood of such issues.
