What Causes Unstable Idling in a New Car?

[DePeter]

New car unstable idling reasons are as follows: Air filter: If the air filter is not replaced in time, it will cause insufficient air intake and reduce engine idle speed. Abnormal water temperature: High engine water temperature will cause early ignition timing, change the air-fuel mixture ratio, and thin the engine oil viscosity (poor lubrication). Causes of abnormal water temperature include: insufficient coolant, thermostat not opening, fan failure, and inaccurate temperature control switch. Excessive carbon buildup in throttle body and air flow meter: The throttle body and air flow meter are prone to dirt. Most modern cars use electronic throttle bodies, and even slight carbon buildup can affect them. Excessive carbon buildup in the throttle body can cause throttle sticking, severe power loss, and unstable idling. Clogged fuel injectors: Clogged fuel injectors will result in inconsistent fuel injection amounts, causing uneven cylinder operation and leading to unstable ignition and idling.