Symptoms of Idle Motor Failure?
3 Answers
Symptoms of idle motor failure are as follows: 1. The car sometimes fails to start, may stall at idle, but can sometimes start again, and runs normally after acceleration. 2. Unstable idle speed, idle shaking. 3. Engine idle speed is too high. 4. Engine idle speed is too low. The following are the causes of idle motor failure: 1. Irregular idle speed. One of the most common symptoms associated with a faulty air control valve is irregular idle speed. The idle air control valve is programmed to regulate and maintain the engine idle speed at a constant rate. If the valve malfunctions or has any issues, it may cause the idle speed to fluctuate. 2. Check engine light comes on. Another symptom of a potential issue with the idle control valve is the illumination of the check engine light. If the engine control module detects a problem with the idle air control valve circuit or signal, it will trigger the check engine light to alert the driver of the issue. 3. Engine stalls. A more severe symptom of an idle control valve problem is engine stalling. If the idle control valve fails completely, it may leave the vehicle without an air source to maintain proper idle.
After years of repairing cars, I've seen many symptoms of idle control valve issues. The most common is unstable engine idle speed, fluctuating up and down, making the car feel like a boat rocking on water. It's prone to stalling, especially noticeable after warming up and stopping at traffic lights, sometimes even making starting difficult. The car body may vibrate noticeably, with passengers feeling the whole vehicle tremble. Occasionally, the idle speed runs too high, wasting fuel in neutral. The check engine light might come on, and other symptoms like rough acceleration or abnormal exhaust emissions can occur. The main cause is usually carbon buildup inside the valve causing blockage or sticking. I recommend owners not delay—first check the air filter and throttle body, try cleaning them. In severe cases, the valve needs replacement. Small faults left unattended can increase fuel consumption and potentially harm overall engine health. Regular maintenance to keep components clean is key to preventing dirt accumulation.
As a car owner, I encountered an idle speed motor malfunction last year, which was quite annoying. The engine speed was erratic at idle, and the car would suddenly shake a few times or even stall when waiting at traffic lights. After starting, it often ran unsteadily, and the situation worsened when the air conditioning or headlights were turned on—the RPM would jump around uncontrollably. There was also noticeable shaking, and I could clearly feel the car vibrating from the driver's seat. Fuel consumption increased significantly. The mechanic diagnosed it as a faulty motor, and replacing it solved the problem. It cost over 200 yuan, but it was worth it. Safety comes first—idle speed issues are a driving hazard, so fixing them early prevents breakdowns that could disrupt traffic. Regular maintenance is key, and don't ignore minor unusual noises.
