Why does the Regal's idle speed fluctuate up and down?
2 Answers
The fluctuating idle speed of the car indicates that there is an air leak in the intake manifold of the car, or that the throttle body has excessive carbon deposits, causing the cross-sectional area of the air passage to change. This prevents the car's control unit from functioning properly, requiring timely repairs. Relevant information about idle speed is as follows: Introduction: Idle speed is an operating condition of a car, referring to the engine running in neutral gear. The engine speed during idle is called the idle speed. The idle speed can be adjusted by changing the size of the throttle, among other methods. Idle means the engine is producing power without doing work: Driving idle refers to the state when the car is in gear, the accelerator pedal is not pressed or is released during driving, maintaining the minimum opening of the throttle. At this time, the engine speed is the same as the parking idle speed, which is called driving idle.
After driving for so many years, I've found that the issue of unstable idling in the Buick Regal is quite common. The most frequent cause is a stuck idle control valve, which regulates the engine's air intake. When carbon buildup is excessive, it can easily clog, causing the RPM to fluctuate erratically. Another possible reason is a leak in the vacuum tube or intake manifold, leading to uneven air distribution. Other causes include a faulty throttle position sensor, which tells the ECU how to adjust the air intake; if the signal is unstable, the idle will be out of control. Fuel system problems, such as dirty or clogged fuel injectors, can also cause uneven fuel supply. Aging spark plugs in the ignition system can also affect idling. Don't underestimate this issue—unstable idling can increase fuel consumption and even lead to more significant failures. It's advisable to first check simple items yourself, like cleaning the idle control valve. If that doesn't work, take it to a professional repair shop for diagnosis immediately—don't compromise driving safety.
