What is the reason for the Volkswagen Bora idling at 1200 rpm?
2 Answers
Idling at 1200 rpm is designed as a cold fast idle to quickly raise the engine temperature to normal operating levels when the car is cold. Once the temperature reaches normal levels, it automatically returns to normal idle speed. Therefore, this occurs every time the car is cold started, which is a normal phenomenon. Idling: It is an operating condition of a car, referring to the engine running in neutral gear. The engine speed during idling is called the idle speed. Cold fast idle: When the car is cold started, the vehicle's computer allows the engine to have a high idle speed for several seconds to about a minute. Once the coolant temperature rises to the set temperature, the idle speed returns to normal.
I have over a decade of car repair experience. The high idle speed of the Bora at 1200 RPM is usually caused by excessive carbon buildup in the throttle body. Dust and oil residue narrow the air passage, making the engine computer think it needs more power, thus automatically increasing the RPM. This could also be due to the idle control valve sticking in the closed position or a vacuum hose leak, especially in older cars where plastic hoses are prone to aging and cracking. If the temperature sensor malfunctions, the car may misjudge the weather as cold, leading to a slightly higher idle speed. I recommend first trying to clean the throttle body yourself using a cleaning spray to remove stubborn carbon deposits, or checking the vacuum hoses for any hissing sounds indicating leaks. A consistently high idle speed not only wastes fuel but also increases engine vibration, damaging the piston rings. If the RPM remains high after cleaning, it's best to use a diagnostic tool to read the fault codes and ensure there are no hidden ECU setting issues. Addressing the problem early can save both hassle and money.
