What Causes Intermittent Idle Vibration in the LaCrosse?
1 Answers
Intermittent idle vibration in the LaCrosse may be caused by engine misfiring or insufficient battery voltage. Engine misfiring causing vehicle vibration: Misfiring refers to a condition where one or more cylinders in a four- or six-cylinder engine are not functioning or functioning poorly. This leads to unstable power output from the engine, resulting in vehicle vibration. The simplest diagnostic method for engine misfiring is the "cylinder cut-off test." Idle vibration caused by insufficient battery voltage: Turning on the headlights increases electrical load, and holding the window switch after the glass reaches the top causes the window motor to stall, rapidly multiplying the current. Both situations can lead to a drop in the vehicle's overall voltage. In response, the generator's voltage regulator increases the excitation current to raise the voltage. The increased excitation current raises the generator's operational resistance, which in turn lowers the engine speed, causing fluctuations.