Some 2020-2023 Escape and 2021-2023 Bronco Sport vehicles equipped with the 1.5L engine may exhibit a lugging vibration and/or boom noise while driving in gears 5-8 at approximately 1500 engine revolutions per minute (RPM). This may be felt more when the engine is under a light to moderate load. A vibration and/or boom noise could be generated from the firing frequency of the 3 cylinders or when cylinder deactivation occurs and the engine is running on 2 cylinders. This condition is more noticeable when the vehicle is driven in ECO mode. This mode was designed to deliver maximum fuel efficiency and increase the driving range.
