2016 CX-5 Grand Touring 153k mi
My rpm normally sits around 500 when I am either idle, at a stop light, or in park. As of recently, it has begin to drop below the 500 then essentially knock or thump and then raise up to 1500 or so for a second or more then settle back down to repeat the process. The issue does not happen when I am in motion driving. When I put it in reverse and idle backwards (without pressing gas pedal) it will jerk, jerk, jerk while rolling backwards. The issue seems to diminish greatly (although not entirely (rpm jumping around is less intense than the <500->1500) when the AC unit is turned off. When the ac is turned off I start to smell a musty wet and somewhat warm air.
When I drive for a long period (day or more) without the ac on, the knocking is less and the check engine light goes off. When I turn on ac for extended period, the engine will again knock and the check engine light comes on. Does anyone have any idea what is going on?
My rpm normally sits around 500 when I am either idle, at a stop light, or in park. As of recently, it has begin to drop below the 500 then essentially knock or thump and then raise up to 1500 or so for a second or more then settle back down to repeat the process. The issue does not happen when I am in motion driving. When I put it in reverse and idle backwards (without pressing gas pedal) it will jerk, jerk, jerk while rolling backwards. The issue seems to diminish greatly (although not entirely (rpm jumping around is less intense than the <500->1500) when the AC unit is turned off. When the ac is turned off I start to smell a musty wet and somewhat warm air.
When I drive for a long period (day or more) without the ac on, the knocking is less and the check engine light goes off. When I turn on ac for extended period, the engine will again knock and the check engine light comes on. Does anyone have any idea what is going on?
