Accelerating hear a flutter noise in upper engine

What is your question?

When pressing gas pedal, there is a distinct flutter noise in the upper engine. Almost like sound of a sewing machine. Then the noise stops after no acceleration. Accelerate again and the noise is back.

What makes this problem better or worse?

Cold nor hot makes a difference

How long has your 2012 Jeep Liberty had this problem?

Jist purchased vehicle 3/16/3018 noticed afterwards