Connecting Rod Bearing Noise
WARNING: This page is about a different car, the 2011 RAM Pickup and 2011 RAM Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
Connecting rods with excessive clearance knock at all engine speeds, and under both idle and load conditions. The knock is usually rhythmic and the speed and volume will increase and decrease relative to engine speed. When the bearings begin to become loose, the noise can sometimes be confused with piston slap or loose piston pins. Low oil pressure can also accompany this condition. Look for an oil light on instrument cluster.