Started having noises from the engine. Had it looked at and couldn't find the issue. About 2 months later replaced the idler pulley after seeing it was failing. Thinking that was the problem couldn't help but notice engine still having a knocking noise. After it got warmer out the noise repeated only to spot that Harmonic Balancer shaking and wobbling to the engine knocking. Thus destroying my new idler pulley.

Note: that if Harmonic Balancer Pulley fails will cause major engine damage or complete failure.