Maybe something small. My 2010 Vrs was running very rough and sourced the problem to the clutch in A/C sound dramatically changed when A/c is switched on and off.

Try this and see if Engine noise changes.

If it does clutch on A/C comprressor needs changing or worse a new A/C Comprerssor is needed

sorry posted twice 

Edited 4 August, 201510 yr by demps88