I have the same thing going on with a vehicle I just purchased. 2004 Murano SL AWD with 30k. The dealership said the engine was perfect, but it almost sounds like a stuck lifter. The only two things I found on the internet it might be are the fuel damper, or the belt tensioner, both are named items that cause this noise. I still need to do more research. Wonderful when you have to try and pipoint an item yourself and then take it to someone "trained". Anyway Ill let you know if either of these are fixes.
The 2012 Nissan Murano has a V6 engine.
The 2013 Nissan Murano has a V6 engine.
The 2009 Nissan Murano has a V6 engine.
The 2014 Nissan Murano has a V6 engine.
The 2011 Nissan Murano has a V6 engine.
The 2003 Nissan Murano has a V6 engine.
The 2004 Nissan Murano has a V6 engine.
The 2005 Nissan Murano has a V6 engine.
The 2007 Nissan Murano has a V6 engine.
The 2006 Nissan Murano has a V6 engine.
The 2010 Nissan Murano has a V6 engine.
The 2014 Nissan Murano-Crosscabriolet has a V6 engine.