I have a 2007 Murano with the VQ35DE V6. The vehicle has 105K on it and lately I have been noticing a very brief engine knock on startup. Cold starts are OK, it's when the engine has been warm that I experience the knock. The knock does not occur on every warm start.The knock is random and lasts less than a second, yet it is noticeable. The low oil pressure light flickers on-off-on-off during this occurrence. I use Nissan OEM oil filters.