So our Nissan Cube makes a strange sound when it starts. It sounds like a grunting/ grinding noise. (Sort of like grinding your gears when you don't clutch properly, but this is an automatic) We asked the mechanic and he looked it up and printed a page from Nissan saying that it's the computer software booting up. It sounds more transmission like than that. We asked the mechanic if we could start up another Cube of the same year to see if it make the sound. It didn't. He's looked at the sound thoroughly and can't even explain what it could be. If it's related to the fan blower being filled with dirt and leaves that's also being fixed, and the sound stops, maybe I'll have an idea of what it is/was.