I am a retired Master Auto tech with 30 years in the trade. This noise is not normal despite what the dealer says. The noise lasts for seconds but is consistent with a oil pump that loses its prime after sitting for a while. It could also be a timing chain tension. It has a Nissan filter and Valvoline oil in it to specs so don't let them tell you to try that first. The point is every time the engine starts something is not getting lubricated. This will ultimately lead to a premature engine repair. Mine is still under the 60000 mile warranty and I am going to pursue it with Nissan.