All the above post offer solid suggestions.
If it was mine and it was not a belt or belt driven component generating the sound my next move would be to inspect the oil for metal shavings. Grab a glossy black oil or antifreeze jug and with the engine running pull the dipstick then deposit some...
A unused with tags Watershed Weapons Bag in their most popular size.
If you do not want your rifle to get wet when you swim across the Mississippi River this is the bag your need.
If you are not familiar with Watershed products here the link to this product...
I have shot skeet from the upper deck.
Think of a cruise ship as a huge suv on wheels. It's very comfortable to travel on. To me the positives outweigh the negatives.