If its loud, then there might be a ball-bearing in the fan that is messed up. If its possible to contact Dell support and order a new fan and it looks easy to replace that might be an option.

Another option would be to do as the post does with undervolting: (original post in SF by SlasherIT)

Guide to Cooling Down Your Notebook Computer

(Be Careful with this though and backup your data and go slow if you do undervolting.)