Check out this video for what to check if your heat or ac fans are making rattling, clunking or vibrating noises while they're on. It may be an easy fix!
How to repair, install, fix, change or replace a broken radiator A/C Condenser cooling fan. If your car overheats or runs hot and the cooling fan will not turn on then this may be your solution. This video shows the process for 2001, 2002, 2003, 2004, 2005, 2006 Hyundai Elantra 2.0L.