I own a 2009 Santa Fe. On Dec. 19, I started my car to head to the airport and it did not want to start. It was a scarey few minutes because I was to catch a flight in one hour. Eventually the car started but from that time on, every time I start my car for the first few miles, it sounds like a diesel engine. It not only idles loudly but when I accelerate the engine is very loud. Eventually it stops making the noise and doesn't seem to affect the performance of the car. Has anyone ever heard of this problem?

 

Is it a loud roar/whirring sound (fan clutch could be stuck), or is it a clattering sound (pinging/detonation due to bad timing, or lack of lubrication to valvetrain)?