Burning smell from under the hood

Hello
 
I have a 2005 Mercedes C320 with only lil over 13k on the speedometer.  I can smell something burning  from inside the hood of the my car.  I have taken it to the dealership and they told me they can not find anything wrong.  I was hoping maybe some of the forum menbers have encountered this problem before?  My warranty is about to run out on my car.  I want to fix this problem before it does!  Any help is greatly appreciated.
 
Thanks again
 
Nancy

I don't have a benz but would check to see if any wires are touching the exhaust manifold or if you have a rocker cover gasket leaking
did you get this smell after you had an oil change? if so maybe its oil burning on the exhaust manifold?
sorry can't be much more help
bill