Burnt oil smell

I noticed yesterday a burnt oil smell coming from my 2000 Mirage. I can see smoke coming from the hood if I'm at a stop light. What could it be? And will it cost a lot to fix?

check the valve cover seal. it may be time to change it. and may be leekin onto the block or exhaust manifold, before mine was changed it was leekin and dryrotted from the heat.