2008 BMW e90 328i burning smell

[traverscott74]

I would appreciate ANY help because really, I am at my wit’s end now. I have a second hand BMW e90 328i 2008 model I bought from a family friend. It’s been used for 3 years now and I noticed that 3 minutes right after I turn the engine on and drive the car away, I smell a somewhat burning oil from the air vents – I can’t figure out if it’s the oil or transmission fluid. But there was not even a single mark of fluid on the engine area. But there was, however, a small drop of fluid on the ground where the car’s been parked for certain days.
Searched all over the internet but I am still confused to what the problem might be. What do you say?