Why does my 2005 bmw 325i series have a burn smell coming thru the a/c vents. on 2005 BMW 325i

why is this smell of burning rubber coming thru my a/c vents. Could it be the valve cover gasket leaking?

Asked by for the 2005 BMW 325i
i doubt it. if it is when the ac is on, there may be something inside the vent system. something may have dropped in there or the blower motor itself may be failing.

I just had an oil change and fuel pump replaced and after that is when I began noticing the smell of burnt oil/rubber. The smell is faint, but when I am at a drive thru with the window down it is really strong. I was told the A/C Compressor could be going out or the Valve Cover Gasket needed some work??