Ok, on the TIP right side is what they call Final Drive, the axle seal is known to develop a leak and what happens, the fluid from the final drive is thrown outward and will drip down on the exhaust and the engine under cover pan. If you over fill the TIP you could have TIP fluid mixing in the Final Drive gear lube. Mine is leaking because the seal is going bad and will be fixed in the next several weeks by an Indy for about $300. Now, burning oil and hypo oil have a completely different smell when they burn, also the smell from the right side air intake is very strong. As far as I know, if you have an oil smell check your cam covers and the cam access plugs.
