I deliver for Doordash in my 2012 Mazda3i Touring 4dr sedan with 165k miles and the Skyactiv 2.0L engine gets an odd, maybe oily smell in the the AC after I push it hard. The smell does not occur under normal driving. Only when I push it hard when pulling out on the highway or accelerating onto the interstate. It has also started burning half a quart of oil between changes. No codes, no check engine light.

I've had the radiator replaced 3 years ago from an unfortunate encounter with a ditch and the power steering repaired in the past year. Brakes are fine all around as are the tires.

What could be causing this smell?

Thanks in advance Scotty and Crew!