Loud roar while accelerating and overheating?

The SUV listed above has run extremely well until recently (only non-routine maintenance has been all 8 spark plugs were replaced recently). There is a loud roar while accelerating that only subsides shortly after each upshift. While maintaining speed the engine sounds fine. Just recently the engine temperature spiked up while on city roads and I pulled over and waited for it to cool. After, I drove about 30 minutes home with no temperature issues, just noise. I was wondering if these issues were related at all, maybe something with the exhaust.