I bought a 2011 F150 platinum last Friday and it has 85k miles on it.. love the truck so far but I hear this scraping/grinding noise at acceleration. It starts when I put it in drive and first hit the gas, last for maybe a second or 2. Then If I’m driving maybe 30mph I’ll hit the gas a little to accelerate more and it does it again. I doubt it’s the tranny because it shifts very smooth and fast, could it be an issue with the exhaust? Or am I way off here?

i live in Minnesota and it is a little rusty underneath. Has the 5.0 also