Car Sale issue..

I bought a car 4 months ago, private sell. Didn’t drive it much. I decided to sell it to a used car lot. I told the person everything I knew about the car. Needed a power steering unit and the back brakes. The guy drove it around the block and looked it over. He offered me money and I sold it to him. There was no contract or anything. He called me a few hours later after his mechanic put it on a lift (which I had never had done and I told him that) stating the frame was bad and that he wanted the money back. He keeps saying I told him and his mechanic that the frame was good and every time I correct him and tell him that I did not say that and I only repeated to him what I was told making it clear that I did not know for sure. Now he is threatening me with legal action and intimidation, “Your going to have a world of hurt headed your way.” He also made it known he went to the bank and got a copy of my license and the check he wrote me from when I cashed it. I explained multiple times that I was told the frame was fine but made no guarantees of anything. I told him what I knew about it and what I was told. I said “As far as I know” making no claims that I was absolutely certain of. He looked it over and drove it around the block. He then offered the money. I agreed on the amount and he wrote a check and I left. No contract. Nothing. That was it.

He keeps calling and texting me and saying he either wants me to buy the car back from him or give him the car and pay the “difference” of what he lost out. And that I better come up with a solution for have consequences.

Am I legally obligated to return the money? What should I do?

Location: Ohio