Can my ex put a lien on my vehicle?

I've been divorced for a while now and my vehicle is complete in my name. The title, the insurance, everything!!! My x just came out of the wood work claiming I owe him money (which I haven't heard anything about until now) and he said he will put a lien on my vehicle if I do not pay him? (He is a coal miner making ohhh 28 dollars an hour and I struggle at my part time minimum wage job).... which btw, I also did not seek any spousal support from him and signed all my rights away for his retirement. I didn't earn any of that money so I didn't deserve it. I thought I would be a decent women and not make him pay for support and now he turns around and claims I owe him? I thought I did him a favor... can he legally lien my vehicle?