Can i be sued for a vehicle i sold a few months after the sale

I sold a vehicle a few months ago. I replaced the spark plugs and coil on plugs and stated i gave the vehicle a tune up. I offerd the buyer to take the car to a mechanic; this was declined. I have screen shota of proof ahe declined and I offered this. Anyways, after 2 montha of owning the vehicle,, i receive a threatening measage on facebook claiming the vehicle had over heated and blew the engine. The claim is i added a stop leak formula to the radiator and that what blew the engine. I did not add the stop leak to the engine. There's also claims that I had never put in New plugs or coil on plugs supposedly by a mechanic. I did replace them but i don't have receipts. There's also a claim that i purposely sold the car in that condition in hopes to blow up and kill them. And yes i have screen shots of her saying this. My question is, can i be held liable for this as i never offered a warranty? She claims I messaged her saying if theres a problem for her to message me. I don't think I di