Welcome from TN, sorry to hear this, I have no solid answers. Did the seller indicate issues or mileage? Hope it is not time for a new motor but who knows, someone with more knowledge will hope on the post and help out.
About 12,000 miles, the only issue before buying was rust build up in tank, fuel lines, and injectors. All of that has been replaced thoughWelcome from TN, sorry to hear this, I have no solid answers. Did the seller indicate issues or mileage? Hope it is not time for a new motor but who knows, someone with more knowledge will hope on the post and help out.