So in all of these Agro-business classes you speak of, I guess they told you about libel and slander... you know, making accusations as to defame someone without having first hand knowledge as to the validity of the claim, and how you could be held responsible for any harm it may cause the other party?????
Jealousy has nothing to do with it really.... Motive doesn't matter in a libel case.
As far as the money you have already paid, I'm assuming you guys settled on a discounted(lower) price for said engine when you brought your concerns about it to the Dillards? If not, and you started paying on it without raising concerns, I'd say that you pretty much sealed your fate with this one. The way I see it without having any first hand knowledge of this transaction, just reading here, you guys verbally agreed to a price, you took delivery, and began making payments. At some point, you stopped doing so, and now we have us a horrible dispute on the interwebs.... Am I in the ballpark?