What would you do?

[Raptor]

I am pretty sure that legally he is under no obligation to help. That does not however mean that he can't be taken to small claims court where verbal comments could be taken into consideration as far as what John told him when he sold it etc. So it is possible that some civil action could be a problem but most people will not go through the hassle etc of filing a claim and the time frame involved.

Besides all the legal issue of liability and otherwise, if the car was truely sold without the thought of screwing the buyer, I do think it would at least be fair to help him troubleshoot the problem. Who did the work on the car? The timing belt, head gasket etc?