i got a 94 sho mtx with 135k of hard miles i think and white smoke is coming out the tell pipes.i was running the codes and a cylinder test all ok but 538 some goose something out of range.anyway its about 48 the temp. and the white smoke a regalor thing for that temp.,but it ran about ten min. with the fan not hook up.....it gave out on the way home from buying it.so if is going to be bad i'll rebuild her.