Hi 3000 hrs on a rebuild doesn't sound like a lot for a Deere motor to me everybody says they can be high hour tractors and not touched.
How hard does this tractor work and how regulars the servicing?, Im kinda wondering if the bores are glazed up and it needs a good hard days work to break the glaze. I have seen this with a few tractors before that don't run hot or just run round the yard/field and do light work. I guess it also depends how good the rebuild was too. These are just my thoughts on it but you know whats in your yard. Regards Robert