The sales representative said he had the truck inside for one night, and it was not any oil on the floor. The mechanic who looked over it said its oil coming from somewhere at the upper part, but was not able to locate it. Mhm.. They use a lot of salt on our winteroads, so we need to steam the cars pretty often . I think the chevy's, we got some tahoe and suburbans around here, rust much more.
I will give you the best advice you will ever get.
Before you leave your home search the internet at whitepages.com to locate a diesel mechanic in the same area were the truck is.
Call that diesel mechanic and ask him to go and complete a full inspection, full system test and test drive truck.
It will cost you any were from 100-300 bucks but it will save you a lot of money if the truck is junk.
Explain to him that you want to make sure this truck is good prior to purchase.
You should contact the dealership and advise them you will buy the truck providing that it passes the inspection from the mechanic.
Make sure you have it in writing that the dealership is not to sell the truck to anyone unless you advise them that you will not purchase it.
Have a clause in the agreement that should the dealership sell the vehicle after it has been inspected that they are to repay you the costs of the inspection.
You should plan on purchasing the vehicle immedatly should the truck passes the inspection. Because by law you would have a duty to complete the sale within a reasonable time. Not several days to weeks later.
DO NOT TRUST A DEALERSHIP MECHANIC WERE YOU ARE TRYING TO BUY A VEHICLE