My 1999 Dodge Durango was great at 5000 miles also. AT 40000 miles it gave the first indication of no oil pressure. As soon as I stopped the pressure came back. To the shop, replace sending unit. That lasted just long enough for the extended warranty to expire, then the problem occurred again. Second sending unit, good for a few thousand miles, then no pressure again. Another sending unit and assurances from one dealership that I did not have a problem. They had it hooked to their machine when the gauge went to zero and it still had pressure. However, they weren't sure what was wrong. At 105,000 miles I had the dubious honor of paying 5,000 dollars for a new engine. I bought this from a Dodge Dealer. Fortunately I got 3 year, 36,000 mile warranty on the new engine. Just under one year and around 14,000 miles later, it is presently in the shop because the oil pressure dropped to zero. First thing the dealer said was sending unit. My wife told him to tell that tale to others as we had heard it before.
If I ever win a lottery, I will spend whatever to get a chopper to drop this thing through the roof of the nearest Dodge Service Center. I am still upset that the government spent my tax dollars to bail Chrysler Motors out way back when. We would all be better off it they had just gone bust. Wouldn't be quite so bad if they would just admit they have a problem.
I have 178,000 on my 1998, 318 engine with 4-wheel drive. Runs great, changed oil and filter every 3000 miles. That's right, it's not new and you have to replace parts every once in a while, recently ball joints and a used starter. Spark plugs at 100,000 and again at 170,000. Drives great, wish I could get a new one just like it.