Please excuse my newbieness, but how would i test the oil pressure or what is the gauge called i need? (oil pressure gauge?lol) These guys have been trying to pin point it for the last couple days, but can't get the noise to last more than a couple minutes if at all. They are tending toward a chain issue but don't understand why it only makes any noise except during idle. The recommendation was to just drive it until it makes noise more consistently to be able to figure it out. I asked about the oil pressure theory and they seemed skeptical and said there would be an oil light, whether that's true or not. Id like to check it myself though. Please let me know how i do that. Also, if the the chain ends up flying off and I need a new engine, is there any difference between a 4.0 in a 2wd ranger and a 4wd one? I've found a few engines with 35k for 700 bucks not too far out of 03 rangers.