Although this is not about a ranger, I'd like to share this little story with you all anyways.
So yesterday evening around 5:30, my sister was on her way out to head back to school for the week. (she drives my Cherokee)
She starts it up, puts it in reverse to go ahead and back out of the driveway and I hear some of the worst noises going on underneath the hood.
I stop her, tell her to pop the hood and what do ya know, she's 2 quarts low on oil. Luckily I planned on an oil change anyways soon, so I had everything sitting in the driveway. Put in fresh oil and a filter and away she went about 30 minutes later without any problems.
Sometimes I think the engine could be on fire and she wouldn't even notice it.
Moral of the story. CHECK YOUR DAMN OIL.