So today my oil light came on, 2011 ranger with 4.0 engine. I stopped at oreillys and got a new sensor. Changed it, what a bitch, but I got it done.
Light is still on. Does this have to be acclimated to the system to work? THIA.

 

Take it back to O'Reillys and see if they can re-set the fault light.

 

No, to answer the direct question.

Why did you assume that you had a sensor problem? You could have an oil pressure problem. If oil level is correct the factory test method is to attach a mechanical oil pressure gauge and measure.

Are you sure it's the oil pressure light? Good luck.

 

So here’s the deal, I changed the sensor on oreillys recommendation. The light remained on. After taking to a former mechanic he recommended I disconnect the negative battery terminal. That did the trick. All is good. Thanks to everyone. Tim

 

Don't really know what that means, but good luck with it.

 

…but now the truck won’t start

My ‘89 B2 has a low oil level sensor. Does the OP’s truck have an oil pressure sensor and a level sensor? What sensor would he have replaced?

 

OP’s truck would have the dummy gauge at this point, so just the inline “switch”. Gauge stays at midpoint until pressure crashes.

 

The switch closes at a low oil pressure being developed. It opens when the pressure is below that set point, around 5 psi.
If you think 6 psi is good pressure, you likely will be shopping for a new engine or vehicle soonly.
Disconnecting wires on the suggestion of a bystander, more or less, is suggesting to ignore all those well-paid(were, anyway) engineers who worked to design, manufacture and sell the engine in your truck. Proceed at your own risk.
The better thing to do, if you really want to know, is to substitute a real gauge for the switch and note the oil pressure developed.
Report when done.
tom

 

It means he caused his truck's electronics to essentially reboot by unplugging it. I've done something similar on numerous devices (cell phones, computers, etc) that started acting strangely and it usually will clear it up. Not always, but it's not much work, doesn't cost anything, and is worth taking a shot.

 

40-60 psi is considered normal. 6 psi, as you said, ain't it.

Years ago, I worked at a FBO in South Carolina. One Saturday, a customer came into the office, said he had cranked up his Piper Lance, and got an oil pressure warning on his annunciator panel. He didn't mention what his oil pressure gauge read, so I'm guessing he got spooked by the light coming on, as it's high on the panel and right in his face, and never actually looked at what the gauge was reading.

We towed the plane into the hangar and our guy connected a mechanical gauge to it and verified it was in fact a pressure issue. Our mechanics pulled the engine and sent it to an engine shop in North Carolina. A few weeks later the engine was shipped back to us and our guys hung it back on the airframe.

After an extensive ground runup, it was given to me to go test fly it. Five minutes into the flight, the engine failed and I ended up crashing, destroying the airframe and almost me as well. Took me a year and a half to recover enough to return to work. The plane never flew again, but I did. Cheated death again!

The cause of the failure? It wasn't anything the engine shop did. The Piper Lance's oil cooler is not an integral part of the engine but is actually part of the airframe, with a line running between them. The line had vibrated loose in flight and dumped all the oil all over South Carolina, leaving me holding the bag.

As for my emergency landing, I was doing great until I clipped something and ripped the left wing off. Then it all went to hell. But I digress.

If the OP drove his truck back to O'Reillys without it locking up, I seriously doubt resetting the computer by disconnecting the battery for a couple of minutes, then restarting it will do significant damage. And as the OP said, it worked. So not the best way to do things but it worked out OK.

 

Probably just a coincidence. The light might even have come back. No offense intended but the actual oil level was never mentioned. Might have also added a few quarts at some point.