I have a 99 Ranger 3.0L 4x4 XLT. The pressure gage is fluctuating. The engine had been running rough prior to the gage problem. I've replaced the oil pressure sending unit. After warming the engine up the gage still bounces around while idling in park. If I give it a little gas or put it in drive the needle reads normal. Not sure if I should check the Cam Position Sensor and shaft next or test for oil pump pressure next? I've read a lot of the threads here and I'm pretty sure the prognosis is not good but I like the truck. I'd hate to get rid of it. I've recently replaced the head gaskets and had the transmission rebuilt.

 

replace the camshaft sync

 

Is Cardrone a good part or should I stick with Motorcraft?

 

motorcraft only

 

Did you replace the sending unit with the factory original sending unit or the upgraded one that reads actual pressure? the stock unit is just an idiot light really it reads a set PSI and puts the needle in the center. If you bought the upgraded one then you also have to bypass the resistor on the back of the cluster to get it to read correctly. From your symptoms id say the synchronizer is the source of your rough idle but if the gauge is moving id say you got the aftermarket sending unit but have not bypassed the resistor so it doesn't know what to do with the signal its getting from the sending unit.

 

Is it posible to not engage the oil pump shaft whem stabbing the sychronizer shaft. I went from a fluctuating oil pressure gage to no movement at all pegged to the low pressure side. The new sychronizer shaft is seated all the way no gap. There was a lot of sludge on the old sychronizer. The gear was worn but no teeth were missing.

 

I'm having the same problem with my truck. Please post on here if you fix it! I have no idea what to do about it.

 

What have you tried so far?

 

Nothing yet. The guy at napa told me to get a gauge and see whats going on. But I don't really see how that is going to help

 

I'm going to take apart my old synchronizer shaft and make a oil pump driver that will go on a drill and see if I can get the gage to move that way.

 

Mine only does it when it's warmed up, not cold. Is that how yours is? And when I turn the motor off the gauge stays put and goes back to 0 very very slowly. I'm going to start by disconecting the gauge from sending unit. See if the gauge drops or not. If it does drop I'll replace the sending unit. After that I have no idea. I guess get a gauge and see what the pressure really is.

 

Mine was bouncing back and forth between high and low when I came to a stop. It seemed to start once the engine was warmed up. I changed the sending unit and it had no effect. Next I changed the sychronizer and now I have no pressure at all. It's in the single digits temperature wise here so I've put the project on hold for now til it gets a little warmer. I'll let you know what happens. The 4.0L motor is a little different than the 3.0L keep that in mind.

 

Low oil pressure mystery solved. Call me stupid I deserve it sending unit was un plugged.

 

Mine was just the gauge!

 

Kasey, my gage went 2 days with out flickering then started all over again. I'm going to try just letting it go. I'm pretty much convinced its the gage or an electrical problem. If it truely was low oil pressure my motor would be toast by now.