I think it is possible, who knows what previous owners did or did not do. THats why I did repeated oil changes with filter. I even went to the point of cutting the filters and checking as well as flushing the filter media and checking contents visually and with a magnet. First filter off contents of filter looked like total crap, second better third filter liveable. Prime reason i did the synthetic was composition of the oil could change flow rate thru the crud and help in flushing. Side note is the 3.9 in the 89 has fantastic oil pressure always did, 5.2 pressure is always lower but a lot better than when I got the truck.

 

I havent looked to see if its possible with the engine in chassis. But instead of spending 30 bucks every 600 or so miles, look and see if you can drop the pan and clean the pan out at least. Maybe clean off the screen on the pickup tube. Or change the oil every 600 miles if thats not possible.

But the sludge can most definitely cause for low oil pressures. I know my oil pressure light comes on when its time to change the oil. Its on right now, and its time to change the oil!

 

Sometimes the juice ain' t worth the sqeeze. 4x4, winter, no garage, no lift naaa, ill spend a little always and try the easy ways first. I have experienced filter clog problems. I have had the best filters, in other words high priced reputable ones get crud in them and pressure drop.I have also had the experience of a truck dropping when the frozen gravel shifted, jack stand sunk and truck came down. Sometimes its better to spend a buck than take a chance.

 

I just am at a loss here. You can see this video the pressure is a little better. It doesn't just completely fall when put into drive but it still gets low. Perhaps my sending unit is still clogged with gunk? If that can even happen. I've check my nearest parts store that has had all my parts for my 87 Ram they don't have the sending unit, just the "Oil Pressure Switch". It's 16 dollars is that what I need or do I need the physical sending unit?


http://www.youtube.com/watch?v=qHjU685yOHM

 

Your oil pump is going bad, I would bet on it.

 

That is just a bad oil sending unit. Replace it.

 

So while I was trying to install the new oil pressure sending unit I had taken the air filter housing off to give my hand somewhere to rest. Turns out I completely snapped an old hose right off the front of my throttle body. I believe it was the Idle Purge Vacuum Line. So I went up got some more hose (Fuel line hose to be exact) and put it back together. Can anyone give me any information on what this vacuum line does?

Also was it bad to use fuel hose to put it back together? Should I be worried about excess heat in that area?

I'll give the oil pressure sending unit another try another day when it isn't 15 degrees out and I can actually feel where I am placing my hands so I don't snap anymore vacuum lines.

 

LOL any hose is better than no hose. I would use it if all I had. Looking at your o/p video I also would disconnect the coil and crank the engine for a few seconds with something to deflect the oil to the bell housing like cardboard or whatever to let the O/P chanel blow crap out then install the new sender. Cold weather I spent all day outside working yesterday never got over 18F. You gotta do what you gotta do. Ill be putting CPU temp sender and emergency brake cables on today,( if Mrs N. doesn't come up with one of those fantastic shopping trips women plan and launch on us). Outside and right now it is by the weather report 9F, but my thermometer says 6F. Yep I will wait for the sun.Right now I gotta get the dogs back in so they dont freeze and let the out of her box. Have fun.

 

There should be a vacuum diagram under the hood.

 

2 Things:

As was stated before, put a mechanical gauge on it. See what it says straight from the block. That way the sender, the ecu and gauge itself are all taken out of the question.

If you don't have a gauge or can find one and you do just replace the sender, then get a quality one, don't cheap out.
AND, while the sender is out, disable the fuel [this is very important, obviously ] And turn the truck over for a bit. If the engine was carbon'd up or gunk'd up, it's possible there is garbage in the oil passage leading to the sender. And cranking it with the sender out will pressurize that passage enough to clean it out.

That may not be your problem, but it also could be. I've seen it happen and it's worth a try.