Hi guys. My truck (2003 3.0) has been sitting in my back yard for the last 2 years because of an issue that has me stumped, and I really don't want to tear it apart any more than necessary.

The last time I drove it I lost oil pressure on both the factory oil pressure gauge as well as the Cyberdyne gauge I installed in a pillar pod. The truck seemed to run fine, no bearing noise for about another 3 or 4 miles.
After I got it home on start up I would have normal oil pressure, but after the truck reached operating temp the oil pressure went away on both gauges again. Shortly after I could hear bearing knock, so it was shut off ASAP.

Because it's a gearrotor pump I would think if the oil pump was TU I would not get any oil pressure. And because I am getting indication on both gauges (good and bad) it should a gauge problem (the electronic gauge is "T"ed right off the block, the other side of the "T" is where the factory sending unit is tapped into.
Oil and filter are both fresh, I saw no sign of Babbitt in the old oil.

Anyone have any good ideas? I don't want to use diagnose by parts replacement, but I am missing driving my lil 'ol truck.

 

You could remove one valve cover to see if oil is circulating. If there's any pressure at all, oil should be getting to the engine top and to the valves. If it's dry, then you'd confirm your doubts as to low or no oil pressure.

It does seem strange that you "see" oil pressure for a period of time, then it stops. You can try removing the "T" and putting the factory oil sensor back into the block; I'm concerned though that you did hear bearing knock, a good indication that you are loosing oil pressure.

The OEM sensor is only a "yes/no" indication of oil pressure. It sets the guage when it sees 6 pounds (i think thats the rating). If it does not, then the guage is dead. I'm not sure as to why Ford gave the guage anything in between (such as a "H" and "L" on the guage) as you'd never see the guage fluxuate.

 

Pulling a valve cover is not exactly a small task on my engine, and one that I would rather not do just for a fishing expedition. Check out the pic and I'm sure you'll agree.

 

I'll agree. I'm not sure of any other easy way to determine if you do have oil pressure, so the valve cover removal was an idea to check that oil was making it to the top of the engine, not intended to be a "fishing expedition". From the sounds that you described (mentioned hearing bearing knock), that would indeed indicate oil starvation, and at the earliest point of lubrication.

It's also difficult to remove the oil pan on these 3.0's, as it may be possible that the oil pump pickup is clogged. From the looks of the engine itself, it appears very clean and well maintained, so I'm not saying the oil was neglected.

What's the mileage on this engine? This may also not be a factor....I have over 215K on my 3.0, and the oil pressure is still good.

 

Thanks for the compliment! I'll hit the big 60 on my next birthday and turning wrenches is just not as much fun as it used to be. I think I would have to pull the supercharger and plenum just to be able to get to the motor mounts so I could raise the engine the "3 inches" to pull the pan and inspect/ replace the oil pump. I have to pull the drivers side wheel/ tire and use a combination of extensions and u joints just to change the drivers side spark plugs!
Guess I'm hoping, maybe in vain, for a lazy mans fix.

 

We are very close in age, and exact when it comes to how much work we want to do these days! My wife now says I'm "old", as I now complain when I have to do something as simple as the oil changes. I used to really enjoy tearing into an engine, but not so much anymore.

I do hope there's an easier way for you to identify the oil pressure issue. I'm interested. A very knowledgable person on this site is RonD. PM him and ask him to post his thoughts. I hope he does share if there's a way....

And at my age, the fishing does sound good. I just don't like it when something gets hooked; then I have to reel it in and re-bait the hook. Too much work!

 

What supercharger kit is this?

 

That is a Whipple kit, made just a month or so before they stopped making them.