I request wisdom (Lost Oil pressure)

[DarrenA]

Hey y'all. So I took the truck to work one day and when coming back home I noticed the oil pressure gauge dropped to the floor out of nowhere. Pulled over, checked for new leaks, checked to make sure oil was still present, tried to look through oil fill cap into valve covers to see if valve train was still properly lubricated. All seemed to still be normal. Assumed sender finally went out. I replaced the sensor and same result. Must be messed up wiring, right? Continued to drive to work for a week in the thing, including interstate driving which ya'll know the 2.8 has to scream a little bit to make it up some of the hills on the interstate at a decent speed. If oil pump wasn't working then the engine surely would've started knocking at the least, right? Moving on, Fords oil pressure gauge is fake anyway (goes to middle as long as 5psi of oil pressure is present) so decided to add a mechanical oil pressure gauge. So here's the kicker, after I installed that and try to test it out, no oil fills the line...no oil pressure... Gauge was seemingly correct. I removed the oil pressure sender adapter from engine block and made sure it wasn't clogged in anyway, I did the same for the hole in the block. Still no oil in the line. Attached gauge lines directly to block. Still no oil.. I'm stumped, how has the engine not blown up yet? The thing still sounds fine as the day I got it running correctly again about a year ago now. Any recommendations or something obvious I missed? Oil level is good, engine sounds fine, perfect operating temperature, but seemingly no oil pressure.

 

[SenorNoob]

Is it possible there is a clogged passageway in the block going to the sender? Pipe cleaner thru the block? That's weird.

 

[DarrenA]

That's pretty much my only hope to avoid pulling the engine. All I did today was wiggle a 3-4in screwdriver around in there, maybe it wasn't long enough to clear the blockage? Makes me wonder what the bottom of that oil pan looks like. I'd like to rebuild eventually but when I have more than a gravel driveway to do so. If that don't work, I guess I'll take the valve covers off and really see if oil is getting to the valve train. I just refuse to believe with how much I drove it after the initial gauge drop that it really has no oil pressure.

 

[alwaysFlOoReD]

Could you get an airline up there and blow into the block? I'm not sure what oil passages are there but if you can do that then drain the oil.
Perhaps run some marvel mystery oil or trans fluid for a bit to help clean inside? About 1/2 quart of trans fluid for 1/2 hour, then air, then change fluid.

 

[DarrenA]

Not a bad idea, it'd be tight, but I bet I can squeeze an air sprayer in there. I'll give that a try with marvel, alongside the pipe cleaner and new oil. I put a quart of marvel in there last oil change, maybe it knocked some old crud off somewhere and it finally found a way to block the passage. Would also explain why it was such a sudden drop on the gauge. The more I think about it, it would be impossible for this thing to have fully lost oil pressure, the engine simply wouldn't have made it this far without seizing. Especially considering the way I wail on the thing.

 

[85_Ranger4x4]

FWIW my 2.8 was a very low oil tolerant engine... with mechanical lifters it will be reluctant to make valvetrain noise like a more modern engine with low/no oil pressure.

 

[DarrenA]

Interesting, mine has a slightly loud valvetrain even when I purchased it and the gauge was reading oil pressure. ( No different sound from now) The research I did led me to believe it was normal. With how much I drove it, I'd expect knocking if it was actually oil starved but I certainly ain't an expert.

 

[85_Ranger4x4]

Interesting, mine has a slightly loud valvetrain even when I purchased it and the gauge was reading oil pressure. ( No different sound from now) The research I did led me to believe it was normal. With how much I drove it, I'd expect knocking if it was actually oil starved but I certainly ain't an expert.

Solid lifters are slightly noisier than hydraulic lifters, that is one of the reasons they became obsolete.

However when hydraulic lifters are not fed with oil pressure they collapse and make a bunch of noise. Solid lifters won't really care... not near as much as your bearings which will suffer in silence until something major happens.

Ground it until you get the oil pressure figured out.

 

[DarrenA]

Ah good to know, yeah it ain’t moving until I figure this out. Fortunately, I haven’t driven it at all since that one work week. I’ve been lifting it, doing body work, fuel pump replacement. (She hates my wallet) Actually, only started it for the first time yesterday after the fuel pump install. Engine still spins quite easy, hoping all my bearings and piston rings are spared from destruction but we’ll see.

 

[SenorNoob]

Isn't the pressure sender/switch NPT? If so I'd thread a quick connect directly to the port. 125 PSI should clear a clog pretty quick.

 

[DarrenA]

You’re saying using like a pneumatic fitting for air tools and a hose, running directly from a compressor into the engine block? Yeah, it could be the same, I got some quick connect fittings lying around I could try when I’m not working.

 

[SenorNoob]

You got the idea. Make sure you leave the oil cap off so it doesn't blow out every seal in the engine.

 

[Uncle Gump]

I think i would pull the sender and if there is a restriction... try to let oil pressure push it out opposed to blowing that restriction deeper into the engine.

Maybe try spraying some carb cleaner or the like into the port to try and free things up beforehand.

 

[85_Ranger4x4]

Might slip a valve cover off and see if the top end is getting oiled while it is running. If it isn't then it isn't just a restriction at the sender.

 

[DarrenA]

Pulling the valve cover off is going to be the first course of action before I really get into it just to be sure. I tried spraying some carb cleaner in there before I started poking around a screwdriver in there yesterday to no effect. Even tried using the gauge line like a straw to try to clear it out. If it truly is oil starved and ran this long, this engine is a legend.