Sudden extreme drop in oil pressure

[86RangerXL]

I was leaving o'reilly's earlier and noticed my oil pressure was almost none so I immediately pulled back into the parking lot and shut it off. It was fine while I was driving before I went to o'reilly's. It still sounded like it ran how it normally does in the short time I had it running with almost no oil pressure and still started fine. No noises before this happened or nothing really. I noticed the past 2ish days I've heard a pretty infrequent pinging sound (imagine the sound when a pebble hits the floor of your car). No idea if that has anything to do with this, but I figured I'd mention it. When I finally got it towed home, I saw its dumping a good bit of trans fluid onto my garage floor, but almost no oil leaking at all (I've had a very small valve cover gasket leak for months). I checked the oil level 3 days ago and it was good, checked it again after getting home to double check, sure enough its still at a good level. I don't know how old the oil in it is, but when I got the truck 8 months ago, it looked like brand new oil and still looks pretty good. I've only driven 1.5k-ish miles due to a project, so haven't changed it yet (planned on changing it very soon). I doubt it would be the oil in it though due to the drop being so sudden. The oil gauge is barely above off when it was running, so its not like the gauge was on complete 0.

Basically, I'm just asking if anyone has suggestions. I think it could be the oil pump that failed just because of how quick it happened. Doubt its ever been replaced in the 36 years it's been on the truck.

 

[RonD]

Most likely just the oil pressure sender on the engine, it grounds the gauge on the dash

If you lost oil pressure you would have instantly heard the lifters all "tick, tick, ticking" its loud you can't miss it

The noise you describe seems like pinging/knocking, usually occurs when accelerating if octane is lower or you have a slight Lean condition

You have a 1986 Ranger but what engine 2.3l or 2.9l?

 

[RumPunch]

Absolutely agree with Ron D. Likely a sending unit. Pull sending unit out plumb in manual gauge and check. If you want you can unplug the coil wire to distributor to prevent starting just so we know the truck won’t run with low-no oil pressure. If you have pressure with a manual gauge then a trip back to that O’Rieleys and a new sender it is.

 

[86RangerXL]

Most likely just the oil pressure sender on the engine, it grounds the gauge on the dash

If you lost oil pressure you would have instantly heard the lifters all "tick, tick, ticking" its loud you can't miss it

The noise you describe seems like pinging/knocking, usually occurs when accelerating if octane is lower or you have a slight Lean condition

You have a 1986 Ranger but what engine 2.3l or 2.9l?

Turns out it was the oil pressure sender. Popped a new one in and its right back to normal thankfully. To answer your question before, it's a 2.9