Sudden loss of oil pressure, need advice. (1 Viewer)

[Archengine]

Well, a quick background, I have had good oil pressure for 7 years or so, roughly around 14 lbs per 1000 rpm at operating temperature. Yesterday, I went to Slade, Ky, spending roughly 12 hours or so comuting and on the trails with little problems regarding oil. On the ride home, I noticed I was only getting around 20 psi at 2300 rpm, which seemed low, but the engine was working hard all day. When I pulled off the highway, my pressure dropped to zero, and before I could react and shut off the engine, it stalled on me. So, I started up the truck after letting it sit for 5 minutes, and pressure is zero at idle, but around 15 at 2000 rpm, so I left the truck. This morning I went back to tow her, but she fired right up like nothing ever happened, back with normal oil pressure, so I drove her home, and let her idle for a while, to make sure she got up to operating temps in both the coolant and oil. Works fine now, so what gives, is my pump on the fritz? I can't imagine an oil pump would take a break, and then start working again. What do you think? Thanks

 

[Jukelemon]

Hey Arch. Wish I could have been there! As opposed to a pump issue maybe it is a sending unit issue. Is it stock? I know we had this discussion a while back when I was considering getting an aftermarket oil gauge (by the way, my issue was the wire had clome off of the sending unit. Put it back on and, bam, pressure reading).

 

[Archengine]

I have both the factory, and a mech. Autometer gauge hooked up on 2 different areas, and both of them dropped to zero.

 

[Jukelemon]

ouch. Well, so much for the simple answer.

Well, first, I have never been in a circusmstance of running an engine with no pressure but it seems the stalling would be unrelated. In the worst case scenario, wouldn't the engine freeze not stall if there was excessive damage/heat build up? Well, both gauges are electric right? Maybe the stall and lack of pressure correspond to an electrical failure of some type.

 

[Archengine]

Unfortunately, the Autometer is a mechanical gauge, so it's just plain odd, makes no sense to me.

 

[Jukelemon]

You got me friend. Maybe that is a consequence sometimes of long term, slow revving engine performance (four wheeling)and then highway travel. Puzzling.

 

[offcamber40]

Could it be possible that something lofged in the pick-up on the pump in the pan, then after sitting overnight it settled? This is puzzling.. Sometimesw if the distibutor comes loose and pops up you will loose pressure as it is driven by the dist.. it may be why it stalled too? Good luck,

Mike

 

[Archengine]

Never thought of that, offcamber, but the dist feels solidly on. I also thought about something being lodged in the pickup, and blocking the flow at idle, and with higher rpms, then it was able to leak past it, which would explain the low pressure compared to normal at speed.