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When you look inside the engine block while running what should the inside look like?

Haha, but seriously what year and model? I had an '88 740 that lost a huge amount of wire insulation, every injector wire and that oil pressure sensor wire was completely bare along the base of the block. The only reason it ran was because there was a ton of grime insulating the wires lol
 
Awesome advice from everyone thanks.

That's essentially what I just came across online -
https://www.justanswer.com/volvo/1b9as-1991-volvo-740-oil-pressure-light-on-restart-knocking.html

The guy said his problem was a broken timing belt and had nothing to do with the oil, but otherwise the mechanics response sounds tailored to my set of particular problems with the oil. My car has shut off several times while driving it, but then turns right back over if I turn it completely off then on again. Sounds like my sensor is going wonky.

This sounds like my problem again except I've had no maintenance done to my head gasket or camshaft oil seals that I'm aware of -
https://www.matthewsvolvosite.com/forums/viewtopic.php?t=42014

This part sounded most interesting -
"There is a relief valve spring in the oil pump. If this is sticking the same symptom can occur. "

This also might explain my errant oil sensor light, although it's much more full on flickering now then faintly appearing for a while and going away. Still goes away for a bit though then comes back.

Would also explain that why my car auto shuts off while driving.

Found some interesting links pertaining to the oil pump removal/replacement, though they could be better - http://www.volvotips.com/index.php/740-760-780/volvo-740-760-780-service-and-repair-manual/
http://www.volvotips.com/service-manual/volvo-740/Volvo-740-760-780-940-960-B204-B234-16valve-engine-service-manual.html
Page 60 describes how to take out and replace the oil pump. Hopefully it's just the sensor that I'm having problems with though.

So my first step is to check the wiring and sender, see if its loose or something. Replace the sender.

Second is

to test the oil pressure!

Looking for diagrams online to find where the oil sender/sensor unit is... Can anyone direct?

- My advice; stick with this site. Your getting way to much info and its all over the place. Id almost bet money that you have some wiring problems. But you need to let someone here help you trouble shoot step by step. Everybody is waiting for your year and model. Makes a difference.
 
Forget the wiring- put a liquid gauge on it to rule out the electrical/ gauge/wiring FIRST.
While you are putzing around assuming it’s electrical, you may be exposing your engine to a dangerous low pressure condition which could turn it into a boat anchor before you complete your diagnosis.
 
But you need to let someone here help you trouble shoot step by step.

While you are putzing around assuming it?s electrical,

Guys? 4 posts back...

long story short I bumped some of the crusty wires beneath/around the alternator with my hand and wiggled one that was grounding to the engine block. Oil pressure light was no longer lit,

Electrical it is / was,

PHEW I hope that light never comes on again...!
Actually, you DO want it to come on, but only when the key is in the "on" position, but before the engine is running. That tells you the pressure switch and warning light are both working correctly. Once running, the switch should open up due to oil pressure and turn the light off.

Replace or repair the "crusty" wires, and make sure they have a clean, tight connection to wherever they all go.
 
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