high low as in jumping from one temp to another is what a bad pressure sensor can do. as the engine heats up its not unusual to lose 20 lbs across the board

 

Yeah but I start out with 40 and end up with zero.. That's a retry big drop.

 

what brand oil filter is on it?

 

Check your actual oil pressure with a mechanical gauge, or replace the oil pressure switch. I've had a bad switch cause what you're describing, and it scared the crap out of me as I watched the gauge go lower...lower...lower as I drove. The absence of terribly noisy lifter clatter (what you will get at 0 pressure) helped to keep me more at ease. But still, get it checked out asap.

 

69, I got the clatter though.

 

Are the lifters/rockers quiet until the oil pressure starts dropping, or are they noisy the same either way?

 

Oil pressure drops, clatter starts. The I turn off the car, wait a while, turn it back on, oil pressure goes back to normal.

 

Jake............................if you don't know how to do it yourself, please go get it checked. You are playing a dangerous game of speculation. You have no clue as to whether or not the engine really has low oil pressure. That is the first thing which must be verified.

If you have towing insurance, get it flat bedded but tell the ins company it won't start.

The one thing you must do is stop driving it and stop running the engine except to put the manual gauge on the engine.

clatter, no clatter, when did it start clattering is all moot at this point. You've been given the first step, please follow it. I hope it's simply the sensor itself because if the car does have low oil pressure, it's not going to be the oil pump.

 

Trust me torque I know when not to run my engine. I'm just trying to get an idea on what could cause this problem. I know that it gradually loses pressure, and I know when it first starts it has more than enough pressure. So now I just have to pinpoint the problem.

 

That's an oil pressure (or lack thereof) problem. An inaccurate gauge, or a bad pressure switch isn't going to cause the lifters to clatter. From the looks of it, it appears your gauge may be telling you the truth, or close to it anyway.
What viscosity oil are you using? You can see if a higher viscosity oil will change the symptoms for the better. If so, you're experiencing serious bearing wear, and the "thicker" oil will help to mask the problem....for a while. Otherwise, it could be a bad oil pump, which may have already been mentioned.