There is no question. It is the relief valve in the filter base. Items 74 and 75 in the picture are sticking and not controling the pressure. The oil pump is a gear in gear excentric type pump inside the timming cover and runs on the crankshaft. That pump will put out 200lbs without even thinking about it. In sub-zero weather like we have around here, it can pump twice that.
Pull the filter bracket and clean all the ports and free up the spring and plunger. Be careful taking it off because if it is working a little, it may pop out and smuck you in the forehead with the plunger and the spring will head straight for the floor drain in the garage. Or it will land in the breast pocket of you shirt and you will spend hours looking for it and then find it a couple days later. But only after you have gone to town and bought a new one, using your woman's car for which you catch hell because of the grease spots on the seat and carpet.
Now, to prevent this in the future, Change the oil and filter at least every 3000-4000 miles with regular oil (not synthetic) and use Slick 50 every 4th oil change. I have had 87,89,92,95,99,02,and 04 Bonnies from new to 300,000+ on every one of them. Had to replace the tranny in the 02, but other than that nothing. I sold them and bought new because of what used to be called the 100,000 mile syndrome. Switchs, knobs, door locks and hinges, window motors, door gaskets, windshield and rear window leaks, trunk locks and hinges, heater controls, headlight reflectors rusting, electric fuel pumps. I took the engine/transaxle, suspension and "H" frame from the 89 and put it in the back seat of a 72 beetle. I was going to re-design the front steering because it got real squirrly above 130mph but my son lost it through the ice in 600 feet of water on Lake Michigan. He is Ok but his girlfriend dumped him because she was wearing a $200 bridesmaid dress and had to shuck it because it was dragging her down. The other kids that were racing with them fished them out but nobody thought to mention it to me until the next morning. Something about sleeping it off! It took me 2 days to find where they went through. By then there was 2 feet of ice, so I just left it and made him ride the school bus until graduation. Besides, the DNR would have charged me a couple grand in fines and recovery fees.
Well... enough. Good luck.
