Oil pressure gauge is jumping up and down and then it loses pressure then itll come back and jump up and down again no knocking or noises

Do you know what a knock sensor is ?
The knock sensor (KS) system enables the control module to control the ignition timing for the best possible performance while protecting the engine from potentially damaging levels of detonation. The control module uses the KS system to test for abnormal engine noise that may indicate detonation, also known as spark knock.
If the control module has determined that knock is present, it will retard the ignition timing to attempt to eliminate the knock. The control module will always try to work back to a zero compensation level, or no spark retard. An abnormal KS signal will stay outside of the noise channel or will not be present. KS diagnostics are calibrated to detect faults with the KS circuitry inside the control module, the KS wiring, or the KS voltage output. Some diagnostics are also calibrated to detect constant noise from an outside influence such as a loose/damaged component or excessive engine mechanical noise
Do you know what spark knock is or pinging ? EGR valve problem ! Is your oil pressure low ? do you have a gauge or a oil light ! If it where an oil pump problem the light would be lit ! Is your check engine light lit ? How many miles on the vehicle ? Timing chain an gears , jumped time !

cold oil is thicker, higher rpm=more pressure .factory guage is actually working like it should. if worried hook external guage on oil galley plug and check oil press.manually.

if you ran out of oil and you now can hear knocking sound comming from the engine then it time to get it checked by a mechanic

Tough to say. The lifter making the noise could be allowing oil pressure to escape. Or it may be dry for oil because oil is not getting to it.
You may have to take the lifters out to see if it is a lifter problem or lack of oil.

To start, take the vehicle to a dealer and ask them to screw an oil pressure gauge into the block hole and check your oil pressure whilst idling and while driving it.
I have a 1993 and it does the same thing, but the problem is only the gauge itself.
If it is actually having such oil pressure fluctuations, you may have a defective pump, a clogged pump filter screen, or a clogged oil filter.
God bless your efforts.

Before driving it anymore I would have someone test the actual oil pressure using a mechanical test gauge to see how much , or little, oil pressure you actually have. The knocking noise could be a hydraulic lifter that is partially collapsed due to low oil pressure or a rod bearing that has been damaged from low oil pressure. If it is just a lifter that is making noise then there's a pretty good chance that the lifter will quiet back down once the oil pressure is normal again. If it turns out that your oil pressure is normal both at an idle and at highway speeds then the noise may be unrelated. You can cause some serious damage by continuing to operate any engine that is low on oil pressure even if the dipstick shows it to be full of oil. Hope this helps and good luck!

You probably have a bad sending unit for the fuel level in the tank. this would cause the gauge to be erratic when the level is below 1/2 tank and the float is moving around much more than when full. The oil pressure gauge problem could be caused buy a loose wire connection or a faulty sending unit.

Oil pressure gauge is not getting good ground. Check wire.

First thing you need to do is put a mechanical gauge in place of oil sender and read actual oil pressure. If mechanical gauge shows same condition, take a look at the connecting rod bearing serving the cylinder where the valve bent. If the piston hit the valve hard enough it may have created a flat spot on the bearing that is permitting oil to bypass the bearing, That won't knock right away because the bearing is still supporting the rod, unlike when the bearing bore has worn all the way around, and is loose. Bearings are made from soft metal, so that they can absorb a certain amount of dirt without damaging the crank. Being soft, they can easily be deformed.
If mechanical gauge shows no problems, just replace the original sending unit with a new one..

I had the same problem with my 97 Wrangler 4.0..Change your antifreeze, replace with some new 50/50 mix...Also chanke your oil, replace the filter with a mopar filter and use stratght 30 weight motor oil...Solved my problem