So about a month ago I started to have a problem with my oil pressure in my 2000 jeep cherokee, I was told to change the oil pressure sensor. Did that. Than I was told to change the oil pump. Did that. And I was running, 5w 30 full synthetic high mile motor oil and that was like running warter through the engine (my neighbor told me and this is all comeing from a guy who worked on the jeeps from the 80's to 2000's at the dealer). So my neighbor recommended me to use 20w 50 motor oil and when I drive it's reading I have oil pressure(however the more I drive the oil pressure drops) but at idle it's about 10lbs of oil pressure and the check gauge light comes on if there is anyone who can help me figure this out than please HELP.

 

mileage of the engine? that is a pretty heavy viscosity even for these engines. they seem happy around 10w30 and if at a higher mileage rotella 15w40. also if youre skeptical the gauge is a dummy reading imo and use an actual mechanical gauge to verify pressure.

 

I wouldn't worry too much too you verify the issue with a mechanical gauge. You can check the resistance across the wires of the sending unit. Post those with photographs of the gauge at those times. Someone here may know the expected values.
Also, where what the guest for the battery is accurate. Compare a multimeter across the parts to the gauge at the same time. You could just have an issue with a slight amount of corrosion on the grounding for the gauge clusters.

 

Don’t take any advice from your neighbor he’s not your friend.