oil pressure fluctuations
 

so ive done some watching with my oil pressure gauge this year and now have some new concerns.
ive went from 0w20 to 5-30 with little changes in pressure. On poconos this year i had a whopping 40psi max the entire time at around 235 degrees oil temp.
idle seems to always be at 0-2psi at 208 degrees my city temp thats until i went 5w40 Total energy 9000. Instantly after the change ~10psi was noticed across the whole range at normal op temp. Idle was at 12-14psi, 2.5k was at 40psi, 3k was around 50psi and went even higher as i climbed the band things were great.
Now fast forward to the present i have 2700 miles on the oil and noticed the idle to be back down at 0 psi last week, cruising had dropped down to ~45psi at 3k.:iono:
so i check the oil level and i was about around 85% full. i remember it being a tad over full so i just add a bit and bring it up to spec suspecting some weird cavitation issue that no new car should have. Now today 3k cruising was down to about 35psi, 2k was down to 20psi and i was reading 0 psi until 1200 rpm which has never happened so what ideas do you have?? Did the oil break down, is my pump failing or is the fa20 just being shit and i am going to have to go buy a turbo mustang?

maybe? most likely the pump, the fa20 isnt exactly shit, dont buy the mustang dear god im begging you.

When I first start the car in the morning with temps around 20 to 22 deg C at idle pressure is 85 to 90 and quickly drops as heat builds and goes to 0 at idle and shows 1 or 2 at 1200/1300 rpm same as yours.

It's something that does concern me a bit but it's still running and going well with about 15,000K on the clock so :iono::iono:

Are you measuring oil pressure from the ecu or from a standalone sensor?

Standalone but not sure how accurate it is so going to replace the sender unit with a VDO one I've got and see if it makes any difference as I thought start up pressure would be a bit higher .

Ya it's below 0 deg C here right now. It use to always jump to 10psi by 1000rpm but last time i checked these specs were correct acording to factory manual. Im at 27000 miles tracked and dailied over the last 2 years so i mean its holding up lol

A standalone sensor which im considering may be faulty. Ive checked the wiring and connectors for rubbing and corrosion but its all good so maybe the sending unit is bad. Today i was holding a steady 2700 rpm and the thing was bouncing between 44 and 49 psi then i went to 3 k and it dropped to 40psi steady. Wierd

I vote for faulty sensor

I may have to look into that. Only a yr old sensor. Smh

My Greddy sensor has taken a crap in the last couple months. Most of them are all the same and can go bad. If I was driving around the amount of time it thinks I'm at 0psi the engine would have seized by now.

Where is the sensor installed? Could it be it isn't seeing the full pressure? Or mabey the pressure relief valve is sticking?

its at the port right under the intake, direct pressure from the pump, since day one it read very well and was in factory specs at the given temperature. only recently its started this while on the heavy weight oil. The gauge has been very bouncy these last 2 days so i think its the sensor. Its never bounced around before.

I think you'd be game over with 0psi at idle, oil pressure light we be on constantly.

you would think but all fa20s are at 0psi with 0w20 or 5w30 oil. Oil is still flowing just not pressurized enough. makes me think the oil light doesnt really work lmao