2001 4.6L 4x4 with 104k mi.

Yesterday I went to leave work (cold start) and noticed that my check oil light was on and dummy gauge was bottomed out. After a few seconds it popped up to normal and the drive home was uneventful. Recent oil Motorcraft 5w20 oil change and FL820S filter. Oil is still clear and level in the middle.

This AM, 17 deg. cold start, everything was fine for a few seconds, then it dipped down long enough to trigger the check oil light, then popped back up like normal.

I just left for a late lunch, another cold start, and it started normally, but after a few the light came one, gauge bottomed out. It did this for maybe 5 seconds then acted normally, crashed, then normal again for the duration of my trip.

Does this sound like a failing oil sending unit or other issue? Anyone know where the unit is located? Is it possible to replace the factory 2-wire with a 3-wire that reads actual oil pressure, or is the harness not setup for it at all? Thanks!

 

Sending unit switch.

 

If you are not getting any rattling or knocking from the engine when the gauge drops off then it's the oil sending unit located next to the oil filter on the oil filter adapter, easy to change.

 

Thx guys, surprisingly it didn't do it this AM @ 4 deg. F.