97 Ford 150 4.2L V6 with 130,000miles
When engine idles the oil pressure gauge goes down to almost zero and then oil light comes on? I am running 10W-30 and have a multiple part question.
1. Will changing to 20w-50 help without posing too high of a viscosity?
2. Where is the oil sending unit located?
3. Can the oil pump be changed on this 4x4 without pulling engine?

Thank you and have a blessed day, PdMAnalyst

 

at this point what could happen if you did change the oil? i dont see how it could hurt anything. the sending unit is on the front cover above the oil filter. the oil pump is where you screw the oil filter onto. remove the filter and you have six bolts bolting it to the front cover. have not seen many of these pumps go bad but have seen alot of pickups stopped up and engines sludged. good luck

 

I had been running 10w30 and having this problem after the engine got hot. I changed to 20w50 and the problem is corrected. When it comes to Cold Winter months I might go to 10w40 but the problem is fixed and pressure is rock solid. When you pump X amount of volume with a lower viscosity oil and you less less resistance to flow within the engine that equates to lower pressure, so I can't close up the clearances without an engine rebuild so I just changed viscosities.
Always remember this, a pump pumps volume and resistance to the flow of this volume creates pressure.
97 F150 4x4 4.2L
98 Ranger 2.5L