Warning light came on twice at hot start. Just brief, flickered and off. Couldn't find a oil pressure tester so hooked up a cheapo mechanical gauge. Cold idle 25, cold 2000 rpm 50. Hot idle 8, hot 2000 rpm 40. Haven't had the truck long but it was rebuilt by British 4x4 in NC 20k miles ago with the previous owner. Truck now has 120k. Thinking the next step is to pull the pan and front cover to see what happened. I changed oil 1k ago with 10W-30. I realize after reading here 10W-40 is preferred but regardless, thinking my issue is more serious than my oil weight choice.

Before doing so any other thoughts on what is happening or what I should be looking for?

**changed to Rotella 15w-40. Hot idle 9 psi, hot 2000 rpm 34. Numbers just before with 10w-30 hot idle 7 psi, hot 2000 rpm 26.

 

was your oil level normal or low? If low, the light will show up opon start but other than that, might be more serious thing.

 

What did the rebuild include? Would be good to know what parts were replaced and if pressures were recorded after. Regardless, pulling the pan and cover is a good start. Many have found cracked pump gears and/or clogged pickup screen. If the pump was replaced, maybe they got cheap and did not replace a scored front cover? Beyond that, could be a cam bearing but I think that usually results in lower numbers than you are seeing.

For ref, I run T4 15-40 and have 50+ cold idle, 20 hot idle and 50+ at hot 2K

 

Yeah 15w40 is the preferred, some even going to 20w50. Non synthetic.

 

Oil level was fine. Anyone know the specs? I was told mine is on the low end but ok. I'll follow up with the rebuild shop but they said it was a full rebuild and done right - top hat lingers, valves, cam, etc. Runs excellent with no ticks.

 

what oil filter did you put on it?

 

It's a fram filter (I know, can imagine the flaming already haha). But even so, thinking it can't impact the idle pressure that much or am I thinking of this wrong? Found out the prev owner has had an intermittent warning light (he tells me 2-3 times but assume that means more) at hot idle start up ever since it was rebuilt but he never followed up with the shop or checked pressures. I have owned the truck since early July and have driven it 1200 miles. This is the first occurrence of the warning light under my ownership.

 

I just bought an 04 with a similar issue. Runs awesome no ticks, but once warmed up the oil light will come on after the idle gets below 700RPM. Engine never changes it's sound (zero ticking/knocking). Already ordered a new oil pump kit with gaskets, pick up tube o-ring, and oil pan gasket. Plan on dropping the pan first inspecting the pickup tube, and o-ring and if I don't see anything wrong I'll remove the front cover.

 

only time I had a flickering oil light was fram lol

 

Your cold start pressure is fine, because at cold start the first number of oil viscosity is at work which as you stated using 10w30, but when it's warmed up the second number which is 30 and will bleed out too quickly from bearings & oil pump, b4 you tear anything apart use a good quality multi grade oil of your choice that second number is 40 & see if you see a change in hot start up,, it should be 10 psi idle & 50 psi at 2000 rpm,,