Cold idle 46
cold 2000-2500 RPM 48-50
Hot idle 14-15
Hot 2000-2500 RPM 40

Even at 4K RPM it wont go pass 42-43 when hot

Are these numbers ok for a 2004 D2?

And is it normal to not have any oil check light when the switch was off the car for pressure testing? I thought my oil check light will come on.

 

Yes, your light should be on, BUT only if you touch the sensor to ground (bare metal). The sensor is a single wire normally closed switch, when pressure is applied it opens the path to ground. Yes, it should also come once every start and stay on for a few seconds until pressure builds above 7 - 8 PSI. In cold weather this takes longer and use of synthetic (like 5W40) will make it happen faster.

My interpretation of your numbers (which is worthless, but they look like mine) -

At cold start the oil is thick, and the pressure differnce inside the oil filter pushes a spring loaded valve. Oil flows at maximum performance of the pump at idle or revved up. There is no loss thru the filter, because it is bypassed.

When oil warms up, pressure changes at idle, and bypass valve in filter returns to normal. Oil has to flow thru filter media, and there is a small pressure drop, so idle and revved up PSI changes. Idle changes even more, because oil is hot and thinner.

You are above spec for idle hot, which is good.

Your cold reading of 50 shows pump is capable of 50, but your oil type and your filter type may be holding this back. See tech sticky https://landroverforums.com/forum/di...estions-46975/ for some types of filters that have less constriction. You may want to change oil and filter and repeat test. A D1 4.0 engine and a D2 4.0 have the same block, and the same oil pump. But the D1 spec warmed up is 30- 40 PSI revved up. You may also have wear in bearings that makes the pressure a little lower.

 

Thank you Savannah Buzz.
I have one of those monster purolators in the trunk of my car waiting to be put in sevice during next oil change.
Now that I know how to check the oil pressure will repeat it again with fresh oil and new filter next time. I have rotella T6 in there and stocked up on both dinno 15-40 ($13 at adavnce) and synthetic 5-40 ($19.99 at advance) Since weather is getting warmer in MI, should I put the 45-40 or stick with the synthetic.
The one wire at the switch scared me first, thinking I ripped it off. I actually unbolted the bolt with the sensor wire attached, but than saw that the plug had only one lead inside too, just didn't know about the ground contact for it to get activated.

 

If you are above 20F the 15W40 should be fine. You could also change just filter now, just pour a quart into it.

 

Like Buzz said those oil PSI numbers are fine.
Switch to the 15w-40 for the summer.

 

I would drain and change, the t6 oil is pretty thin plus two bottle of white Shepard might dilute it even more. Maybe this is causing the grinding noise.