Hmmm.... this is exactly why I got the gauge and posted this. I have no clue where to start looking though. Everything I could think of in the system is new. The following parts are around 15,000 miles and maybe 1.5 years old:
Radiator
Water pump
Head gasket and all associated gaskets and such.
Thermostat
Hoses
Coolant (green)
Belt (proper tension on it)
I replaced a couple other hoses as well, had flushed the system, bleed it, etc.
I will check on the wiring for the fan right now, as well as the blades. If all looks good there, should I maybe start by getting a new sensor for the temp? The idiot gauge warms up like normal and stays in the middle, so I am wondering if that is the same reading.

 

Well, it was 42 here this morning, so 46 might be ok. But - when I unplug my coolant sensor, it shows -40 F, so there must still be some detection range left. The coolant sensor is basically a calibrated resistor, so it could be defective, cracked internally, separate at cold temperature, etc. There is a resistance chart in the pdf above, you could check with an ohm meter when cold, like whe you do the weekly fluids level check. Th factory gauge is driven by the ECM directly, so what ever the programmer geek decided was an acceptable range wil stay right at 9:00. When it moves up slightly, IMHO, you are already past the high end of the normal range.

On the other hand, we are applying digital technology to a mechanical engine designed with slide rules. We can monitor with high accuracy, but the mechanical meltz-da-waxx thermostat is not going to be exact every time, and will certainly exhibit some overshoot when first cycled for the day. The ultra gauge allows us to see this, and decide what to do. I think the D2 system, where stat "activation" section is not inside the engine block, and depends on hot water passing thru four small sampling holes, has some potential risks.

 

Here's a plumbing "map" for the D2. And I don't know just how messy taking the stat out is, but you'll need a tub. Have seen some vise grip pliers with long snouts set up for squeezing a radiator hose closed. But with my old rotten hoses that might cause problems as well. Don't know if you had a stat trash problem if back flushing it and cleaning out those holes would help.

and re: stays in the middle, so I am wondering if that is the same reading

From the RAVE:

The ECM supplies the instrument cluster with a pulse width modulated (PWM) coolant temperature

signal to drive the temperature gauge.

So the gauge shows what the ECM is programmed to show for temp X to temp Y. Scanner reads raw data before smoothing sub-routine is applied. Kinda like a "anti-slosh" circuit for a gas gauge.

 

Interesting stuff Buzz. Helpful for sure. I'm off to check a few things right now and we will see.

 

I wish the engineering budget had been shifted from "alarm" to "instruments". If we had instruments that matched the capability of the security system, it would look like this Skunkworks special: (Lockheed SR-71)

 

OK. So the fans seem to be pulling the right way, Aux fan comes on and functions like normal and everything else in the cooling system looks up to snuff. My money is on the fan clutch here. I did notice some of the fan blades have some chunks out of them, but not enough in my opinion to make that much of a difference. Looks like maybe the belt went on the PO or something like that.
As far as the fan clutch, I didn't feel any difference in resistance from a cold engine to a hot engine. That has to be the culprit here, otherwise I really not no clue. I went for a 1/2 hour trip on errands and noted the temps. I stopped at Auto Zone, and they could have a clutch tomorrow and it is around $125. I will shop around tonight on the usual sites we all use to see what I can see. So, are you all thinking the same thing? Is changing that out a quick job or is it pretty straight forward once you get the fan shroud off?
Start up temp was showing 49. Outside temp during the test was 63.
Hot idle waiting at bank atm drive thru:

Back road cruising after warmed up at around 50MPH

Highway cruising around 70MPH

 

See https://landroverforums.com/forum/di...acement-32370/ for a fan clutch that should be in stock at any auto parts store. Since D1 and D2 use same water pump it should fit.

However, I don't believe it is the fan clutch if you get these temps while driving. There is so much air going through radiator. To test theory, hold pizza box out the window at 50 mph... I had a fan start to wobble, I took it off and drove 30 miles, you don't need a fan as long as you don't stop for very long.

If clutch is toast, it usually, when warm, will spin by hand more than 1 turn (free wheeling). When stone cold, a clutch will normally engage at full power coupling, because fluid has settled to one side. This causes a fan "roar" for the first few minutes, until rotational force and warm up moves the fluid out through small grooves between the two halves of the fan pulley. A fan pulley is normally stiff at cold, and when warm, it may relax a little, but should not free wheel. When really hot it should be perhaps a little stiffer, but the Mark I palm reader should be kept away when spinning.

Change clutch is easy - once you get that nut broken loose on the back of the clutch, usually requires a whack of a hammer on a wrench (toward passenger side), while pulling up on fan belt or using an additional something to restruct pulley movement.

Might want to double check belt route again, before clutch purchase.

If you have IR thermometer, might measure the spot just beside coolant sensor. But your temp sensor on the gauge gave a read out of local air temp and engine temp, so if these were close at startup I would guess sensor is not way off.

You could also measure the inlet temp at the top radiator hose, if it reads 175 and gauge says 220, well, why?

I think your thermostat may be part, if not most of the problem. It seems like the "set point" is higher in all situations (idle and running), and this might be caused by junk in those tiny holes. If they are blocked, engine would get warmer before stat activates. The other culprit could be radiator, but you have a newish one. Clogged radiators usually show hot and cold spots across their surface, my indy shop says 10 degrees across the surface is a good sign.

 

First, if there are any cracks or pieces missing from your fan, replace it ASAP before it lets loose and flys thru your radiator and or hood.
As for the clutch, there are a number of chevy truck clutches, non a/c, that work well on our trucks for around $70.
I would try a salvage yard or get in touch with Will Tillery or Paul grant for a used fan and clutch.

 

Heres a page with belt route. I also swapped out my fan to a chevy fan and clutch from like a 2001 Tahoe, they use the same 6 inch diameter size reverse direction clutch. Under $20 at junk yard, had to trim blades to fit.

But while your fan needs attention from a balance point, and Mike speaks the truth about buying a new hood; unless it is bolted on backwards, it is not causing your almost overheat while driving at roadway speed.

 

Well Buzz, the temps did go up quickly when stopped, and decreased with higher speeds. The 15MPH highway difference was 10 degrees.
Mike, do you think it is worth it to just get new parts? I read the post about using the Chevy truck one, and sounded like the holes for the fan just needed to be modified a bit. I'm wondering if the fan itself could be swapped for a non-LR one. I'd rather get something new judging by the condition of the plastic on the current fan, and not have to deal with it again soon. Someone said they got a metal fan, so I assume it can be done.