Finally got myself the Ultra Gauge so I could keep an eye on a few things, and have questions now about what the normal operating temperature should be on the truck. With my normal around town and some highway driving the past few days, the temperature tends to be in the 220's the entire time. I see according to the RAVE that the cooling fan comes on at 212, and off at 202. So, by this, that means it would be going all the time. It says the cooling fan will stay on when the ignition is off if the air intake temp is 140 or more and the coolant temp is 230 or more.
So, for those in the know, what is the normal operating temp for the coolant? Figure current temps during the day are 45 or 50 out.
What is the maximum safe operating temperature?
I see the factory idiot light comes on at 250. Even stuck in traffic on a very hot day I never had the light come on (the transmission temp one came on for about 30 seconds in traffic one day though and that was all). Should I set an alarm for maybe 245? What is the highest temp before things get bad?
Thanks! Just trying to get all my ducks in a row before some longer ski trips this winter. I know coolant temps are more to worry about for the summer, but I would still like to see what is going on during the winter and the factory gauge is of no use.

 

Mine sits around 95 to 105 c. thats around 200 f. 220 sounds a lil hot for me, but my calculations may be off....

 

To me it seems a touch high as well, but just not sure. Never overheated, light never came on, and got stuck in some nasty traffic in 100 degree days this summer. The entire system is pretty much new in the last 2 years. PO did not radiator, water pumps, thermostat and some hoses. I had a few small leaks when I got it, and did the lower hose and another one. I also did a full flush when I did those, even though everything was pretty new including the coolant. I have a small leak now (level never drops but see a bit in the morning on the driveway sometimes) that I have not been able to track down yet. I tightened the hose (the one I replaced) that goes into the water pump as that seemed a bit loose. I have to get back under there and see though.

 

my 2000 usually sits at 99C / 210F thats taking the temp from my ecm using a hawkeye scanner

 

I have not been able to verify where the Ultra Gauge actually takes the temp from yet.

 

Stop frying that Disco!

Normal temp should be in 190's, when truck is running down the road with no trailer on level ground. Thermostat for D2 (they only make one heat range, I think) is rated for closed at 179F, fully open at 204F.

Would check the following in no particular order:

Coolant level - one person found they were two gallons low!

Radiator - clogged with mud or leaves (between condenser and radiator)

Radiator - chemical flush coolant out (Dexcool or old coolant, or old coolant plus stop leek previous owner put in) - if you always used well water it will be high in calcium build up. Distilled is best.

Thermostat - could be marginal - there are four holes that allow hot water to reach the stat and activate it. If those holes are plugged with trash or stop leekz, it will shift temp range up. These holes can plug because stat is mounted vertical and trash settles to the bottom.

See this pix from a post about temps being too high https://landroverforums.com/forum/at...mostat-005-jpg - those holes need to be clear.

Aux cooling should only come on/off with AC at speeds 50 mph or less, 82 F and above; off at speed of 62.5 and/or temp of 77 F or less outside. If engine gets to 212, fan comes on. But that is overheating, except in heavy traffic in the summer.

Normal level is NOT 220. And not 212.

Fan belt - check route and tightness (not slipping)

Water pump - old ones don't move as much coolant, eventually leak and wobble the pulley, about $50 and up part, 1 hour.

Fan blades - air should move toward engine, not be blown out the front grille. Sometimes fans have been mounted reversed, re-wired (condenser fan), etc.

IMHO you alarm point should be more like 219, so you have chance to take action.

Tranny and transfer case share the warning light for them, transfer case will light it at 293F. If you are not getting the cooling you need on the engine from fans or mud plugged fins that could impact tranny temp. Of course check fluid level in each.

Fan clutch (main) should be checked, when truck warm it should not spin freely by hand. 1/2 to 1 revolution only, should feel like there is peanut butter inside it. However, fan clutch does not make much of a change when runing at 50 mph, only at low speed or idle.

I bet your factory temp gauge is "normal"... glad you caught this.

 

Here's where the ECM gets the coolant temp from to display with scanners connected to the monitor port

 

Both my Disco's have new radiators and Thermos. The odd thing is the 04' with a new block runs at 200 while my 03' runs at 180-190. I would think the 04' with everything being new would run cooler, go figure..

 

If you are not running in the high 190's, this time of year, you have some cooling system issues, which could be the radiator, t/stat, coolant mix. electronic fan or the viscus clutch.

Snafu, you need to work on yours before you get into trouble.

 

my 03 disco with 90k and the HG's done at 55k sits around 204 when travelling at 60mph down the freeway. The highest I have seen it is in traffic in DC when it got to 215. At no time has the idiot gauge moved from level 3 oclock position. The only probem I have found with my ultra gague em is that on a cold start it shows 46?