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Bought 2000 Disco II last month, 103K miles. No major mechanical issues I could find wrong (which in and of itself is highly suspect... I know).
Based upon advice here bought Ultra Gauge. Couple weeks of driving getting my UG baseline, generally 197-203 normal driving. Idling, Highway, etc. Probably 800 miles of driving.
This morning I was seeing 200, 204, 208, 210, bouncing between 198 and 210 as I was putzing around town. Then Ultra Gauge alarm went off. I set it very conservatively to make me pay attention. Truck never got above 212 running bc of this gauge and me paying attention as a result. Heat on. Revved it up (by revving a bit I could get temps back down to 199). Home was 1/2 mile away.
At home, I checked both main fan and the condenser fan and seemed to be working as intended. So I put in Genuine 180 Rover T-Stat (grey one I purchased here in Portland). The "bad" one in the truck was beige-ish and the plastic was actually decaying where it was exposed to air... what a piece of crap... no idea how old or what brand.
Got it back together... temps now 186-188 stable for an hour of driving. BOOM.
Super thankful that the board here convinced me to get an Ultra Gauge (or another similar device) and then this 180 degree genuine stat. Would have had no idea and could have been looking at head gaskets or worse.
My Ultragauge saved me once like this too. The T fitting in the coolant system failed on me (didn't know that). I saw the temps spiking on the Ultragauge long before I heard or smelled an issue, let alone the stock temp gauge.
Deviation from baseline. If I had not known, it could have continued and may have days or weeks from now been 230-240-overheated when the stat gave up totally. The UG alerted me to a change in baseline temp readings (“normal for my Disco”) and thus indicated a potential early failure warning. 212 in and of itself was not the issue.
Up to 220 are normal with a stock. 212 is not an indication that the thermostat will fail. There are multiple factors which impact the coolant temp like condition of fan, radiator and coolant.
The have friends that are totally puzzled to see me open up my iPad mini and monitor my engine sensors and temps with the Ultragauge Blue app on such an old truck.
I tell them “Yeah. Land Rover was way ahead of their time.” Lol
lucky you had a secondary temp indicator! I also have found the dash temp gauge is not too reliable. Mine has pegged on occasion and there was no pressure in the tank, and the coolant was barely lukewarm.
Always good to check belts, hoses, etc. I usually check things over at each gas fill which for me is about 2-3 times a week. Glad you are not out looking for a replacement motor!!
Up to 220 are normal with a stock. 212 is not an indication that the thermostat will fail. There are multiple factors which impact the coolant temp like condition of fan, radiator and coolant.
This is wrong. Factory design thermostats are the single most common failure point on a D2 and the gradual temp climb is initial indication the bypass valve is not functioning. Sorry to be blunt, but after owning and driving 22 D2s over 10 years I would never run a factory design thermostat. I have two brand new never used that I am willing to give to anyone willing to pay shipping. They were left over from my parts stock when I finally decided I could no longer depend on even new D2 factory design thermostats.
OP, good call on the Ultragauge. Now you should seriously consider going inline.
Having an Ultragauge saved me today
