New Disco owner/forum member and a question about thermostat

louielouie

Member
Jun 23, 2020
6
0
42.214014, -122.83402
I tried browsing thru the various threads about thermostats and didn't find quite what I was looking for:
Using OBDLink LX I had noticed that our Disco was running up to 216 degrees according to the ECU so I installed the 'soft spring' t-stat (supposedly 180 deg F) and the ECU reports 198 ~ 203 deg F now - better but still higher than I expected. Is that accurate?
-LouieLouie - 02/01 build date so I have the CDL w/o cable
 

louielouie

Member
Jun 23, 2020
6
0
42.214014, -122.83402
Silly me to believe the 180 degF/ 82 degC labeling - just wondering if anybody else had noticed this "discrepancy" is all. My jeep w/4.0l cast iron block & head seems to run comfortably at 195 degF (what the t-stat is labeled as) and everybody says not to run it colder.
 

Swedjen2

Well-known member
Sep 12, 2018
556
113
California
Well, welcome to the Dweb. Is this you're first LR? You know what you're getting into, right?
To answer you're question, yes, there is a discrepancy. On my stock '04 D2, I have a new 180 deg t-stat , new radiator, water pump, reservoir, etc., rebuilt 4.6 v-8 with 10K-ish miles. The rest of the vehicle has 165K, but is in very good shape.
Around town I run 202 max with the A/C on. Freeway temp runs 194-197. i don't know any V-8 Disco running at 180, maybe there are and i missed it.
The 180 T-stat is for the TDi engine, which was offered worldwide except in the U.S, of course.,

If you were running 216 before the new t-stat, you might need a new radiator.
How many miles on your rig, do you know the service history?
I have a Scangauge to monitor engine temp, RPM's, MPG mounted on top of the steering column. Autozone has them on a rack behind the counter.
Hang out around here and all your Disco questions will be answered to your hearts content, and then some.
 

discostew

Well-known member
Sep 14, 2010
6,403
493
Northern Illinois
Silly me to believe the 180 degF/ 82 degC labeling - just wondering if anybody else had noticed this "discrepancy" is all. My jeep w/4.0l cast iron block & head seems to run comfortably at 195 degF (what the t-stat is labeled as) and everybody says not to run it co

The rating is the temp the stat starts opening at, not the temp the engine will stay below. An electric cooling fan on most cars won't turn on till about 210.
 
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rovercanus

Well-known member
Apr 24, 2004
9,469
147
Thermostats don't set what your cooling system runs at.
A thermostat that is rated for 180* means that it will be open at 180*. it doesn't mean that is what your cooling system will run at.
Once again, 198 to 207 is fine.
 

K-rover

Well-known member
Jan 15, 2010
2,100
43
Raleigh, NC
The highest temps I see are at highway speeds with the AC on. It gets to 201 if Im doing 80mph. 65mph and it sits around 194-197. But if the AC is off, it will sit at 188 all day on the highway. Around town its in the 194-197 range with or without the AC.

I remember the rep from Atlantic British tell me that their warm weather t stat wasnt a true 180 unit. Not sure what he meant by that? but I ended up getting the TD5 unit from Rovers North several years ago.

Sounds like you're within range, although a bit on the warm side. Like others mentioned, other failing components could be the cause of the slightly warmer temps. Nothing to cause immediate concern, just keep an eye on it..
 

Howski

Well-known member
Oct 19, 2009
1,268
121
Alabama
As others have said, a bit on the high side but not bad. If you swapped in a t stat already that’s a good sign. Welcome to Discoweb
 

louielouie

Member
Jun 23, 2020
6
0
42.214014, -122.83402
Sorry about sounding snarkey - it *IS* my first experience with a LR/Discovery and since its the girlfriends she raises the stress level a bit because she second guesses everything that may have caused it. <sigh>
For the record it was purchased with 110k miles on it and has had the head gaskets replaced before at 60k but no mention of any cooling system work at all - the coolant was green and I'm replacing it.
I've flushed the dirty steering fluid with new CHF 11s (and now it's leaking from a hose I think), change the oil & filter, cleaned the MAF plus new A/F.

I *DO* appreciate the collective wisdom because even though it's a 'SD' trim level, it has the CDL (future lever to get) and we just put 265/70-16 Cooper AT3 4S tires on it - and its a VERY nice rig!

-LouieLouie
 

Blue

Well-known member
Mar 26, 2004
9,415
470
AZ
My mechanic (former Land Rover Master Tech and now has an independent shop) told me this morning that a D2 running in the 220s is really not all that hot. He's concerned when he see (or hears) about 230 or 240. I think 220 is way too hot. My D2 is in for an oil change and he's also installing a genuine parts 180-degree thermostat. We'll see if that helps. I think my engine is toast though and my Disco days will sadly be coming to an end soon.
 

Swedjen2

Well-known member
Sep 12, 2018
556
113
California
My mechanic (former Land Rover Master Tech and now has an independent shop) told me this morning that a D2 running in the 220s is really not all that hot. He's concerned when he see (or hears) about 230 or 240. I think 220 is way too hot. My D2 is in for an oil change and he's also installing a genuine parts 180-degree thermostat. We'll see if that helps. I think my engine is toast though and my Disco days will sadly be coming to an end soon.
Heat is the enemy of LR engines - the cooler the better, within reason. you are right, 220 is way too hot.
 
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Blue

Well-known member
Mar 26, 2004
9,415
470
AZ
Heat is the enemy of LR engines - the cooler the better, within reason. you are right, 220 is way too hot.

The 180-degree thermostat seems to be helping although I haven’t done any long highway runs yet. Maybe tomorrow.
 

JohnB

Well-known member
Oct 18, 2007
2,282
8
Oregon
Any modern engine runs around 212-220. Really do not think a D2 motor is considered modern and even though to satisfy US standards these old engines were tweaked to run that hot. They should not in my opinion. Mine just hit around 270k but I've tweaked the system to run at 175-180 for the last 130k. Have had all the usual problems but the block has never been apart other than a cam swap around 120k and head gaskets around 130k.
 

mlambert1987

Member
Aug 8, 2013
5
1
Boston,MA
Mine was hitting 215 at idle w/ac on. I replaced thermostat with a 180 and replaced radiator. Now she is around 190-195 on highway, 198-202 with ac on around town