Overheating
Rock Crawling
Joined: Jul 2018
Posts: 395
Likes: 80
From: Las Vegas
The local o’reilly’s surprisingly had a t-stat in stock so I picked it up. I re-assembled with the new parts and dropped it in boiling water. Did not really open much, which surprised me. But I went ahead and installed it. This time I also pre-filled the hose downstream of the t-stat and then for good measure injected more coolant mix into the throttle body coolant bleed valve. Between those two, there was maybe 2/3 of a gallon of air displaced which I’d think is kind of a big deal. I’ve been out on a couple drives and have burped and refilled it (very little added) once each and it’s sticking around 210F now. That’s progress! Can anyone let me know what’s a “normal” temp in 80 degree weather?
Overlanding
Joined: Sep 2025
Posts: 24
Likes: 8
Solved Update
Glad to have this one fixed. Received the OE 180 thermostat from Lucky8 yesterday and installed today. Also replaced the reservoir cap.
Bled with the original procedure and did an idle test. At idle in the garage on an 85 degree day the ECT never went above 201.
Waited a few hours to check coolant level. Coolant level was the same before the idle test.
Test drove with mixed city and highway driving for 90 minutes. Temps stayed below 201 and mostly were around 194-195 when driving.
So in review there were a few things wrong with the cooling system. Radiator definitely needed replacement. I replaced several hoses. Replaced the tconnector bleeder with an aluminum t-pipe.
Replaced failed fanclutch (after testing) with 2 piece replacement severe duty clutch and blade
Replaced original thermostat with O'Reilly Murray brand 180 thermostat. This thermostat appeared to be defective when testing in a pot of boiling water. Finally replaced with a 180 Degree OEM Stat from Lucky8.
Also replaced Coolant reservoir cap.
Glad to be able to drive the truck now! Now time to chase down all the miscellaneous issues.
Glad to have this one fixed. Received the OE 180 thermostat from Lucky8 yesterday and installed today. Also replaced the reservoir cap.
Bled with the original procedure and did an idle test. At idle in the garage on an 85 degree day the ECT never went above 201.
Waited a few hours to check coolant level. Coolant level was the same before the idle test.
Test drove with mixed city and highway driving for 90 minutes. Temps stayed below 201 and mostly were around 194-195 when driving.
So in review there were a few things wrong with the cooling system. Radiator definitely needed replacement. I replaced several hoses. Replaced the tconnector bleeder with an aluminum t-pipe.
Replaced failed fanclutch (after testing) with 2 piece replacement severe duty clutch and blade
Replaced original thermostat with O'Reilly Murray brand 180 thermostat. This thermostat appeared to be defective when testing in a pot of boiling water. Finally replaced with a 180 Degree OEM Stat from Lucky8.
Also replaced Coolant reservoir cap.
Glad to be able to drive the truck now! Now time to chase down all the miscellaneous issues.
Recovery Vehicle
Joined: Dec 2008
Posts: 1,037
Likes: 38
From: North Georgia
glad you figured it out. I'm about to do a complete cooling system rebuild on my LR3 after I figure out another major issue and you provided some good info.
Where did you get the aluminum t-pipe connector from?
Where did you get the aluminum t-pipe connector from?
Thread Starter
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Mudding
Joined: Sep 2020
Posts: 213
Likes: 40
From: S. Lake Tahoe, CA, USA
Glad you're past it. Relatively simple if you don't overthink it like I had.
Just a heads up, I had the water pump leak 6 months after I replaced my thermostat--not sure if it was also failing internally. Probably unrelated? It was not original and had been glued on with some sort of gasket maker. Replaced it with AC Delco Gold and haven't had any issues since. Re-reading this thread, I'm interested to know if it dropped the temp down to the range where yours is. I'll try to remember to pull it up next time I'm at temp.
All of this was at just under 130k for me.
Just a heads up, I had the water pump leak 6 months after I replaced my thermostat--not sure if it was also failing internally. Probably unrelated? It was not original and had been glued on with some sort of gasket maker. Replaced it with AC Delco Gold and haven't had any issues since. Re-reading this thread, I'm interested to know if it dropped the temp down to the range where yours is. I'll try to remember to pull it up next time I'm at temp.
All of this was at just under 130k for me.
Solved Update
Glad to have this one fixed. Received the OE 180 thermostat from Lucky8 yesterday and installed today. Also replaced the reservoir cap.
Bled with the original procedure and did an idle test. At idle in the garage on an 85 degree day the ECT never went above 201.
Waited a few hours to check coolant level. Coolant level was the same before the idle test.
Test drove with mixed city and highway driving for 90 minutes. Temps stayed below 201 and mostly were around 194-195 when driving.
So in review there were a few things wrong with the cooling system. Radiator definitely needed replacement. I replaced several hoses. Replaced the tconnector bleeder with an aluminum t-pipe.
Replaced failed fanclutch (after testing) with 2 piece replacement severe duty clutch and blade
Replaced original thermostat with O'Reilly Murray brand 180 thermostat. This thermostat appeared to be defective when testing in a pot of boiling water. Finally replaced with a 180 Degree OEM Stat from Lucky8.
Also replaced Coolant reservoir cap.
Glad to be able to drive the truck now! Now time to chase down all the miscellaneous issues.
Glad to have this one fixed. Received the OE 180 thermostat from Lucky8 yesterday and installed today. Also replaced the reservoir cap.
Bled with the original procedure and did an idle test. At idle in the garage on an 85 degree day the ECT never went above 201.
Waited a few hours to check coolant level. Coolant level was the same before the idle test.
Test drove with mixed city and highway driving for 90 minutes. Temps stayed below 201 and mostly were around 194-195 when driving.
So in review there were a few things wrong with the cooling system. Radiator definitely needed replacement. I replaced several hoses. Replaced the tconnector bleeder with an aluminum t-pipe.
Replaced failed fanclutch (after testing) with 2 piece replacement severe duty clutch and blade
Replaced original thermostat with O'Reilly Murray brand 180 thermostat. This thermostat appeared to be defective when testing in a pot of boiling water. Finally replaced with a 180 Degree OEM Stat from Lucky8.
Also replaced Coolant reservoir cap.
Glad to be able to drive the truck now! Now time to chase down all the miscellaneous issues.
Overlanding
Joined: Sep 2025
Posts: 24
Likes: 8
@cybercop The T pipe I found was available from Cars4x4.com, heres the link https://carrs4x4.com/collections/dis...inum-bleeder-t
@CantComplain Good catch! I also replaced the waterpump when I replaced the radiator. I think it was also an AC Delco unit.
Also went for a 2 hour drive today in even warmer weather with my brother along to monitor the temps and we stayed under 199 the whole ride on country roads with hills. So I feel confident I've solved the overheating issue.
My bad, just realized I replied to the wrong thread with my solution. I had another thread on the disco 2 forum!
@CantComplain Good catch! I also replaced the waterpump when I replaced the radiator. I think it was also an AC Delco unit.
Also went for a 2 hour drive today in even warmer weather with my brother along to monitor the temps and we stayed under 199 the whole ride on country roads with hills. So I feel confident I've solved the overheating issue.
My bad, just realized I replied to the wrong thread with my solution. I had another thread on the disco 2 forum!
Last edited by Niohdachi; Oct 3, 2025 at 11:20 PM.
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