2003 Disco 2. 112,000 miles. Petrol. Texas. Ambient temp 85f. Test drive after installing a new water pump, pulley, viscous fan, 180 degree thermostat (Atlantic British) and a temperature sensor (the one under/behind the AC compressor on the top of the engine). New belt and pulleys. Fresh fill of 50/50 DexCool. Was hoping to see temps 185-205. The truck is running fantastic. Is this an issue, or is this measurement being taken from where the engine is hottest?

 

if that temp reading is correct, then something isn't right. possibly the new thermostat isn't opening or the radiator is clogged.

 

Nope that is running hot,you should be at least 20 deg colder. Could be the thermostat is bad, air in the system or rad. But you have 16 deg f to overheat at the temp.

The thermostat problem is there were lots that were just crap in the after market. Try a complete rad flush forward and back.

For comparison the same heat here in BC at 70 MPH on the flats I ran 181 -183 inline mod and hi flow thermostat with a more aggressive fan clutch,up hill on 12% grade I hit 206-208 at about 60mph.

You need to do some work.

 

I'll backflush the radiator and see what that does. Probably test the new thermostat at that point as well.

Adding to the confusion is the dashboard coolant temperature sensor which shows nominal after warm up.

 

The coolant temp gauge in the dashboard is somehow tampered by factory. It goes to center already when engine is just lukewarm and doesn't move up before it significantly overheats. Don't trust it, an ODB-II reader or a aftermarket gauge shows you a more accurate temperature.

Make sure you bled your system multiple times.

 

That Disco II coolant thermometer is not. It is an adorn for the dash, tells nothing. Its red light is not connected to the chime. Another engineering stupidity.

 

Read the inline thermostat thread at the top of the forums, make your own decision. Look at this https://extinctmotorsports.com/the-e...ry-thermostat/ Be sure to report back your findings

 

There are a bunch of places that can have hairline leaks that will cause hotter than normal running...

1. Coolant reservoir
2. Hoses (replace them if they are 10+ years old)
3. The skinny hard plastic cooling hoses (replace them with 5/16 transmission cooler hose)
4. The throttle body heater and its hoses (bypass that crap in TX)
5. Factory plastic thermostat (replace with the inline thermostat mod!)
https://inlinethermostats.com/land-r...38-inline-kit/

 

Bleed it a bunch of times - that's much too hot. In stock configuration, these have very difficult to bleed systems. Check which thermostat you got - you may have gotten the factory 190-degree thermostat, as I did once a few years ago when ordering a mis-listed part. You want a 180-degree unit, which are usually in a black casing.

Also, I wouldn't recommend DexCool. It's a pretty awful coolant and likes to gel up and clog things. The generic green stuff is far better.

As others have stated, the temp gauge on the dash has 3 positions - cold, anywhere between 160 and like 240, and then it'll swing into the hot in a single swoop, at which point it's likely too late and you've already cracked the block, dropped a sleeve, or blown the headgasket.

I find it helps a lot to bleed it at around 2k rpm - hold it there, then crack the bleed screw - the extra speed on the water pump will help push out some air.

 

Bled the system again. Was able to add about 10 ounces before coolant was coming out of the bleed screw. Now a peak temp of 209f at idle. Confirmed I did install a 180f "Warm Weather" thermostat from AB. Will bleed again.