I'm a dedicated lurker in these parts, but I couldn't quite find what I was looking for from the search engine.
My wife had a close call with overheating the other day. I luckily had just installed an UltraGauge three days earlier and I'm grateful I did!

Here are the details:
2000 Disco II 99.5K miles. DexCool was in it up until today.
The TB heater had been leaking prior to this so I had one on hand. I put that in today with a new 180 thermostat (Motorad - yeah, I know...didn't know better before I bought it), flushed cooling system (with just the garden hose) and bled it per Rave instructions found here. I figured (hoped) that may have solved the issue.

After the install, I ran the truck up to operating temp sitting in the driveway. No visible leaks and the temperature held around 194 for a while so I drove it around the block...temps started rising fast. I got out, took the radiator shroud off and felt around the radiator....the upper hose and a very small area by the inlet were hot, but the rest of the radiator, along with the lower hose were cold - and uniformly cold at that.

Anyway, I'm pretty sure the radiator's clogged-although I guess there could be air in the system. I'm mostly ignorant when it comes to diagnostics so basically, I'm looking for a little hand holding before I spend the money.

Thanks in advance. I really appreciate everything I've learned from this site - you guys have saved me thousands of dollars in my Land Rover journey.


WaldoWilburforce

 

You could boil some water and make sure the stat is opening

 

You could boil the stat. What happens when it opens around ~180f? You're going to start thinking about that radiator again, aren't Ya?!

100k. I'd swap it out.

I purchased my radiator from BP Utah. It's great insurance. While you're at it pick up a Genuine 180 stat from Lucky8 or RN and swap it out. Fill up with some old school Glycol Green and be on your way. Feeling saucy?!!
Put a water pump with a brass impellar in your cart to complete the overhaul of your cooling system.

 

Fyi, radiator from BPUtah which they are selling for $280, not including shipping..

I encountered the same issue as the OP last year and went ahead to change the radiator. I also ordered mine from BPUtah.

Turns out it is a Nissens which was dropped shipped directly from Nissens to my door. So, total cost came out to be roughly a little over $300.

To OP:
You can buy from other sources which is much less and some may also include shipping. Just make sure you specify the Nissens radiator either with the SAI or non-SAI fitting.

 

You been lurking for a while AND using dexcool?

My truck came without dexcool. And hasn't over heated, but that's the only evidence "I" have.

As I understand it, if yr vehicle has used dexcool for a number of years, you have to suspect a stack of clogged up issues. Search threads. You might need a few years and a chair.

Easy stuff to do, for peace of mind, lack of sensationalism is just take off the stat, and rad hoses. Have a look at them. Do they have "any crud" in them? If they do, the smaller holes and gaps in your rad have far more.

Wait, reading your post again. You "put in a new TB heater, and 180 t stat" then flushed with water, then it over heated?

You are about to start a flame war, but how did y bleed the system? Is there a chance there is a massive airlock after your work, and that caused a spike in temps on the UG?

I might have drunk 6 JD and Cokes, but i still think my logic is sound. Where are my keys.......?







Joke.

 

All good advice^^.
I've had the truck for a year, P.O. was running dexcool and I switched it to G-05 with this work. The cooling system *looked* clean, but I'll re-step through the work and 2x check it all today. I boiled the original t-stat last night and it did open properly - will check the new one too.
At least any external leaks at the TB are fixed now, so i can address any other issues as need be. This is a Non-SAI truck, so if we go the radiator route, at least that one part of the equation is solved.

Thanks for the help. I'll be back with what I find out.

 

So...Both thermostats open when boiled. System bled and re-bled per RAVE; everything on the system gets hot when I idle the truck and I get hot air from vents w/ no waterfall...radiator and lower hose still cold with hot engine so i figure either I've got a massive air block, clogged radiator, or a weak water pump. When I rev the truck at idle, the temps drop slightly and the warm spot in the radiator grows marginally. WP looks to have been replaced by P.O. Gonna change the radiator at this point; as stated above, at 100k and 15 years is cheap insurance.

 

both T-stats will open when U boil them, water boils at 212F (100c) at sea level, if U R at high elevation it can boil at 205F (96c), it should start opening way B4 water boils 180F (82c), Try and see if one open's sooner than other as u heat up water, before boiling. Now If truck had DEX-COOL in it for 15 years and was leaking every now and then the air pockets inside engine (from lack of coolant) could have developed crystals in some areas and contribute to over-heating when needs more water circulation as you start driving, ((I am not rulling out bad radiator)). Other thing is that you R still using DEX-COOL's brother G5 which is pretty much same thing but the Hybrid version . almost all coolants in market today are OAT (Organic Acid Tecknology) or Hybrid version of it ( toyota pink ,VW G12,GM DEX-COOL, FORD & mercedes G05,BMW blue, HONDA dark green , etc,,,) very few are still what we call north American Green coolant , like store brands that are inexpensive , so drain the G5 and use one of those , or you will be still using the same thing that ruined your cooling system. OAT coolants are excellent but for engines that dont leak at all with newer materials used for seals and gaskets. Here is couple of link's for different coolants content's







( Universal Coolants ) ( Top it Up with Green? Or Orange? Which Antifreeze? - Column - Car Reviews - Car and Driver )