I have a 2004 DII with a new long block build from AB. New radiator, hoses, and thermostat 190F. The cooling system has been bled a few times.

Current temps seem to be too high for my liking with a new engine and new cooling components. Idle up to 215.6F, highway 210-212F (with the heat on in eco mode 208F), and around town around 206-208F. (temps from ultraguage)

The thermostat looks to be an aftermarket one, not LR OEM. It is the standard 190F thermostat, not the 180F one.

I plan to change to a OEM 180F thermostat and see what happens. Also, I found the the AC condensor fan is seized and needs to be replaced.

I was going to try the new thermostat next, replace ac fan and see what happens. If temps are still high I plan to replace the main viscous fan unit.
I have read all the great things about the inline thermostat but I'm reluctant to do it while the engine is still under warranty with AB.

Any suggestions on other things I should look at?

Thanks
Bill

 

Does the AB warranty say something about modifying the cooling system? Or is it just implied it all should be “factory”?

The factory 180 will certainly drop your temps. I think you’re running the normal factory 190 temps. I too have a truck with an AB long block that had a factory 190 thermostat when I got it and that’s exactly what I was running temp wise.

I did the condenser fan on previous DII and it helped with temps at idle slightly. Worth repairing. You can get just the motor for cheap, and just replace the motor instead of buying the fan assembly but that takes a little more time.

IMO the inline is the only way to go. It’s enormously simpler, will drop temps way more than the factory 180, and has numerous other advantages. It reduces a lot of the complexity of the factory system and makes it more like a D1 or anything powered by a small block Chevy.

 

Seconded, I don't run a D2 any more without switching to an inline thermostat. Lower as well as more consistent temps, cheaper and more available replacement parts.

 

@wildwilly69 Those are normal temps for 190 thermostat either go inline or get a black TD5 180

 

Thanks for the feedback. Based on reading the forum posts they seem high. Is operating at the temperatures I have ok or should I be worried? Reading all of the posts on high temps and engine damage I'm paranoid.

 

@wildwilly69 They are too high for an aluminum engine, in my opinion they were too high when the trucks were new. I run the inline and at 95F external temp, climbing a 13% grade at about 10-15 MPH or less for 25 minutes I hit 215 once for about 2 minutes averaged 200 to 208. Dropped to 164 coasting down the the other side.

The problem is head room at 200 to 215 you have 30 degrees F before over heat that is it. Any overheat event that lasts of more than a couple minutes 2 can warp a head or cause liner slip. For 100.00 you get another 20 degrees of head room it cannot hurt.

 

@WildWilly69 I have a handlul of new factory 180's I am never going to use, I am happy to give you one if you want it (you pay shipping). Just email me.

 

Check the fan assembly. Newspaper test. Or try it on the bench with a hair dryer or heat gun while spinning the blades by hand. Check if resistance increases when you heat up the bimetallic spring. Mine was shot, the new fan brought it down a few degrees. In my experience there is not single part that fixes high coolant temps. I started with 180F thermostat, then coolant flush, new fan and finally new radiator & hoses. Every step brought the temps down a bit.

 

Use the Land Rover 180 t-stat and be done with it. I just installed the 180 t-stat with a new radiator/water pump and am really happy with how much lower the coolant temperatures are both driving and sitting even when its 90+F outside.

 

This is the path I seem to be going down. IAs others have pointed out, you can probably count on having to redo the whole cooling system if you have overheating...but what happens to some (like me) is the first step is replacing the head gaskets, then when it still overheats the search is on for the next failed component. One should see if you can get the cooling system and temps under control and then maybe the heads won't warp and the HG's won't fail.
My other failure is that I have been trusting that just because it's a new part it's a good part. So far I've had a bad t-stat, brand new 180' jarvik heart that never opened, and a fan clutch that freewheeled when the cooling system warmed up at idle. If it's new and doesn't work it needs to be replaced again. I went inline t-stat, warrantied the fan clutch, and last evening I did coolant flush and the let the beast idle for 30 minutes and it never got hot enough to turn the electric fan on while the new fan clutch blew hot air around.
I replaced the radiator upon inspecting the original and finding it was literally falling apart. Glad I caught that!
It's a cooling system, and I have learned the hard way to diagnose and repair it as such.