Just wanted to provide my numbers here!

Replaced the radiator with a new one, put in a Motorad 439-180 thermostat, and flushed/refilled. As you'll see in my other post, as of now I am not sure of what my mix ratio is:

https://landroverforums.com/forum/di...l-issue-53993/

In any case, here is the before and after from my UltraGauge. These are all operating ranges with lowest to highest observed, and my truck is a 2003 Disco II with 70K on it. Waterpump is new also.

Before:

Idling: 215.6 to 221
City speeds: 212 to 217.4
Highway speeds: 210 to 215.6

After:

Idling: 199.4 to 206.6
City speeds: 199.4 to 203
Highway speeds: 195.8 to 201.4

I'd call that a success.

 

If all else is OK, then your radiator is partially plugged up, replace it and you will drop even lower.

 

Hi Mike,

Radiator is brand new, water pump has only 3K miles on it, and both fans work perfect, new expansion tank cap. Motorad 439-180 thermostat. So...everything in the cooling system is pretty much new. The only thing that is probably not right is the coolant mix ratio.

Thanks!

 

X2 on the clogs if radiato original. What will happen now is

(1) - if cooler time of year you will think everything is "peachy"; while the clog continues to grow by chemical reactions that take place 24/7, just at slower speeds while at cooler temps.

(2) - next summer your rad will be even more clogged, and heat problems will slide back up.

(3) - Pix of clogs. In a D2 rad, the spaces are so tight and the plastic so brittle on the side tanks that cleaning out by rod out is not practical. So a D2 radiator is a disposable item, like an air filter. On a D1 rad, which is copper and brass, they can unsolder a side tank, rod out the calcium buildup, and solder it back up, if caught in time.

(4) - monitoring with scanner or ultra gauge is a good thing. Maybe even a written log from time to time.

(5) - if done before clogs get much of a buildup various flush methods can prolong the swap of a radiator in any vehicle. But time, temperature, and corrosion eventually win. A radiator can be had for less than the price of parts for a head gasket on a D2.

if in question about % - a specific gravity tester (floating *****) will give you an idea. Or just flush with distilled water poured in from top and a hose off on the bottom, run engine a little to circulate coolant mix. Then re-fill and bleed. For a real test take some of the existing coolant and put in your freezer. Should stay liquid.

 

Missed the radiator replacement.
That being the case, you are still 5 or 6 degrees above what others have reported.
I will be replacing my Radiator and t/stat this month and will post what changes I get.

 

Thanks for the reply - I will repost with updated numbers once I adjust my coolant mix and make sure I have all air purged from the system.

 

You might want to flush the system with distilled water before replacing the coolant.