How many times did you flush the coolant system? I normally do 4-5 flushes.
What did you flush the coolant system with? Straight water?

If it is an old cap, go and replace it. They are about $15.

 

 

I agree get a new cap

I also think you should work on isolating the issue

1. ensure T-stat is working
2. ensure fan clutch is working
3. ensure heater core is not clogged

Check the last couple pages of this thread for what person did

https://landroverforums.com/forum/bu...e4/#post646250

 

Lower temps when driving highway speeds typically suggests a bad fan clutch. Lower radiator shroud is on? Upper radiator shroud is on? Fan blades intact, not chewed up?

External radiator fins aren't clogged (I once had a newspaper stuck across a radiator from road debris!)?

Getting a steady stream of coolant out of your bleed screw probably means that your water pump is fine (it's moving that stream of water).


Next you can test your coolant to insure that no exhaust smoke is entering.


I use a product called "Cool Down" in a bottle that dropped my coolant temps about 6 degrees F. Maybe it will help you. Heck, use 2.


Also, insure that your thermostat is fully opening. 50-50 coolant to water, not 100% coolant, etc.


See if turning your cockpit heat to High will lower your coolant temps, too.

 

Also, check that you have a full 6.9 quarts of new oil because a low oil level and old oil will cause your motor to run a little hotter.

 

 

When you say the fan clutch is operating fine, are you outside the D2, revving it up, and watching the fan clutch to see if it engages/disengages? It's always going to be spinning, the key is if it's actually engaging/disengaging. You can grab a Dorman 620-112 Fan Blade and HD/Severe Fan Clutch for less than 75.00 normally. 03-04 one piece unit is nearly 300-350.00 for a new one and it's a total waste of time to replace it with the OEM unit when you can grab a two piece unit for under 100.00.

You've either got a bubble in the system, or a part of it isn't functioning properly. Radiator could be clogged as well (especially if it's the OEM unit) and I don't mean internally. It could be clogged up with mud, dirt, bugs, leaves causing poor air flow thru the radiator = isn't going to be able to cool down the coolant.