Having the heater blasting may help with reducing the coolant temperature, but it doesn't do anything to help bleed the system. The heater matrix is always at full flow regardless of the cabin temperature setting.

 

Thanks, yeah I had thought this before but just blindly following the internet advice to run the heat hot.

This is why I thought I might try bypassing the heater core entirely to see if it was responsible for a flow restriction.

 

Diagnosis of overheating in a V8 Petrol Land Rover

 

PLEASE understand the hot coolant temperature on a running vehicle is NOT related to the thermostat rated 'number'.
The thermostat ONLY changes coolant flow path at its rated temperature. Running uphill, or in 90F ambient, or under a lead foot, or pulling a trailer, or lean mixture, or a bunch of other reasons will raise the coolant temperature, no matter what thermostat you have in the circuit. The thermostat will not hold the temperature from rising.
When the thermostat is open, it will not open any more. Flow towards radiator is fixed. If vehicle is exerting more effort, it will run hotter beyond the thermostat 180F or whatever 'number' may have.

A '180F' thermostat does not imply the running temperature will be that number. To find out the capabilities of all the other cooling components, remove the thermostat AND block the bypass path. Then run it in high ambient temperature, towing or climbing to find how well the cooling system performs.

A '180F' thermostat implies it will divert the coolant flow towards the bypass path if the temperature falls under 180F to prevent running cooler !

 

Mechanical thermostats DO open more the hotter they get after their opening temperature until fully open. The wax in the thermostat keeps expanding. Additionally, his running an inline thermostat, the bypass is GONE.

 

I agree with all of this. My concern isn't with the thermostat. I am unhappy with the thermostat open temps so I am trying to address solutions for that such as more airflow or bigger radiator. The only reason I mentioned thermostat was if it is restricting flow when fully open more than it should be, the cooling system would be not performing well.

I am not chasing 180f at all times, I just would like to not get to 220+ in the heat over mountain passes.

 

Whoever wants to run a cooler engine, needs to cool more or heat less. A thermostat does not do any of that.
If three exact vehicles have one a 160F thermostat, another a 180F thermostat and the other a 200F thermostat; put to race in the same circuit track side by side by side, one will reach stable temperature in ~5 minutes, another in ~4 minutes, and the other in ~3 minutes.
All vehicles will run at the same exact stable temperature after that because all thermostats are equally fully open and thermostats do exactly nothing after opened, NOTHING*.
If ambient is 90F, speed 80mph, pulling 1 ton, perhaps the running temperature will be 215F. On all 3 vehicles. Want to run cooler ? Install a bigger volume radiator, or expose it to more wind, or reduce the water pump pulley diametre or...

*Unless in arctic ambient falls to under thermostat rating.

 

my question with the inline mod. Are you sure it allows enough flow? If it is restricting flow compared to stock, it will allow temps to rise. I would try removing it completely and trying the hill again.

 

Again, I agree with all of this and have never said anything to the contrary.

 

Yeah I was suspecting this as well. Its a bit tricky to test since it has to be like 90f+ outside so I have to go on a pretty far drive in the middle of the day. I will give it a shot though.

Its a bit of a shame since it is running so great otherwise. Just drove an hour on the freeway and city streets and the highest I saw was 184.

Thanks for the idea. I will try it out and report back here.