Cooling System

Please can someone explain
We have an 05 freelander petrol can someone explain the cooling system because i am baffled
This is the beginning it blew the head gasket not a huge overheat
still had the head checked and pressure tested full head gasket kit and bolts , new water pump, new timing belt.
Replaced all hoses,inc thermo unit, coolant bootle and cap Radiator,and finally red coolant
Bleed the thing to death
Car Runs Normal temp with or without air/ con idles indefinatly at just under normal thickness of the needle under the middle
here are my questions
1 still uses a small amount of water just that top up in the header tank
2 the hoses just seem under so much pressure you can see and feel it
if you touch bottom hose its cold as if the car is permanently on bypass have checked with temp gauge the stat will open at 82 ish most of the time engine is just under stat temp
i just dont trust or understand this car the stat situation
Could someone just confirm this is right by touching there bottom hose
please

I'm assuming it's a 1.8 K series. What makes you think the bottom hose should be anything other than cold?
The purpose of radiator is to cool the coolant. Passing the coolant through a radiator makes it cold, the radiator wouldn't be much good if it didn't.
It does sound like it could still have some air in the system, so you need to check the small return pipe is actually flowing coolant back to the tank.

Didn't know they made any other engine size in petrol in 05 , thank you also for explaining how a radiator works
In reply to the only piece of useful information, yes there is flow on the small hose from the head.
Also let me enlighten you Thermal shock !!
a mass of cold water meeting extremely hot water.
what i expected was the bottom hose to be warm rather than stone cold, which would have indicated to me that the water was mixing,
If someone asks me for help I say nothing if i cant help, what i don,t do is ridicule them ,

broncoupe said:

Didn't know they made any other engine size in petrol in 05 , thank you also for explaining how a radiator works
In reply to the only piece of useful information, yes there is flow on the small hose from the head.
Also let me enlighten you Thermal shock !!
a mass of cold water meeting extremely hot water.
what i expected was the bottom hose to be warm rather than stone cold, which would have indicated to me that the water was mixing,
If someone asks me for help I say nothing if i cant help, what i don,t do is ridicule them ,

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LR made 2 petrol engine Freelander's in an 05. One is the 1.8L K series, the other is the 2.5L KV6. No ridicule intended, btw. The question is asked many times a month and twice today.

The rad fitted to the 1.8 is the same as that fitted to the 2.5 V6. So there's much much more cooling capacity in the rad than the 1.8 needs. So it stands to reason that the coolant returning to the engine is cold. On a V6 FL1, the bottom hose is generally about 10° C above ambient. Now the V6 dumps twice as much heat into the cooling system than the 1.8. So by simple physics, the coolant returning to the 1.8 will be cooler than 10°C above ambient.

You mentioned thermal shock. What do you think the primary cause of HGF is on the 1.8? It's thermal shock, or multiples of to be exact. It goes like this. From cold, the engine warms up to 86°C or so until the thermostat opens in response to the coolant circulating in the bypass circuit. The thermostat is then cooled rapidly by the deluge of cold coolant from the bottom hose, so it closes again. The coolant again circulating through the bypass circuit up to 86 odd ° C, at which point it opens again. Another gulp of cold water cools down the stat again and it closes. This cycle is continued over and over, especially when the weather is cold.

This is the exact reason why the HG fails, because of the continual heating and cooling. The block and head are always expanding and contracting, which over time causes delamination of the HG elastomer seal.

LR resolved some of this issue with the fitment of the bypass thermostat, but thermocycling remains a problem as the rad is still massively over capacity for the 1.8 engine.

I hope that explains it better without patronising.

Now that,s what I was after !!
totally get it completely imformative and confirms what i have achieved .
Which is and i confirmed this is with a laser temp gauge a much more uniform temperature throughout the hoses and rad.
I also took the car for a 30 mile test drive to be fair it drove fautlessley
have some 70mph roads round here, and on a quick stop the bottom hose was warm
so happy underload things are working as per your description
Thanks again

broncoupe said:

Thanks again

Click to expand...

Should think so, Mr Clever-Cocky-Pants.

broncoupe said:

If someone asks me for help I say nothing if i cant help, what i don,t do is ridicule them ,

Click to expand...

Been a member for 2 1/2 years, been helped numerous times and never helped anyone else. So maybe you know sweet FA.

Dick head.