Freelander V6 Overheating

My car FR1 V6 also was overheating after about 15 minutes on. The problem was in a metal connection "T" between the expansion tank and radiator that was blocked by rust.

Thanks to Hippo and Nodge for the info - actually makes a lot of sense to me.
Given those details
- the newest cap is the clicky one, which has a ratchet that was added to prevent over tightening because that causes the seal to fail (as I warned about in previous post)
- my local dealer still has the old caps

However, my previous clicky cap didn't tighten enough before it clicked.
Maybe there is a way to increase the spring pressure so they need more torque before they click?

I'll stick to my non-clicky one until I break it!

I prefer the original header tank and old non clutched cap. The old tank never cracked around the neck like the modern offering.

As anyone ever tried a different header tank from another car ? if so which one, could a mini one be adapted, I had to change my header tank recently due to cracking around the top filler part, quite an easy job and can be done with out bleeding the system, as long as you clamp the large hose first

The car has been working ok for the past two weeks without overheating. I changed the thermostat and bled the system thoroughly. Took the car to work this morning and out comes the steam from the expansion tank again. Exactly the same symptoms as before, expansion tank full of coolant, and now the expansion cap isnt holding any pressure again. The coolant hadnt dropped to right to the bottom of the expansion tank again.

Im really out of ideas now, no idea what it could be next

Did the fans come on at all, if so when? Just wondering if there may be an issue with the signal from the ECU or the sensor? Do you have anyway of checking the engine temp for when the fans come on, I use a TorquePro app on the phone, gives quite an accurate reading.

(Arctic2 I believe the Bini H/B compensator is transferable to the 75/ZT )

Same problem here. My FR overheated and I´ve changed the timming belt, flush the coolant, tested the thermostat in hot water and water pump. Found too a "T" connection obstructed inside the radiator. After mounting all, the car works very well, starting the fans in 96ºC and engine temp stays in ~100ºC.

After 2 weeks, traveling on the highway the problem occurs again with same symptons. The coolant fluid is not going in the radiator, but going to heater, IRD, gearbox and oil rad. It appears that the thermostat housing is stuck closed, makes coolant circulating only in the engine block.

I removed all the coolant fluid and pressurize with an air the expansion tank and has no leaks inside the block and hoses.

For tests now I´ll remove the thermostat housing and make a method to fix the valve to stay always open, to the coolant circulate always to radiator.

I have spoken to an MG Rover specialist who works with these engines on a daily basis. He thinks it is either one of two things. The head gasket or the water pump. Im going to get a chemical sniff test done to confirm if exhaust gases are mixing or not. At least I can rule the head gasket out then...

Any steam from the exhaust? Any mayo in the oil? Mine had steam in the exhaust and I could smell exhaust fumes in the coolant bottle, this was a poorly fitted exhaust manifold gasket, easy fix. I know V6s have a reputation on here for HGF, but elsewhere they have quite a good name, especially when compared to the 1.8s. I would be a tad cautious.

Found a problem!!
There is a thermostat valve in return from heater and gearbox. The T connection is broken and the spring and valve are loose.

Correct Name: Heater diverter valve (From 2003 Model Year)

This part sold only in complete kit with heater hoses. (Part Number: PEH000223/PEH000224/PEH000250)

I´ve fixed the valve using a nail and cutted one turn from spring. Inserting the part on hot water, the valve opens at ~80/90ºC and closes when cold.

Let´s install again and try.

Fingers crossed it's the culprit and it solves the problem.

I hope that fixes your problem. I feel like giving up on mine, and just sell it as spares or repair.

Before you give up on it, remember K-Seal.
It's the only product of its type that I know definitely works.
Also fixes heater matrixes, black death, piles etc.

blocks radiators, fine water passages in heads..........

If you're local to me, I'll take a look. If you decide to sell, I might be interested but only if it doesn't have K Seal in the coolant!!

I have run a chemical test to look for exhaust gasses in the coolant and none are present. Looks like the head gasket is not the culprit! Going to fit a brand new genuine expansion tank and cap today.

New bottle and cap are now fitted, done over 100 miles in it since and have had no issues! I dont think the old bottle was a genuine part, the cap didnt tighten down anywhere near as tight as it does with this one. The threads on the old bottle also allow you to screw the cap down so it doesnt sit flat, allowing the water to boil at a lower temp. Im going to be very pleased if this has cured it, time will tell i suppose!

Another result - hopefully.

Well, I've finished to mount all parts now.
I purchased a new thermostat valve housing to prevent opening the intake manifold again and changed the gaskets.

The engine heated up and placed 100°C at idle and when accelerating is oscillating between 94 and 100°C. When turn the air conditioning on was at 97ºC.

At a moment on start, it reached 110°C at idle but accelerating fell to 100°C again.
Now time will tell if the problem is solved because the last time the results were these but overheated. This engine is mysterious.

My feeling is the coolant prefer pass through the bypass hose (heater air, IRD, oil and transmission rad) than the radiator. It is possible to understand because the bypass hose is hotter than the output of the radiator. In theory if install a nipple in bypass hose to reduce the flow, the coolant prefer pass in the radiator.