Freelander 1 TD4 thermostat mod

I have a 2004 TD4 manual. I assume the thermostat has gone as even here in sunny Spain, the temperature gauge only gets to it's normal halfway mark when the engine is working hard.
I understand that replacing the original thermostat is an involved job and most people opt to fit a thermostat in a modified position.
Am I right in thinking there are 2 options?
One that is fitted inside the top hose and an inline one in an aluminium housing, spliced into the top hose.
Any thoughts as to which is the best option?
Cheers.

I've just noticed some cracks around the expansion tank neck and traces of coolant. If the cooling system is not pressurising, could that be why it's not getting up to temperature?

Jonny H said:

One that is fitted inside the top hose and an inline one in an aluminium housing, spliced into the top hose.
Any thoughts as to which is the best option?

Click to expand...

The thermostat in the top hose is cheapest. As for which is best? It's probably even between the two ways.

Jonny H said:

I've just noticed some cracks around the expansion tank neck and traces of coolant. If the cooling system is not pressurising, could that be why it's not getting up to temperature?

Click to expand...

No. But making the engine run hotter, will result in some coolant loss. Replace the reservoir at the same time as doing the thermostat mod.

going to do mine soon ..

found this .. should it be of use to the OP .. :
https://www.dmgrs.co.uk/products/rover-75-mg-zt-cdti-inline-thermostat-89-degrees

the related youtube vid:


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Cheers hd3.

FWIW ..
i ordered the thermostat from the above site ..
was delivered on time ..
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fairly easy job to do .. hardest part were seating the device inside the hose
a 32mm i.d / 38mm o.d. plastic pipe helped a lot for that
all in all it took about 1.25 litre of coolant to refill the system ..
1st fill just after finishing the instalment .. and running the engine for a few minutes
then a drive of about 15 mile
stopped and checked level again .. added a tad more coolant
didn't need to bleed the system ( plenty of hot air from cab heater )
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the thermostat has no i.d/spec markings on it ..
observing temps. whilst driving ( scangauge.II ) showed the stat. opens at 85c
and don't go below 83c on a long downhill run
before .. it were running at 75c .. and 66c on the downhill
and not really noticeable via the dash temp. needle reading
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looking forward to slightly better mpg. .. maybe
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