Freelander 1.8 K Temperature Issue - rises when idle and back to middle when driving

Hi All,
I have been struggling for the past year to get my freelander back on the road. Had 3 HGF before replacing to another used engine who did only 45k (seems in good state with no work done on it). Changed all the hoses, coolant pipes, water pump, complete inlet manifold assembly, inlet manifold green seal, installed new modified thermostat and still getting an issue with the temperature gauge.
When I am stuck in traffic, the temperature rises to almost 3/4 before going back to the middle, doesn't happen while driving though. Doesn't seem to be any water leak or loss neither.
The only thing I have NOT changed so far is the coolant brown sensor and a new radiator which is quite expensive.
I am in Mauritius so any parts need to be ordered from the UK, with about 20 days for delivery. Anyone can please advise which part might be faulty and how to detect?

That's quite normal really, can you hear the cooling fan kick in when the gauge gets to 3/4 point??

Yeah, it does and then the temperature gauge goes down. I have driven this freelander for the past 4 yrs, and never did that to me before, temperature gauge would stick to the middle all the time without moving, Only started to do this after the first HGF.
I am just wondering whether this is what caused the HGF the first and remaining time, and do not want to live another episode of this.

Was the thermostat changed at the time of the hg job??

Yeah, replaced it with a modified brand new one.
However I am being told here to remove thermostate since its tropical climate over here, that it wont cause any problem. any advise?

maqh said:

Yeah, replaced it with a modified brand new one.
However I am being told here to remove thermostate since its tropical climate over here, that it wont cause any problem. any advise?

Click to expand...

Did you remove the old thermostat at the back of the engine, when you fitted a new modified one?

There is a blanking ring which is fitted in its place (standard stat with centre wax bulb removed)

You can butcher the old stat, just cut out the centre (see post 4 in link below)

http://www.landyzone.co.uk/lz/f9/1-8-k-series-cooling-system-45025.html

Official LR part no - Blanking plate PEL000040, Thermostat seal PEF10010

How to connect up the modified thermostat PRT (post 88 below)

http://www.landyzone.co.uk/lz/f9/so-has-mine-had-thermostat-mod-not-210525-9.html

Was the cooling system thoroughly flushed?

Northern Irelander said:

Did you remove the old thermostat at the back of the engine, when you fitted a new modified one?

There is a blanking ring which is fitted in its place (standard stat with centre wax bulb removed)

You can butcher the old stat, just cut out the centre (see post 4 in link below)

http://www.landyzone.co.uk/lz/f9/1-8-k-series-cooling-system-45025.html

Official LR part no - Blanking plate PEL000040, Thermostat seal PEF10010

How to connect up the modified thermostat PRT (post 88 below)

http://www.landyzone.co.uk/lz/f9/so-has-mine-had-thermostat-mod-not-210525-9.html

Click to expand...

I'd check this out if it were me^^^