Stuck thermostat inline mod

This site contains affiliate links for which LandyZone may be compensated if you make a purchase.
A

Adam131

Member
Posts
38
Location
Norwich
Hello all, looking for some support after buying a freelander 2005 manual TD4. For the last week I’ve noticed the temp not getting up to half and cold air on the blowers, to help the issue I have installed the modification of the inline Renault thermostat.
What I have noticed since I have installed it and done its first run up that there is no longer any flow of coolant back to expansion tank like I had before the modifications, systems been bleed etc. instead on idle for 15 mins there no signs of anything other then a very tiny move on the gauge , I done a quick 2 mile around the block and by the time I got back to drive way the gauge was up to half and hot air finally, still one issue there, still no flow what so ever of coolant back to expansion tank, I squeeze top hose and there defo no block as it feeds the expansion tank from little hose.

Does anyone have any ideas ? Or suppport they can offer, mines have to FBH removed so keen to get de icy heat in early morning , had my landrover diagnosed linked up and coolant temp wasn’t going about 85 degrees .

Cheers Ad
 
I remember reading a post somewhere on here, sometime ago, that you can put the thermostat in the hose the wrong way round, which I suppose could explain the problem?
 
Thanks , no about to do a 15 mile round trip so will check once home, the gauge has been sitting at half every time now which is good as I’ve not had heat before and don’t have heated screen. I double checked before install and it’s defo the correct way round
 
Just add, even last night night when it was fully up to half way temp and blowers red hot there was still no flow at all to expansion tank , however when I squeeze hose I could see the red flow again so I’m a bit mythed, could this cause damage if there isn’t flow
 
Hello, so just an update, complete a good drive this morning, gauge up to half as expected but thermostat on top hose has still not opened, and still nothing to expansion tank. Linked my diagnostic whilst driving and coolant temp would not exceed 86 degree, hence why I don’t think the thermostat is opening. What’s a normal running temp for the TD4 manuals? Should I see an increase in temp ? Concerned they maybe be a pressure build up before the thermostat as there obviously no flow to the rad.
 
Adam131 said:
What’s a normal running temp for the TD4 manuals?
Click to expand...

Screenshot 2025-01-16 at 20.06.45.png


[ original stat. spec ]
...
source :
www.landyzone.co.uk

freelander td4 m47r manual

workshop manual rover 75 BMW47 td4 diesel 2.0
www.landyzone.co.uk www.landyzone.co.uk
...............
i've the in-line stat.mod.. td4 manual. ... [ original failed 'open' ]
stays at 85c/86c normaly ..
last time i observed ..
i think it opens at aprox. 88c .. [ am using a 'scangauge.II' ]

.........................................
 
On the TD4, if it’s all working correctly you would see an obvious change once you did the mod…

The old stat (that generally fails ‘open’) will only allow the engine to get to around 1/4 on the temp gauge. The mod inline stat, you should see the temp gauge get to around 1/2.
 
Ok thanks Freddie, the mod has worked, and gauge at 12 o clock, my concern was just that I’ve not seen any flow back to expansion tank, and even this morning drive I can’t get temp above 88 degree to even open the inline mod. She’s been running so well I just don’t want her to get worse with this mod . Thanks
 
My rover 75 inline mod has full flow, the temp gauge gets to 12 o'clock VERY quickly. BUT, I did remove the standard TD4 thermostat too to improve the coolant flow. Yes it was stuck open but for me, to leave it in situ seemed very foolish.
 
Kerlaan said:
My rover 75 inline mod has full flow, the temp gauge gets to 12 o'clock VERY quickly. BUT, I did remove the standard TD4 thermostat too to improve the coolant flow. Yes it was stuck open but for me, to leave it in situ seemed very foolish.
Click to expand...
Most leave in situ due to the awkwardness of getting to it on a TD4, hence doing the mod work-around.
If you are going to the trouble to get to it to remove it, then just replace it anyway.
 
Adam131 said:
Ok thanks Freddie, the mod has worked, and gauge at 12 o clock, my concern was just that I’ve not seen any flow back to expansion tank, and even this morning drive I can’t get temp above 88 degree to even open the inline mod. She’s been running so well I just don’t want her to get worse with this mod . Thanks
Click to expand...
There will be minimal flow through the small pipe once the inline mod is done, except once the thermostat opens.
The small bleeder pipe is before the factory thermostat, as the factory stat is on the return from the radiator. The inline mod is on the flow to the radiator, so blocking up the small return to the expansion tank until the new stat opens.
You can restore the flow by drilling a 3mm hole in the new thermostat body, and positioning the hole at the top when fitted, so adding a tiny bypass for bleeding air out the system. This does delay heating up a bit, but also allows the system to maintain its self bleeding design.
 
I’ve tried 2 new ones just to make sure I didn’t have a faulty one. Il try one with the 3 mile drill to the body. Will also help if I can get the engine coolant temp above 88 to open it.
 
Adam131 said:
I’ve tried 2 new ones just to make sure I didn’t have a faulty one. Il try one with the 3 mile drill to the body. Will also help if I can get the engine coolant temp above 88 to open it.
Click to expand...
Don't worry it will open once the winter temps rise a little, case of making the engine work harder maybe stay in 3rd gear when knocking about
 
I put a pilot 2mm hole in one and what happened was that the temperature was lower due to bypass. Also, when the engine cooled, on down hill runs etc then the temperature dropped.

I filled the hole and all good. Not sure if mine shows a flow to header, I will check when next out in it.
 
You must log in or register to reply here.

Similar threads

H
Bubbles in the Coolant tank, no oil mixing. Landrover Freelander 1 Te4
Replies
3
Views
233
Ross Tait
R
S
Coolant level, defender 90 1989/200tdi conversion, Metal expansion tank.
Replies
2
Views
405
sdelasal
S
Andy Warren
Freelander 1 Jatco auto g/box oil & coolant temps
Replies
11
Views
1K
Andy Warren
Andy Warren
S
Coolant leak overflow
2
Replies
25
Views
2K
sierrafery
sierrafery
Bife
Freelander 1 Oil Cooler
2
Replies
28
Views
2K
Bife
Bife
Back
Top