TD4 Thermostat Mod - 83° or 89°. Pros and Cons?

kernowsvenski said:

I'm about to embark on the thermostat mod for my TD4 auto. There is a fair bit of info on here about it but I'm wondering about a definitive discussion/summary of the pros and cons of the two different temp options that seem to be most widely used.

Is the 83° or 89° preferred?

Click to expand...

I've done an electric fan conversion on the missus's Disco 300tdi, the switch I used had two positions, 82° and 88°, setup for dual fans. I've got to say in that vehicle it ran OK on the 82° trigger point switch, but it runs signifigantly happier on the 88° setting

What’s the best one to buy?
Thanks

What’s the best one to buy?

Click to expand...

don't know re: "the best"
but here's one ..
https://www.landyzone.co.uk/land-rover/td4-thermostat-mod.350520/#post-4659099
site states 89c .. one i got appears to open at 85c ( via live data reading ) ..
works fine ..

~~~~~~~~~~~~~~~~~~~~~~~~~~~

hd3 said:

site states 89c .. one i got appears to open at 85c ( via live data reading ) ..
works fine ..

Click to expand...

Thermostats are rated at the fully open temperature. So an 89°C stat would start opening at several °C under that. The TD4 is thermally very efficient, so will be adequately cooled by a partiality open stat, hence the engine running at 85°C, even with an 89°C thermostat installed.

Thermostats are rated at the fully open temperature. So an 89°C stat would start opening at several °C under that. The TD4 is thermally very efficient, so will be adequately cooled by a partiality open stat, hence the engine running at 85°C, even with an 89°C thermostat installed.

Click to expand...

cheers for that info .. be of interest
( also what you wrote re : rain-x ..
( always wondered why it caused smearing
( though the screen-wash version i'm using now seems to work ok .. 'n no smearing

enjoying the result of new thermostat ..
engine seems more consistent with regards to go-pedal response .. ( subtle difference )
and fuel gauge needle be dropping slower by comparison .. yet to calculate actual mpg

~~~~~~~~~~~~~~~~~~~

hd3 said:

don't know re: "the best"
but here's one ..
https://www.landyzone.co.uk/land-rover/td4-thermostat-mod.350520/#post-4659099
site states 89c .. one i got appears to open at 85c ( via live data reading ) ..
works fine ..

~~~~~~~~~~~~~~~~~~~~~~~~~~~

Click to expand...

Bought one recommended by the MG owners
( I think the they like it for the free jubilee clips )
But true to form it’s running at 11:50 tonight on the way home !
It’s been running at 10 so it needs doing thanks for your time and I updated when fitted