Range Rover P38 GEMS cooling system

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unstable load
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Range Rover P38 GEMS cooling system

Post by unstable load » Wed Feb 08, 2017 5:26 pm

I need to run an idea past the collective brain, please....

My P38's thermostat just sprang a leak and while I was draining the coolant out, I had a good look at the over complicated non replaceable, all-in-one set-up they have and my mind turned to why the hell did they do this?
The 'stat is in a plastic housing and hidden way down low on the radiator, presumably because the water is cooler down there and the plastic won't fail prematurely at the high temps the 4.6 runs.

So, my question is this...
Can that plastic housing be done away with and a 'stat fitted in the "normal" location at the front of the inlet manifold?
If yes, then
1...What changes need to be made to maintain the correct flow for bypass through the heater element?
2...What will the effect be on the ECU and sensing temp for fuel mixture?
3...Will I need a different temperature rated 'stat?
4...Is there anything to be gained by running the engine cooler and if so how do I go about that?

Here is a diagram of the flow....
[img]https://www.landyzone.co.uk/attachments ... jpg.65691/
and here is the front view of the engine....
http://s270.photobucket.com/user/nickm3 ... 4.jpg.html


Cheers,
John

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ChrisJC
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Post by ChrisJC » Wed Feb 08, 2017 9:35 pm

Sounds like a lot of bother to change something that works really well!

Chris.
--
Series IIA 4.6 V8
R/R P38 4.6 V8

unstable load
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Post by unstable load » Thu Feb 09, 2017 6:31 am

You know what they say about idle hands, Chris.... :lol:
Cheers,
John

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Re: Range Rover P38 GEMS cooling system

Post by Haggisbiker » Wed Jul 25, 2018 12:10 pm

The first time I looked at my thermostat on my P38 thought it was a bodge someone had done because it has two ears with holes for securing it down but on the P38 it just floats between the rubber hoses!

I changed one and in all honesty not had temp issues but will say I added stuff called watter wetter to the antifreeze as it is meant to keep the temps down a bit...even in hot days and still having the factory viscose fan it never goes above the mid point on the temp gauge even when towing so guess something is working!

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Re: Range Rover P38 GEMS cooling system

Post by ChrisJC » Thu Jul 26, 2018 4:23 pm

The thermostat should be located into the fan cowling at the bottom.

The temp gauge on a P38 is a total fraud. It is 'fixed' to point due north between about 70 and 120 degrees! You have no idea from the temp gauge what temperature the engine is actually at, so you can't tell if water wetter has helped.

I think you can be sure however that if everything is working as Mr. Land Rover intended, there's no need for any special additives!

Chris.
--
Series IIA 4.6 V8
R/R P38 4.6 V8

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