Thread: TD5 Coolant - Was red now it's green.....

Originally Posted by Ricey

Last year I got the coolant changed, they chose to replace the pink oat with the regular green. The Thermostat wasn't open or something similar during the change & I ended up with a mixture of them both. After a few days it went black. Got it changed back to pink oat straight away.

Pink and green......it would have looked like rust lol

Then of course you get the green version that goes a re / purpley colour when it is due for a change, just to confuse issues more.

So is the Nulon Red good enough??

Or should one go the texaco/LR OEM? or other?

JC, what brand do you use??

the nulon red is on spec for use as the OAT in the td5... (its what I use when Im not using the CAT stuff)

Good timing.Today our water cart came in with overheating problems,it has always run OAT,the thermostat was rusty and the core rotted,I also had some spill on my chest removing the rad and it was like acid on my skin.I had the rad taken to another specialist in town(we have a work account with them) and he doesn't like OAT either,thats two that don't use it. Pat

Sound like the concentration was incorrect, therefore it would be super corrosive - No wonder it ate your cooling system alive. As I posted earlier in this thread, 50% concentration is specified by LR.

The same OAT coolant is specified for Jaguar.

50% is the maximum concentration and at that concentration if its been put into a system thats less than brand spanking new it will eat it up.....

33% is about the % I run it at and so far, touch wood, my system remains sludge and floaty free

OAT works the opposite way to the standard glycol stuff

with the glycol too little is dangerous and too much isnt so bad (Im not talking running it pure Im talking using say 50% as opposed to 40%)

OAT too much is bad and too little isnt so bad (again Im talking 20% as opposed to 30%) The side effect of it is a lower boiling point of the fluid and it doesnt last as long before it looses its ability to do what its ment to do.


This is part of the reason why most places sell coolants premixed (the main one being is that the pre mix stuff is up to say 80% distilled water and waters a hell of a lot cheaper per volume than coolant so they get a bigger profit margin)


Ive also had some people (guys whose opinions that I generally take seriously) tell me that if you get combustion gasses into the OAT the Exceptionally nasty things can happen... The logic is that it doesnt matter what coolant you use if you toast the head the heads stuffed BUT the Oat reacts with the gasses and then procceds to be nasty to things like radiator cores and oil coolers where as the stock glycol wouldn't.

Thinking back on it Ive seen enough TD5's that have done heads on OAT and then after being repaired have taken out one or more of the coolers fitted to the engine to be thinking "Hang on, there might just be a pattern here"... Its not evident enough yet to make me change my mind on the OAT v Glycol issue as Theres not enough evidence to make me believe that the OAT (used correctly) took out the head.

Originally Posted by catch-22

So is the Nulon Red good enough??

Or should one go the texaco/LR OEM? or other?

JC, what brand do you use??

We have used a 'Prixmax' branded Hybrid Organic compatible Glycol based coolant for 6 years now without any issues. I spent considerable time initially searching for a coolant that would suit ALL the different vehicles we work on, Which apart from all LR products old and new, includes Volvo, Saab, Jaguar, Mercedes-Benz, (even buckets like Commodores and Falcons, although I try to stay away from THOSE...) to avoid having different types in stock for different vehicles etc.

This stuff exceeds all European and US trucks specs too, including Cummins engines, which are very cautious about their coolant choices.

(edit, To add also that when the above is unobtainable, a 'Motocool' as a substitute has proven fine also)

JC