Mixing red & green coolant

[sid]

Bought a TD5 Defender last weekend and had quite a long drive in hot conditions to get it home from QLD to NSW. I was quite conscious of keeping an eye on the engine temp, as well as other bits and pieces as I didn't want to wreck it on my maiden voyage with it.

Anyhow, stopped in Charters Towers to check everything, and noticed after the engine had cooled a bit that the coolant level was a bit low, and so bought some green glycol based coolant to top it up. Since going through the receipts for work that were provided with the vehicle, I notice that in 2016 the radiator was replaced, and refilled with red organic coolant.

My question - I gather you're not supposed to mix these, for reasons I'm not entirely sure of. I used a clean coke bottle to top it up, so probably put 600ml of the green glycol coolant in. It this an issue? should I flush and refill the system, or is 600ml in the scheme of things a minimal amount and not worth worrying about? 'Tis a '99 TD5 with approx 265,000km on it.

I'll chuck some pics of the new rig up once I get sorted out.

thanks in advance

[bee utey]

Some coolants are chemically incompatible and when mixed produce a viscous gluggy mix that blocks everything. If that hasn't happened to you it's probably OK for now. Colour means little, it's just a dye. I find it better to top up with clean water on a trip and add the correct concentrate when you get home.

[trout1105]

It is better to just add some water instead of an incompatible coolant.
OAT and Glycol coolants are different.

[gromit]

As bee utey mentioned, the colour is just a dye, what you need to know is the corrosion protection type (OAT, HOAT, IAT etc.).
Mixing types could compromise the anti-corrosion protection but you'd need to be a chemist to work out how/when/if....

Most, if not all, types contain glycol because this is what gives it the anti-freeze anti-boil characteristics. So old school or modern long-life contain glycol.
The old school coolant was IAT (inorganic additive technology) but only gave corrosion protection for about 3 years.
OAT (organic additive technology) gives a longer life.
HOAT (hybrid organic additive technology) also gives a longer life.
There are a few other acronyms.

It used to be that green was IAT (old school), red was OAT but it isn't a 'given' and just to add to the confusion you now also have blue, pink, orange.......

With some brands you'll struggle to even find on the labeling what type of corrosion protection is used, I had to contact the technical department of one company to find out.


Personally I'd drain, flush & fill with a known coolant but you may not have any issues, hard to tell.


Colin

[bsperka]

I'd drain and flush it, then put in the correct coolant. That way you know what's in it from a maintenance pov.

[Dorian]

Drain and flush it in the near future.
My D2 had this done to it before I bought it and it caused me a few problems, as I didn't pick it up soon enough (like two services) . Notably it blocked the water to oil cooler (or is it oil to water) in the bottom of the engine.
The bit of research I did at the time indicated that the OAT makes the glycol gel.
I am pretty sure that OAT is the recommended coolant for the TD5 engine.

Cheers Glen.

Edit - a bit of googling shows that many of the green coolants are now a hybrid of Glycol and OAT. So it will pay to check the bottle and see what the formulation is.

[sid]

Thanks all - appreciated. Checked the container and it's a glycol based coolant that I've topped up with, so will flush out this weekend and refill with the specified stuff. Assuming there'll be a thread somewhere on here on how to drain the coolant in a TD5 so will seek it out.

[gromit]

As mentioned earlier, ethylene glycol is used to give the anti-freeze/anti-boil characteristics whether its OAT, HOAT, IAT, 'Conventional' etc.
You need to know what the anti-corrosion type is.

If it doesn't contain ethylene glycol it's just a corrosion inhibitor (or Type 'B' coolant). For example mixing Type A & Type B (with & without ethylene glycol) if they are both the same anti-corrosion type shouldn't be a problem.

http://www.penriteoil.com.au/assets/...5/Coolants.pdf


Colin

[Tombie]

Short story... drain it, flush it, refill it with the coolant of your choosing and don’t mix.

Some react quite nicely with each other blocking cores, sedimenting the block or radiator and some turn to sludge...

[sid]

Ok, thanks. I think I'm starting to understand the differences.

So I've found the bottle of coolant I bought in Charters Towers, which is Puma Lubricants HD Premium coolant 50/50 premix solution, 40-50% ethylene glycol. It states it is "a premium quality, organic, long life anti boil/anti freeze coolant, based on carboxylate technology and contains no silicates, nitrates or amines.

The reason I bought it at the time, is that it states that it is suitable for use where Land Rover Ethylene Glycol coolant is required. I guess the difficulty here is that the only thing I know about what was in the system now already is that it's a 'red organic coolant' as noted on the workshop invoice.

Am I safe here in assuming that the two should be compatible? I guess at the end of the day flushing and replacing is the best way to go to be certain, but I don't want to do it unnecessarily, and probably won't have the time for a few weeks anyway.