Thread: Which Coolant do you use

Nulon long life red OAT is available at all super cheaps

... and quite often K-mart has it in the auto section.

Don't use green coolant ... others may/might (with a complete flush and clean out to remove ALL traces of the old red OAT coolant as they should not be mixed).

... get the red OAT and play it safe.

Kev..

I am about to do all of the coolant hoses so I need new coolant as well.

What does OAT mean? please excuse my ignorance if I should know theis already.

Cheers

Matt

Nulon OAT Longlife its red. its available everywhere kmart auto sometimes has it but if they dont wont order it in specifically.

OAT
Organic Acid Technology.

Originally Posted by mattg

I am about to do all of the coolant hoses so I need new coolant as well.

What does OAT mean? please excuse my ignorance if I should know theis already.

Cheers

Matt

Most all coolants use ethylene glycol as the anti-freeze base, then an anti-corrosion (inhibitor) package is added.

Older type additive packages used silicates by themselves or in concert with nitrates.
These put a coating over all the reactive metal surfaces inside the cooling system to prevent corrosion, but deplete fairly rapidly.

Newer type coolants use carboxylate as the anti corrosive, which is known as an Organic Acid Technology coolant. OAT.
These only react with areas that are about to corrode and so keep the majority of surfaces 'clean'.
As a consequence their life is far and away much longer than older style coolants, something like 5 years vs twelve months, and a secondary benefit is that as they don't coat everything internally with a silicate, their heat transfer is better and as there aren't any nitrates, they don't abrade the pump seal or impellor.
As they are silicate free they also don't suffer silicate dropout.

However.

They can be touchy things too.
Any air leaks in the system and they can react badly, causing sludging.
One of the main constituents (can't recall it's name ATM) also acts as a plasticiser on some elastomer's (seal materials)
This is the cause of the dreaded intake gasket leaks in some V6 Chevs in the US.

Land Rovers OAT coolant used in the TD5 and V8's was developed by Texaco (Caltex here) and is identical to Caltex Long Life coolant, identified as utilising carboxylate technology on the bottle.

A third type of inhibitor package is known as a HOAT.
This is a Hybrid Organic Acid coolant, and incorporates the best of both coolant systems. There are a number available now, the most well known version used to be known as GO5.

Most coolant manufacturers make all types, and whilst I've used pure OAT coolants for years, they work really really well when a cooing system is in tip top shape, I tend to feel the HOAT's are probably a 'safer' long term answer, as do a few major manufacturers it seems these days.

Always, always use the same colour as the coolant that was in there.

I use Nulon (have both red and green in the shed, as my japanese cars use green). I don't like to mix different coolant brands, as I have read several articles to indicate that they can and do react with each other and the engine components.

Why Nulon? Its a quality brand (there are others, but I prefer Nulon) that lasts for a long time and for a change every three or four years it is more cost effective than the cheaper brands which last one year or perhaps two. I always reverse flush the engine and radiator and change all the hoses every 2 second coolant change (every 6 to 8 years), or when they start to feel soft, if within that timeframe. Whilst it won't guarantee that there will be no problems, it is cheaper than running an engine with a water leak.

Rick
the one you refer to is Nalcool, the GM derivative. Nasty pasty when it mixed with air. Is still the basis for all GM coolants now but has been revised somewhat after all the problems.
We stock theDetroit Powercool which is used in Series 60 engines.
Generally don't use unless specified.
Another option is the Cat ELC.

Cheers

Andrew

Originally Posted by LOVEMYRANGIE

Rick
the one you refer to is Nalcool, the GM derivative. Nasty pasty when it mixed with air. Is still the basis for all GM coolants now but has been revised somewhat after all the problems.
We stock theDetroit Powercool which is used in Series 60 engines.
Generally don't use unless specified.
Another option is the Cat ELC.

Cheers

Andrew

Actually the GM coolant is known as Dexcool, (basically identical to Land Rover OAT)
As you said it turned gunky with poorly sealed radiator caps and reacted with the seals on the intake manifolds on GM V6's and leaked coolant into the sump.

Cat ELC is the Texaco/Caltex LL (Dexcool, Land Rover OAT) with a couple of SCA's. (supplemental coolant additives, sorry for the acronym, I forget most wont know what the hell I was writing)
A CAT lab bloke wrote on another forum once what they were and the %'s (tiny amount) and it could have been a small amount of nitrate for cavitation errosion protection ?

The CAT stuff is bullet proof.

The funny thing is that the Caltex Long Life has CAT, MAN, Isuzu, etc approval too without the SCA's.