Coolant

[shane wescott]

Guys

Quick technical question and then opinion please.

What is the difference between red and green coolant ? I know toyota a generally use the red type but don't know If there is any real technical reason why.

And opinion - good brand coolant/strength for a GTV6 ?

Thanks in advance.

[Meng]

http://autorepair.about.com/cs/generalinfo/a/aa052601a.htm

Bottom line - use whatever it came with from the factory.

[colcol]

The green coolant is used more in motorsport applications as it usually doesn't contain Glycol, the green coolant is less slippery and dries quicker if spilt on the track, i use it in the 33, the brand i use is Nulon, but all brands complying with the Australian Standards should be good.
The red coolants and sometimes orange coolants have an OAT agent that stops any baterial growth in them and are longer life than the green coolants and are not reccomended for motorsport, i use Nulon Red coolants in my 156, they are also used in all alloy engines such as General Motors alloytec V-6 and the Gen 3 V-8 alloy engines, but as all coolants must be changed on time, as with age they turn acid and can corrode your engine, Colin.

[Beatle]

Not true Col.  Green glycol coolants have been around for eons (e.g. Castrol).  Colour is no guarantee of the chemical cocktail, so read the label, and the specs/MSDS sheet.


I used to use blue coolant on my bike, cause it matched the plastics..............

 

[colcol]

The colors i was refering to was Nulon, which i use cause its easy to get at the usual auto places, i didn't know about the green Nulon being ok for motorsport....until i read the back of the bottle.
The blue coolant sounds very different, never seen it before, the red Nulon coolant in the 156 is very flouro, when it started to leak out of the 156, it was very easy to track down the problem area.
The green Nulon coolant is also very bright and when it wears out it becomes very dull, to remind me to change it, Colin.

[Steve S]

Coolant is actually colourless, it is coloured by the manufacturer any colour they want.  So make sure you read the bottle to know what you are buying and don't just buy by colour. There are 2 main types of coolant, type A which is an antifreese/antiboil also with a corrosion inhibitor and type B which is a corrosion inhibitor only. Type B is the stuff suitable for racing.

Type A contains Glycol for antifreese/antiboil and all sorts of additives for corrosion inhibition. Its it the corrosion inhibitors used in the coolant that determine the "performance" of the coolant. There are 2 main groups, traditional and organic "OAT".

OAT additives are generally better, they last much longer and give better heat transfer properties over traditional. They are however not compatible with all metals used in cooling systems over the years, I think tin, copper etc. They are suitable for most modern alloy engines with plastic radiators.

I don't know if you can buy straight Type A traditional coolant as it has been made obsolete by hybrid "HOAT" additives which is some sort of mixture of both traditional and OAT. These offer some of the benefits of OAT but retain maximum compatibility. Although it's not recommended, they can also be safely mixed.

So I would recommend a HOAT coolant, I know Nulon and Penrite both offer these and they are coloured green.

[shane wescott]

thanks for the replies guys.

I use penrite oil so will prob go with that.

I have learn quite a bit from this - thanks once again to the knowledgeable peeps on this forum :-)

catch ya

Shane

[MD]

Just a couple of points that don't seem to have been covered.

Coolants are available in premixed or concentrates. That in itself is not an issue. The central issue (other than overheating, corrosion and ice triggered fractures) is mineral deposition that comes out of solution from tap water.

This is the stuff that forms an insulation blanket inside every radiator tube, every runner and covers every liner. Once formed, it causes an impediment to heat transfer diminishing the cooling designs planed for your engine.Build up also cause blockages. Depending on the extent of deposition, (minerals in solution around Australian drinking water supplies vary so much that it is impossible to legislate for a uniform drinking water standard.) it could simply see temps rising to complete boiling due to various degrees of blockages.

The simple lesson here is to always prepare your own mixture from a concentrate and ALWAYS use distilled water.

Avoid premixed solutions as invariably they will be made using tap water unless otherwise stated.

Don't be tempted to use rainwater as it has a pH of around 6.5 making it acidic.

Good time to check those neglected heater hoses. Pressure test the system for leaks.(including head gasket leaks). Water pump bearing and seal condition and Mr. Faithful, the radiator cap for correct pressure and sealing.

I hope the crabs fish are on the bite Shane..

[Beatle]

MD, good points.

I find distilled water considerably cheaper in the cleaning aisle of a supermarket than at auto parts stores.  Same stuff.  Keep it on hand for coolant and battery top-ups.  Tastes like sh%$t but you can live on it.................

And always stick with the type (if not brand) of coolant recommended by the vehicle OEM, particularly in newer vehicles (post 19995-ish).   For example, if you use a green glycol coolant in a Toyota Landcruiser (80 series-on) it builds up a thick honey-like substance in the radiator that can't be flushed or chemically removed.  It doesn't seem to eat the rad out, just clogs it.

Others have told me you should also reconsider your coolant if you change the radiator material from original.  So if you drop a brass/copper rad into a car in lieu of a factory aluminium/plastic rad, it can change the galvanic processes and turn into a big battery.  I have no science on this (but seems logical) so make up your own mind on that one.

[MD]

So if you drop a brass/copper rad into a car in lieu of a factory aluminium/plastic rad, it can change the galvanic processes and turn into a big battery.

Mr Super that is correct. So the additional advice to anyone using a traditional radiator ie, brass tanks with copper core, it is very important to fit a ground connection between the radiator and the engine block to negate that problem. It's not so much that it acts like a battery but importantly that it promotes internal corrosion of your cooling system.

If you haven't yet installed one on your flying brick, you need a pull through with a rough end of a pineapple for a wake up call... ( I just know you got a sense of humor buddy.)

[Beatle]

I'm afraid the rough end of the pineapple should be self-administered.  I sold the Suiper some time back...............
(I really should update my avatar)

[MD]

You SOLD THE SUPER ?. You SOLD THE SUPER ??.

You sold the the most significant and interesting sedan of the 20th century not to mention the best sedan Alfa ever made?

That's it. I am sending you a crate of pineapples..

(Sorry about the detour Shane.)

[Steve S]

Coolants are available in premixed or concentrates. That in itself is not an issue. The central issue (other than overheating, corrosion and ice triggered fractures) is mineral deposition that comes out of solution from tap water.

Don't be tempted to use rainwater as it has a pH of around 6.5 making it acidic.

Wow, I would have thought manufacturers would definitely be using distilled water in their premix coolants, at least the premium brands. I have never checked the container for that.

Coolant has a buffer to neutralize acids, however it will reduce to life of the coolant if you use acidic water to start with.

[MD]

I

would have thought manufacturers would definitely be using distilled water in their premix coolant

Steve,
I worked in the UK for a while. I had an Aussie friend that worked in a service station that sold bottled drinking water. Her job was to fill the empty plastic bottles out of the tap and put them on the shelf to be sold as bottled drinking water. The boss used to buy empty plastic bottles in bulk for the purpose. Great profit margin !

The moral of the story here is that if you can do the job yourself, don't be lazy because the outcome will be in your favour provided you know what you are doing. In the case of coolant mixing, if someone cannot make up a 33% concentrate solution to distilled water then our education system is far worse than I ever imagined.

If you want to confuse yourself even further about coolant additive, check out Water Wetter info here:
http://www.thetruthaboutcars.com/2008/01/redline-waterwetter%C2%AE-review/

[Steve S]

People buy bottled water mainly because it is convenient, not because it is "better" than tap water. I don't have a problem buying bottled tap water so long as the seller is not trying to defraud you.

Maybe I'm just naive, however I'd like to think I'm just less cynical because we need to let go at some point.  When I go out to a restaurant, I'm not going to cook my own dinner just to make sure they wont spit in it.

Water wetter has its place, in race cars that can't run glycol. Somehow it leveraged its reputation for performance to move from that legit application into just another snake oil to sell to the general public where it is of no use whatsoever.

Although I have never actually purchased premix coolant I think it has a place. Id draw the line at premix washer fluid though!