K Series ally radiators

[Wrightpayne]

Reading Roger's post means I've had the wrong coolant in for 22 years considering I have a copper radiator! Oops!!

[Foggy]

When I spoke to Darren at Radtec he advised me to use blue IAT anti freeze diluted with de-ionised water in a ratio of 15 - 20% as this would avoid the corrosive crystals in red OAT based anti freeze.  I have since read that Rover advised the use of OAT based anti freeze in the k series yet Rogers post seems to suggest that IAT is safe for all metals and would therefore seem to me to be the way to go in my case ............ or have I missed something?

 

 

[StevehS3]

#27 Exactly, that is why I raised the point. 
Rover and Caterham say OAT and some rad manufacturers say IAT.

Then there is this:
What is best for performance use?

It is always best to use the engine manufacturer’s advice.

[Foggy]

I wonder, has the age of the vehicle have any bearing on IAT or OAT?

[ECR]

What isn't made clear is the consequences of using the wrong antifreeze in a yellow metals system. If its been used for 22 years in a yellow metals system (above) what has it done? Does it eat away at the yellow metal or does it produce some harmful mixture which affects all the other metals?

[Wrightpayne]

Looks like Comma G48 is the IAT / silicate variety.

[John Vine]

...the corrosive crystals in red OAT based anti freeze...

Intriguing. Did he say what they were?

...has the age of the vehicle have any bearing on IAT or OAT?

Very much so, I would imagine, if by age you mean the engine design and construction. 

IAT coolants are intended for the older engines and cooling systems that may well contain iron as well as yellow metals such as brass and copper (and solder too, I believe).  OAT coolants are intended for the more modern all-aluminium engines (like the K).  A bonus is that the OAT inhibitor package lasts longer -- typically five years -- compared to the two-odd for IAT products.  There's been quite a bit of bad publicity about certain inhibitors found in some OAT coolants, notably 2-EHA (2-Ethylhexanoic acid) which has been found to have an adverse effect on some silicone hoses and seals due to its plasticizer properties.

JV

 

[Wrightpayne]

Oh joy more good news!

any chemists / metallurgists available to comment? 

[Wrightpayne]

Another thought - heaters have a copper core too - plastic bodied ones with 7 on the front, late 90's era.

[Foggy]

Have just come across this response discussing the use of Blue/Red anti freeze on another forum by a certain highly respected k series guru.............

“OAT coolant was only specified for the K series after 2001 and this was more about restricting pollutants rather than any benefits endowed on the engine or cooling system efficiency. Polypropylene or Ethylene glycol based coolants are perfectly OK provided you don’t mix with OAT.”

My car being 98 vintage it seems that “Blue” will not only satisfy Radtec’s requirements but more importantly, won’t harm my engine! 

[7 wonders of the world]

some of the senders have brass bodies too....

[John Vine]

Polypropylene or Ethylene glycol based coolants are perfectly OK provided you don’t mix with OAT.

I don't quite follow that.  It suggests that PG and EG coolants always use IAT inhibitors, whereas they can use IAT or OAT inhibitors - or sometimes both, as in the case of the hybrid OAT coolants.

ETA: It's propylene (the monomer) not polypropylene for the glycol used in coolants.

JV

[Wrightpayne]

So what do I do - currently has G30 in it??!!

[John Vine]

Stick with G30.  Comma/Glysantin G30 is recommended by the manufacturer for the K (in fact, all Rover engines from 1982).

I used it in my K and it's in my R400D as well. 

JV
 

[Foggy]

But surely if IAT is suitable for the K series engine and ally rads is that not a better option all round?

[John Vine]

Re #40:

From what others have reported, I imagine that IAT and OAT coolants will both work OK in a K, but the OAT ones are considered to offer superior corrosion protection in aluminium engines.  By extension, that would suggest that OAT coolants are also superior in aluminium radiators.

Did Radtec explain why they recommend IAT coolants for their aluminium rads (apart from the vague "corrosive crystals in red OAT based anti freeze")?

JV

[StevehS3]

Just a thought, are Radtec radiators an aluminium alloy with elements of copper (and therefore unsuitable for OAT coolants?)

[Foggy]

John & Steve, I have to speak to Radtec tomorrow so I’ll see if I can’t find out precisely why IAT is good and OAT is bad. 

[TomB]

I’ve got on on it way too - I currently have pink Bluecol stuff in the car. I was thinking about diluting the pink stuff down more, given that the car is well garaged in the winter and it’s supposed to be better for the engine. 

[Foggy]

Good morning all, I have had a chat with Darren at Radtec as to why Blue and not Red.  Apparently and this is their theory only but based on evidence of rads that have been returned, Red has been known to attack the braze used to attach the tubes to the header plate.  They also have photographic evidence of red congealing within the rad.  Having said that, Darren then explained that these faults only seem to appear with cars that spend long periods of time static (ie over winter).  They haven't come across the same faults with blue but recommend a diluted ratio of 10-15% with de-ionised water.

As regards the affect of blue v red on the k series engine, they have not heard of any problems using blue on any engine so tend to stick to blue.

[John Vine]

Re #45:

Thanks for posting that.  I guess it all depends on what metals their brazing filler contains.  I'd imagine that the presence of copper, for example, could well cause problems with an OAT coolant.

Any aluminium brazers or welders out there?

JV

[TomB]

Ive got pink coolant in, sounds like I should change back to blue.  Is there a way of getting all the pink out without taking the thermostat out?   

[7 wonders of the world]

Interesting as CC supply Radtec and use OAT coolant

I run Triple X red OAT in my Duratec with Alicool rad with no issues.

Speak to Alicool and see what there take is.....

[Drumster]

I've used Comma G30 in both of my Radtecs. The first one showed no signs of weeping after 4 years when it was written off in an accident. The replacement is coincidentally also ok after 4 years........ No idea it if makes a difference but I tend to flush the whole cooling system when I replace the coolant.

[RogerB]

Thanks for this post which is pertinent to me as I changed from an alloy radiator to a copper cored one. However I didn't change from the OAT antifreeze. I don't suppose you know where the harm would occur by using the wrong type of antifreeze. Also is it just a case of flushing out with water when changing over to IAT ?