Is mixing different coolants REALLY bad?

O

OldSkodaDriver

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I just topped up my Skoda with coolant: BLUECOL'u' clear.
It said:
'Universal top-up antifreeze & coolant'
'All makes - All Models'
'Will mix safely with all colours of antifreeze'

Then I dug out the manual which states:
'The same coolant (G12) (red in colour) MUST always be used for topping up.'
'Mixing different coolants can result in damage to the engine'
'Have the coolant replaced immediately'

Is this true?
Thanks.

2002
Skoda
Fabia
1.4
40,000 miles
 
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I have heard of problems with mixing different types of antifreeze, if you mix a modern organic type with glycol it coagulates.

Not experienced it myself though. There is a table somewhere of which antifreezes will mix but I'm afraid I can't remember where I saw it. I expect John will know.

Peter
 
OldSkodaDriver said:
2002
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Over the years, technology has moved on. My car also says I must only use a particular coolant in a particular colour (it was one of the early organics). But the company that made the engine now offers a coolant in two different colours that it says is suitable.

The cheap old Blue antifreezes were not suitable for mixing with the Organic formulae, and as they are still sold, you need to have a look at the information panel on the container. The label you quote says it is a formula that is OK to mix. The "U" stands for "Universal" See also http://dev.bluecol.co.uk/products/anti-freeze-page/

The Red organic ones are supposed to be better and last longer, but are not suitable for some older cars.
 
I wish I knew the absolute answer to this one....its a case of not mixing glycol coolants with organic acid ones (OAT) but when you consider that they have similar component parts you have to wonder if there's just a bit of sales hype here.
Anyway, I've mixed the 5 year red stuff with G12 and have had no issues (Mannoil is the preferred make for me just now) and when you consider the extortionate price for G12 who can blame me! I don't use the 2 year coolant at all.
However, if I was draining the complete system or replacing a water pump say, I'd just use one 5 year brand.
The Skoda should have a drain plug at the bottom of the radiator anyway which is a bonus!
John :)
 
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You can't (or at least aren't supposed to) mix "OAT" (Organic Additive Technology" with "IAT" (Inorganic Additive Technology) antifreezes. They form a sediment that can block radiators and heater matrices. HOWEVER, I'm sure I've read somewhere that this was only the case when OAT types first came out and that now, the concentrations of each have been reduced to the point where that won't happen. I've certainly done it to a limited extent, with no ill effects. That said, it reduces the life of your mixture to the life of the shorter of the two components in the mix.

The newer stuff (OAT) can't be used in cars with "yellow metal" in the cooling system (brass or copper, typically). The older IAT stuff is fine in either (but needs changing more often). A good flush Including heater matrix) is advised if swapping from one to the other.

Good info on it here:

http://www.alfaowner.com/Forum/engi...6301-coolant-andamp-antifreeze-explained.html
 
I guess the yellow metal would be the old type thermostats.......I can't think of anywhere else.
People need to be aware that the antifreeze qualities of coolant lasts much longer than the corrosion inhibitors - hence the need to change it at the required intervals.
John :)
 
Yes, but possible copper tubes in radiators (if any cars still have those?!) or even end tanks. Likewise copper in the heater matrix. I don't know if any cars have brass impellers on their water pumps? I know my car has a brass bleed plug in the top of the thermostat housing.
 
Thanks for eveyone's input.
As I only added a small (.25L) of the BLUECOL'u' clear Im hoping that I will get away without issue!
But I will get some of the 'right' stuff for future additions.
Cheers.
 
I think, now you've contaminated the existing antifreeze, you may as well change the lot, really.
 
I'm sure everything will be just fine.... its unusual for the level to drop any significant amount so maybe our colleague needs to keep an eye on that.
John :)
 
We can hope the car being 14 years old didn't have the original antifreeze in it so there shouldn't be any ill effects
 
JohnD said:
But the new antifreeze is "U" universal, and compatible with what was there before.
Click to expand...
AH! I stand corrected! I've just done a few searches, and it does indeed seem to say that this stuff IS compatible with either sort of antifreeze! I've learned something today! Also DaveHerns makes a fair point. At that age, there's nothing to say which sort of antifreeze would have been in it anyway.
 
It must have had a cambelt and water pump by now at 14 years old, you'd hope!
 
Thanks again for all your replies:

Here is the reply I got (very quickly) from the manufacturer:

'Bluecol ‘U’ has been tested with coolants such the G12 type and is fully compatible to use with this product therefore you should have no worries regarding the formation of any deposits that would cause problems in the cooling system.


Regards,


Shazad Shah

Product Manager - Lubricants & Winter

Tetrosyl Ltd


Tel: 0161 762 6623
 
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