Coolant Spec

[poloag]

Hi,

Is G13 the correct spec for our cars?
If so what is the Comma equivalent please.

Thanks

[RUM4MO]

Your car probably was filled at the factory with G13, but that coolant has been discontinued and replaced with G12evo, there were some issues with some engines using G13 and that lead to Silicate "crystals" being placed inside a porous "tea bag" in the reservoir so that extra Silicate was being dosed into the coolant to counteract the lose of Silicate in the coolant - the silicate is used to protect some surfaces from corrosion.

It seems that with G12evo this issue no longer exists, so, I was monitoring one of my cars which was filled with G12+ or G12++ for loss of protection, ie the change of the ph towards being acidic and I did the same with my wife's 2015 Polo filled with G13, the G13 moved towards being acidic quicker than the older G12+ or G12++, I do plan to change the coolant in my wife's 2015 Polo soon and refill with G12evo.

When you look on aftermarket supplier's websites, you invariably find that the coolant that was used at the launch of a model is the version of coolant that they advise for topping up and refilling, so that means Comma's brand name for the BASF coolant that VW Group call G13.

[poloag]

interesting thanks, so if I went to the VW dealer would they give me G13 or G12evo?
Is G13 Comma version ok to use to replace the coolant?

I did a search on a few websites with my reg and they recommend G40 Comma which is G12++ (tl-vw 774 g)

G13 and G12++ is recommended in book.

You are right G12evo:

https://www.coxmotorparts.co.uk/vw-shop ... -litres-2/

thanks

[RUM4MO]

If you went into any VW Group dealership's parts department then the only VW Group branded coolant being offered for sale will be G12evo, it replaces the previous G12, G12+, G12++ and G13 and mixes well ie is compatible with them, any warning given is just to point out that if you add say a litre of G12evo into the car's coolant system, then you still really only have the protection that the legacy, ie present before you added anything into it, levels of protection - but that should not be a worry.

My way of looking at this whole VW Group coolant change/evolution thing is, as time goes on, the coolant industry advances and improves their offerings to the motor trade, I strongly suspect that when the "tree hugger's" version, ie G13 was launched, or rather BSAF launched their new coolant which is all that this G13 is, all was well with the world - and then for some engine uses, where intermittent higher than expected by BASF engine temperatures "existed", a bit sneaky bit of back pedalling had to be done, and so certain engines/cars were fitted with these Silicate pouches, and that sorted that out - but, oh no, another possible issue "appeared" and that possible issue was that the cheap and nasty pouches, ie like teabags started opening up in the coolant systems and that did tend to end up with the heater matrix and any other area with very small coolant flow bores getting chocked! This was or could be a problem for the owner, but it turned out to be a joy for the workshops, ie a new unexpected source of work and so revenue!

So, so far, or at this time, I aim to change from G12+/G12++/G13 when convenient. I have already done that to my 2011 Audi S4, and hope to do the same to my wife's 2015 VW Polo soon.

All this is just my thoughts about this and what action I should be taking, nothing more.

[poloag]

thanks for comprehensive answer.
I wonder if the g13 was responsible for the water pump failures too.

[RUM4MO]

thanks for comprehensive answer.
I wonder if the g13 was responsible for the water pump failures too.

I'd doubt it, more likely that the plastic housing warped/deformed and caused a coolant leak from that large pump/thermostat lump of plastic - though I could be wrong.

Edit:- by the way, if it was a VW Group dealership workshop that replaced that water pump, they would have refilled the system with G12evo depending on when the pump was replaced.

[poloag]

so when you replace the water pump do you need to replace the housing too?

[RUM4MO]

I have just edited my previous posting.

I suppose it depends on who carried out that work, I'd expect a proper VW Group Indie or a VW Group dealership, to just replace everything to avoid another early failure - I'd need to check the parts listing to say "absolutely", but I'd guess that that complete assembly is available as one, though maybe, just maybe only as a water pump plus new seals.

Hopefully most proper workshops realise the nature of modern plastic mouldings and their poor performance in service on car systems, or some car systems.

[RUM4MO]

I've checked the parts listing and the "coolant pump" comes complete with all the "coolant regulators" that live within the large plastic lump that the coolant pipes connect to, but it can be split up and some items like new gasket seals replaced and new coolant regulators.

So, in reality, an after market actual sub unit that is only the coolant pump, could be replaced by itself, that would be a cheaper fix for a bored DIYer, but I'd think that the extra labour costs to take this approach by a professional workshop would out weigh the difference in price of buying a complete unit and offer the better solution for a workshop, ie less chance of bad press from trying to save the planet and wasting a customer's time and money.

My personal approach to this would be to buy in a VW Group complete assembly and fit it - and keep the old one in a "safe place?" - well maybe after a few months I'd strip it for spares and bin what was broken/failed!!