Topping up coolant - 2017 Leon Cupra 300

QTom

Active Member
Sep 22, 2017
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Had a warning light come on yesterday, I believe it said "Check coolant! User manual!"

I checked the coolant when I got home and it's definitely low in the expansion tank, under the minimum.

Seems simple enough to top it up, I'm just slightly confused which coolant to use? The manual says to use G13 and that that's what it comes with from the factory, however it also says that it is purple and the coolant in my tank seems to be more red, which I believe is G12? It says it doesn't reccommend to mix them so just wondering if someone experienced can tell me which one to use? The coolant tank itself also says G13 on it.

Here's what's in the tank currently

1723154059120.png


So it seems to be G12? But the manual and tank say G13 and not to mix them (but people online say you can mix them?). When I search on amazon using my car reg it brings up G40 and G13, when I search on halfords it brings up G40, when I search on autodoc it brings up red G12.

Should I get red G12? Does it matter that much for a smallish top up? My friend also mentioned Prestone which claims to be compatible with any/all other coolants and makes/models etc, is that decent?
 
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SRGTD

Active Member
May 26, 2014
2,510
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I own a VW and when I was last in the local dealers, there was a customer wanting to buy some coolant for topping up and wanted to ensure they bought the correct version. I heard the guy from the parts department saying that VW only have one type of coolant now (sorry, can’t remember what type it was!) and as VW and Seat share the same parts / use the same fluids that’s probably the case for Seat too, so might be worth popping into the parts department at your local Seat dealer to buy a top up bottle.

However, the bigger concern for me would be why your coolant level has dropped below the minimum level as your car shouldn’t be using / losing coolant. Has the drop in coolant level been gradual or has it happened suddenly? Has your cooling system recently been drained and refilled? If so, then it’s possible that if there was any air trapped in the cooling system that wasn’t expelled when the cooling system was refilled, it’s self-purged and caused the coolant level in the expansion tank to fall. Another possible (fairly common) cause of of coolant loss in cars with VAG’s 2.0 EA888 engine is failure of the water pump and thermostat housing, so it would be worth checking that they’re not leaking.
 

QTom

Active Member
Sep 22, 2017
77
16
I own a VW and when I was last in the local dealers, there was a customer wanting to buy some coolant for topping up and wanted to ensure they bought the correct version. I heard the guy from the parts department saying that VW only have one type of coolant now (sorry, can’t remember what type it was!) and as VW and Seat share the same parts / use the same fluids that’s probably the case for Seat too, so might be worth popping into the parts department at your local Seat dealer to buy a top up bottle.

However, the bigger concern for me would be why your coolant level has dropped below the minimum level as your car shouldn’t be using / losing coolant. Has the drop in coolant level been gradual or has it happened suddenly? Has your cooling system recently been drained and refilled? If so, then it’s possible that if there was any air trapped in the cooling system that wasn’t expelled when the cooling system was refilled, it’s self-purged and caused the coolant level in the expansion tank to fall. Another possible (fairly common) cause of of coolant loss in cars with VAG’s 2.0 EA888 engine is failure of the water pump and thermostat housing, so it would be worth checking that they’re not leaking.
I was actually told at my service last year that they saw some coolant stains on the thermostat housing and said it must be leaking, they offered to replace it for £1500 and I said no thanks. Now over a year later it's finally dropped enough to trigger the warning.

Good to know they weren't lying but tbh I'll probably just spend £6 on topping up the coolant once a year rather than £1500 fixing what must be an incredibly slow leak.

I've ordered this to top it up: https://www.amazon.co.uk/gp/product/B0CKFD8JC8

Will get the car serviced soon so I'll mention it to them and maybe just have them drain/refill the system properly.
 

R3k1355

Active Member
Oct 30, 2014
1,809
257
Yorkshire
Blue G11 can't mix with red G12, that's the big one to avoid. You don't see much G12 around anyway, it's moved on to G12+, G12++, G13 etc.

G12 and G12+, G12++, G113 etc, are ok to mix
 
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Had a warning light come on yesterday, I believe it said "Check coolant! User manual!"

I checked the coolant when I got home and it's definitely low in the expansion tank, under the minimum.

Seems simple enough to top it up, I'm just slightly confused which coolant to use? The manual says to use G13 and that that's what it comes with from the factory, however it also says that it is purple and the coolant in my tank seems to be more red, which I believe is G12? It says it doesn't reccommend to mix them so just wondering if someone experienced can tell me which one to use? The coolant tank itself also says G13 on it.

Here's what's in the tank currently

View attachment 43559

So it seems to be G12? But the manual and tank say G13 and not to mix them (but people online say you can mix them?). When I search on amazon using my car reg it brings up G40 and G13, when I search on halfords it brings up G40, when I search on autodoc it brings up red G12.

Should I get red G12? Does it matter that much for a smallish top up? My friend also mentioned Prestone which claims to be compatible with any/all other coolants and makes/models etc, is that decent?


Your car will have left the factory with G13. G12evo is the modern equivalent. The two can be mixed

If you're removing the silica bag, ensure you only use G12evo in future.
 
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RUM4MO

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Jun 4, 2008
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South Scotland
It's good to see that someone other than VW Group is now supplying G12evo into the aftermarket in UK.

I bought a couple of 1 litre bottles of G12evo to add to my stock of G12evo left over from replacing the G12+ or G12++ in my 2011 S4 a couple of years ago, so now to eventually do what I keep saying I'm going to do - and that is to get rid of the time expired G13 from my wife's August 2015 VW Polo 1.2TSI as it does not have a Silicate granule pouch/teabag not even from factory as probably it was not deemed necessary for this engine, but on checking the ph of the coolant, it is well on its way towards being acidic, so time to replace it!
By the way, a 1 litre bottle of genuine G12evo currently retails for £8.40 inc VAT from any VW Group dealership's parts department.
 
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Walone

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Feb 10, 2016
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Near Heathrow
It's good to see that someone other than VW Group is now supplying G12evo into the aftermarket in UK.

I bought a couple of 1 litre bottles of G12evo to add to my stock of G12evo left over from replacing the G12+ or G12++ in my 2011 S4 a couple of years ago, so now to eventually do what I keep saying I'm going to do - and that is to get rid of the time expired G13 from my wife's August 2015 VW Polo 1.2TSI as it does not have a Silicate granule pouch/teabag not even from factory as probably it was not deemed necessary for this engine, but on checking the ph of the coolant, it is well on its way towards being acidic, so time to replace it!
By the way, a 1 litre bottle of genuine G12evo currently retails for £8.40 inc VAT from any VW Group dealership's parts department.
Just seen that 5 litres of Holts G12evo (ready mixed) is less than £18! Is the geniune VW stuff also ready mixed? Also what do you use to test the ph? :)
 

RUM4MO

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Jun 4, 2008
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Yes, typically the VW Group coolant is pre mixed 50/50.

I bought via ebay - from USA a tube of "coolant test strips" trade name "COOLTRAK" they are double ended with ph test strips at one end and %age coolant on the other end.

I'm not really bothered about the %age or freezing point as I have a optical "thing" for checking that, ie refractometer.

The bottom line is, they are sold in too high volume package, so they last much longer than their indicated shelf life is - unless you have a garage/workshop!

They are not perfect for use with a coolant that has a colouring dye in it, but works okay, even although my pack is maybe 6 years old, I still check the "quality" of these strips using new still in bottle coolant - for reference.

If someone was smart enough to price them low enough and repackage them in maybe 4's or 5's, then maybe they would sell in numbers to anyone concerned enough about this possible issue.

I've forgotten what prompted me to find the need to buy them, but having them has allowed me to test the coolant on all 3 of our cars, or maybe even 4, annually and that showed me how quickly G13 reduces in corrosion prevention over time, if used in a car that does not have "mit silikat" granules to top it back up! It also helped me make the decision to replace the G12+/G12++ in my 2011 S4 seeing as it has a timing chain and robust water pump, so no obvious reason to need to open up the coolant system and so replace the coolant.

One other thing, after buying that refractometer, I started using it on my washer fluid, both any premixed volumes kept in a "sealed" container, and concentrated washer fluid additive - and was shocked to see how high the freezing point was on some older mixed quantities, luckily I managed to use more older premixed fluid in summer really just to get it used up before winter, before running into any problems. So ow the plan is to only premix as much as I can use in a couple of months, lesson learned, I had been living in a fool paradise!
 
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Walone

Active Member
Feb 10, 2016
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Near Heathrow
Yes, typically the VW Group coolant is pre mixed 50/50.

I bought via ebay - from USA a tube of "coolant test strips" trade name "COOLTRAK" they are double ended with ph test strips at one end and %age coolant on the other end.

I'm not really bothered about the %age or freezing point as I have a optical "thing" for checking that, ie refractometer.

The bottom line is, they are sold in too high volume package, so they last much longer than their indicated shelf life is - unless you have a garage/workshop!

They are not perfect for use with a coolant that has a colouring dye in it, but works okay, even although my pack is maybe 6 years old, I still check the "quality" of these strips using new still in bottle coolant - for reference.

If someone was smart enough to price them low enough and repackage them in maybe 4's or 5's, then maybe they would sell in numbers to anyone concerned enough about this possible issue.

I've forgotten what prompted me to find the need to buy them, but having them has allowed me to test the coolant on all 3 of our cars, or maybe even 4, annually and that showed me how quickly G13 reduces in corrosion prevention over time, if used in a car that does not have "mit silikat" granules to top it back up! It also helped me make the decision to replace the G12+/G12++ in my 2011 S4 seeing as it has a timing chain and robust water pump, so no obvious reason to need to open up the coolant system and so replace the coolant.

One other thing, after buying that refractometer, I started using it on my washer fluid, both any premixed volumes kept in a "sealed" container, and concentrated washer fluid additive - and was shocked to see how high the freezing point was on some older mixed quantities, luckily I managed to use more older premixed fluid in summer really just to get it used up before winter, before running into any problems. So ow the plan is to only premix as much as I can use in a couple of months, lesson learned, I had been living in a fool paradise!
Thanks for the reply @RUM4MO :) (y)
 

RUM4MO

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Jun 4, 2008
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South Scotland
Finally, just to add insult to the VW Group pricing, a couple or so years back, that coolant was only ever sold in 1ltr containers and maybe 50ltr container - or maybe it was even 100ltr drums, so for the DIYer it had to be buying it by the 1ltr bottles!

There was someone online, maybe Coxs selling it in 5ltr containers, but the mix was only 40/60 and as VW Group only ever used 50/50 at factory, I gave that option a miss, curiously (or not), when checking up on an online VW Group parts listing site, there never was an option to buy a 40/60 mix - which seemed strange and so why/how could a SEAT dealership be selling that, there was even pictures of the container which did indicate that it was a 40/60 mix - as the 40/60 and 50/50 premix coolant have different part numbers. Nowadays, when/where ever it is getting sold online in 5ltr containers, it is only available in 50/50 premix.
 

QTom

Active Member
Sep 22, 2017
77
16
OK so I've made a right mess of everything now. I topped up the coolant and unfortunately it lost it again so there is clearly a leak. I've booked it in for a service and for them to take a look at the leak, that's on Thursday.

But this evening I had to go somewhere, so I topped it up with the last of the coolant I had as it was a little low again, drove to the place, it seemed OK but right as I parked the coolant warning came on again. I get out the car and can see a significant amount of coolant has dripped out as I parked. I go to check the expansion tank and... I forgot to put the ******* cap back on when I topped it up. So I drove about 10 minutes without it on, so obviously I lost a lot of coolant. The temperature gauge in the car was normal the whole way so hopefully I didn't do any damage but I feel like an absolute idiot.

Obviously I didn't want to drive it any more after losing a lot of coolant so my friend gave me a lift to Morrisons and I bought some of the prestone stuff as it's the best I could get and topped up with that before driving home. Again the temperature seemed fine on the 10 min drive home but now I have a mix of G13 and this prestone stuff (which I think is OK, at least short term?), so I guess I will have to ensure the garage flushes the coolant and puts the right stuff in again now.

Can't believe I made such a dumb mistake. Fear this will be an expensive visit to the dealer :confused:
 

RUM4MO

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Jun 4, 2008
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South Scotland
Accidents do/can happen, my older daughter's partner took his "garage queen" Lotus Esprit GT S3 into the local Lotus indie specialist for an MOT and a check over the other week.
He collected it in stop go rush hour traffic time and drove the few miles home - but for the last mile or so white smoke was "gushing" out of the engine air side pods - not good when unable to get out of the traffic!
When he got home he discovered that the oil filler can was not fitted to the engine - in was lying in the "boot" area - f--ng idiot experts can also make mistakes.
 

QTom

Active Member
Sep 22, 2017
77
16
Haha, that makes me feel a bit better thanks.

Does anyone know if I need to worry about the Prestone mixed with the G13 (or whatever is already in there, tbh I have no idea, I topped it up with this: https://www.amazon.co.uk/gp/product/B0CKFD8JC8 before)?

Either way I'll ask the garage to flush it and put the correct stuff in I guess, though I'd assume that is done anyway if the thermostat housing/water pump has to be replaced?

Not sure if I should just put the rest of the Prestone I bought in there or order another bottle of that G13 stuff and use that so it is at least mostly right?
 

RUM4MO

Active Member
Jun 4, 2008
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South Scotland
That listing does claim that it is compatible with VW Group coolants so not worth bothering to worry about it.

Edit:- you should be aiming to get VW Group G12evo or an equivalent loaded into your car after it has been repaired, G13 is from yesterday and is now not the best coolant to have in a car.
 

Mo_86

Active Member
Sep 25, 2023
175
48
UK
That listing does claim that it is compatible with VW Group coolants so not worth bothering to worry about it.

Edit:- you should be aiming to get VW Group G12evo or an equivalent loaded into your car after it has been repaired, G13 is from yesterday and is now not the best coolant to have in a car.
Any links for alternative to vw?
 

RUM4MO

Active Member
Jun 4, 2008
7,929
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South Scotland
Proper equivalent to VW Group G12evo do now exist in UK, but I tend to make the effort to buy genuine VW Group G12evo, genuine G12evo coolant should/could last 8 > 10 years so which risk buying something that is slightly cheaper and claims it needs replaced after maybe 3 years.
 

MartinThorn

Active Member
Feb 28, 2024
52
16
Filled my car with this G12EVO stuff from eurocarparts recently - ok so far. Also comes in a 1L bottle.

 
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