Removing silica bag from coolant header tank

RUM4MO

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Jun 4, 2008
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South Scotland
A sharpie ? 😂
Oh yes, but I was thinking about something a bit more "factory" - so far I've resisted using a Sharpie on my 2011 Audi S4 that I changed to G12evo maybe 2 years ago, it kind of annoys me that the reservoir "coolant description" is now not correct! Maybe I need to see if my older daughter's partner still has a label printer that would solve that on our car(s) and that daughter's Cupra after I've extracted cash from her to buy a new reservoir and G12evo - a job for the warmer weather though!
 

LeylandVCDS

Active Member
Apr 20, 2015
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Leyland, Lancashire
The new bottle I fitted to my Leon this last weekend (this one) does not have any coolant type label
 

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SuperV8

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May 30, 2019
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Oh yes, but I was thinking about something a bit more "factory" - so far I've resisted using a Sharpie on my 2011 Audi S4 that I changed to G12evo maybe 2 years ago, it kind of annoys me that the reservoir "coolant description" is now not correct! Maybe I need to see if my older daughter's partner still has a label printer that would solve that on our car(s) and that daughter's Cupra after I've extracted cash from her to buy a new reservoir and G12evo - a job for the warmer weather though!
I can see a supersession from:
5Q0121407G to 5Q0121407M removing mit silikat and blacking out the G13! from July 2019 Leon's should have the latest 5Q0121407M tank - presume this is also with a switch in coolant type.

edit:
Yes same date for a change in coolant G013A8J M1 to G12E100M2. (G13 to G12evo)

5Q0121407G
1701160940530.png


5Q0121407M
1701160961197.png

1701161144600.png
 
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Bluepower

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May 1, 2016
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I actually replaced my coolant tank a few weeks ago. Mainly because it is already almost 10 years old, so could potentially be a part that could start leaking any moment, and also because of the silikat bag in there, that is also over 9 years old.
I replaced it with a new bottle with silikat, I guess that in 5-7 years I (if I still own this car) will replace it again, just for the sake of mind and I highly doubt the bag will rupture within that time span?
 

jr795

Active Member
Dec 28, 2023
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Hi folks. I am looking at buying a Cupra 300 (so either a 2017 or 2018). Would this have the double skinned tank? (thus requiring me to change it for the M revision without silica).

Is the switch to G12 evo required if getting rid of the silica or just recommended?

Do you think a main dealer would change the tank/coolant or would it have to be an indy? I am wanting an approved used car as they have a better chance of not being modified but I don't want to void the two year manufacturer warranty those come with (ideally I would get the dealer I buy from to do it for me before I take delivery). I suppose you could argue that VAG obviously realised it's a daft idea as they abandoned it themselves around 2019.

Thanks!
 
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RUM4MO

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Jun 4, 2008
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Personally I do consider that if you remove the silicate pouch and leave the coolant as being G13, then its ph value will move quickly towards being acidic. I've noticed that this happened with my wife's 2015 VW Polo 1.2TSI 110PS and they came from the factory with G13 and no silicate pouches, I think that the higher temperature encountered with certain engine types/codes made this happen quicker than with others - so maybe that was why this 2015 VW Polo 1.2TSI 110PS came without a silicate pouch - or VW Group were just beginning to get an understanding of the limitations of G13 in certain engine types/codes.

I do plan to replace the G13 in my wife's 2015 VW Polo 1.2TSI 110PS with G12evo next year.

Edit:- just one other comment, it could be that your SEAT dealership selling any approved cars, will take the line "don't worry the warranty will cover you against any problems" and go on to explain that all this talk about G13 needing replaced is just internet waffle - exactly the same as needing to replace Haldex fluid - as (they know) all Haldex systems are sealed.
Off Topic warning - I was in my local Audi dealership getting parts last week, and while collecting my new very expensive engine mountings, asked the price of the fill and drain plugs for the Haldex coupling on the front diff of 2WD Leon Cupras - all I got was, "well seeing as the Haldex fluid is over £40 a container, you can see that it is intended to be in there for life, so we never sell any fill/drain plugs" - possibly my error asking that question as I'd doubt if any 2WD Audis have a higher output engine that needs that VAQ at the front - but puts in a bit of doubt if any Audis passing through their workshop is getting the Haldex serviced!
 
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LeylandVCDS

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Apr 20, 2015
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Hi folks. I am looking at buying a Cupra 300 (so either a 2017 or 2018). Would this have the double skinned tank? (thus requiring me to change it for the M revision without silica).

Is the switch to G12 evo required if getting rid of the silica or just recommended?

Do you think a main dealer would change the tank/coolant or would it have to be an indy? I am wanting an approved used car as they have a better chance of not being modified but I don't want to void the two year manufacturer warranty those come with (ideally I would get the dealer I buy from to do it for me before I take delivery). I suppose you could argue that VAG obviously realised it's a daft idea as they abandoned it themselves around 2019.

Thanks!
I changed my bottle to get rid of the silica bag a few weeks ago. but left the coolant as it was for the time being - but it will be having a full coolant change in the spring when the cambelt and water pump are changed. It will then be getting the G12 evo put in.
Personally I'm not sure a dealer will change the bottle, as it would be taking the car away from original factory spec., though this isn't necessarily the case - for example, the recognised rectification of a failed dual mass flywheel on the old 1.9PD Octavias was to do a solid flywheel conversion (which I had done myself, with great success). No issues with an independant doing it though
 
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jr795

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Dec 28, 2023
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I changed my bottle to get rid of the silica bag a few weeks ago. but left the coolant as it was for the time being - but it will be having a full coolant change in the spring when the cambelt and water pump are changed. It will then be getting the G12 evo put in.
Personally I'm not sure a dealer will change the bottle, as it would be taking the car away from original factory spec., though this isn't necessarily the case - for example, the recognised rectification of a failed dual mass flywheel on the old 1.9PD Octavias was to do a solid flywheel conversion (which I had done myself, with great success). No issues with an independant doing it though
Thanks, yeah that makes sense. I could try and talk my way into it by arguing that a 2019 model mk3 Leon would have the non silicate header tank and g12 evo in it so it's not like it's a massive deviation from factory. I think I'm right in saying that if a dealer were to replace the header tank due to failure/change the coolant then they'd be using the silicate free tank and g12 evo anyway?

I suppose with the approved used 2 year warranty I could just drive it for the two years. If it fails then they'll have to do it under warranty anyway, if it doesn't then I can just wait until the warranty expires and get an indy to do it. Just seems daft to knowingly await this issue and then they have to replace the matrix/flush the system however many times when it can be easily avoided using upgraded factory parts from a slightly later car. Plus a tad inconvenient if it does happen
 

LeylandVCDS

Active Member
Apr 20, 2015
416
242
Leyland, Lancashire
Thanks, yeah that makes sense. I could try and talk my way into it by arguing that a 2019 model mk3 Leon would have the non silicate header tank and g12 evo in it so it's not like it's a massive deviation from factory. I think I'm right in saying that if a dealer were to replace the header tank due to failure/change the coolant then they'd be using the silicate free tank and g12 evo anyway?

I suppose with the approved used 2 year warranty I could just drive it for the two years. If it fails then they'll have to do it under warranty anyway, if it doesn't then I can just wait until the warranty expires and get an indy to do it. Just seems daft to knowingly await this issue and then they have to replace the matrix/flush the system however many times when it can be easily avoided using upgraded factory parts from a slightly later car. Plus a tad inconvenient if it does happen
Well, the coolant bottle WITH silicate bag is still listed as an option on the parts catalogue ETKA, as are bottles WITHOUT.......Read into that what you will, but it certainly didn't influence me changing the bottle on my 2019 2.0TDI to get rid of the silicate bag. There is an ebay link in my post above for the one I bought... reliable enough seller, it arrived within three days of ordering. It literally is a 10 minute job to change too, and the way I look at it, it's a far safer option than a silicate bag bursting
 
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jr795

Active Member
Dec 28, 2023
28
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@jr795 - other option is this -- change the bottle, say nothing, and if anything is said, you know nothing about the change as it was done by the previous owner, and it is how you bought the car
Yeah that's not a bad idea. It had occurred to me that I might get lucky and find that the previous owner has already carried this job out for me (more likely when you could just take the bag out but I suppose replacing the double walled tank is a bit more involved)
 

Jason2023

Active Member
Jul 13, 2023
46
15
Hi all joining late, so apologies if this has been mentioned or asked (I did read through first). Checked my Leon FR 1.4 TSI ACT it has the bottle referencing the G13 Top up logo but no reference to the mit silikat, had a quick look inside couldn’t see anything! Is it obvious if the bag is in there? Also can a tank reference G13 with no bag?
 

jr795

Active Member
Dec 28, 2023
28
9
Hi all joining late, so apologies if this has been mentioned or asked (I did read through first). Checked my Leon FR 1.4 TSI ACT it has the bottle referencing the G13 Top up logo but no reference to the mit silikat, had a quick look inside couldn’t see anything! Is it obvious if the bag is in there? Also can a tank reference G13 with no bag?
I had my brother check his 2016 Polo BlueGT (1.4 TSI ACT) yesterday after I found out about this. His tank also says G13 but no mit silikat. I think on the smaller capacity engines VAG didn't feel the need to bother with it
 
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SRGTD

Active Member
May 26, 2014
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I had my brother check his 2016 Polo BlueGT (1.4 TSI ACT) yesterday after I found out about this. His tank also says G13 but no mit silikat. I think on the smaller capacity engines VAG didn't feel the need to bother with it
I didn’t have one of the silicate bags in the coolant expansion tank in my previous 2016 Polo GTI either. That car had a 1.8 litre TSI 192ps engine.
 
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Mo_86

Active Member
Sep 25, 2023
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UK
Got the dreaded bag in my car, its wedged to one side and is really difficult to get it to the middle to then remove it. Any tips?
 

Jason2023

Active Member
Jul 13, 2023
46
15
I had my brother check his 2016 Polo BlueGT (1.4 TSI ACT) yesterday after I found out about this. His tank also says G13 but no mit silikat. I think on the smaller capacity engines VAG didn't feel the need to bother with it
That’s interesting mine is a 2014 so hopefully all ok….
 
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