Removing silica bag from coolant header tank

SuperV8

Active Member
May 30, 2019
1,546
686
As these silica bags serve an important purpose, is it not possible to just periodically replace it with a new one? That's if they're available to buy. I'm assuming they split due to age from going through 1000's of heat cycles which deteriorates the plastic.
The latest tanks are without silicate from VAG. They just use a different coolant.
 
  • Like
Reactions: SteveGSXR600K1

SRGTD

Active Member
May 26, 2014
2,562
1,408
This is the 'double skinned' version I had in my 2015 184TDI - no removable 'Tea Bag'
You cannot remove this type of silicate repository without destroying the tank.
I have my doubts whether this type can actually leak? and if it did the coolant return flow would have to be strong/fast enough to carry the granules up and over the container which again I doubt as there isn't much flow through the coolant header tank return pipe.
I changed mine anyway to a tank without Mit'Silicate. 'just in case!'
View attachment 34044

There was a forum member over on briskoda.net forum who butchered their double skinned expansion tank to get to the silicate bag - picture from post on page8 of the discussion thread at the link below;


28BAD21B-BB69-4C82-B908-2C6886A7AE7A.jpeg
 

LeylandVCDS

Active Member
Apr 20, 2015
417
243
Leyland, Lancashire
This is the 'double skinned' version I had in my 2015 184TDI - no removable 'Tea Bag'
You cannot remove this type of silicate repository without destroying the tank.
I have my doubts whether this type can actually leak? and if it did the coolant return flow would have to be strong/fast enough to carry the granules up and over the container which again I doubt as there isn't much flow through the coolant header tank return pipe.
I changed mine anyway to a tank without Mit'Silicate. 'just in case!'
View attachment 34044
The pressure in the system would surely allow flow of the granules, they won't be that heavy. If the design is as in the diagram, why on earth have they not built in filters to stop the granules moving away from where the bag is situated?
As these silica bags serve an important purpose,
But do they?
 

RUM4MO

Active Member
Jun 4, 2008
7,970
1,060
South Scotland
The pressure in the system would surely allow flow of the granules, they won't be that heavy. If the design is as in the diagram, why on earth have they not built in filters to stop the granules moving away from where the bag is situated?

But do they?
I can't see them bothering to fit these silicate pouches if they were not needed, mainly, it seems, with TDI engines, as I've said many times, "is this only a G13 coolant issue?|" and if so, changing to G12evo should let you walk away from it.
 

SuperV8

Active Member
May 30, 2019
1,546
686
The pressure in the system would surely allow flow of the granules, they won't be that heavy. If the design is as in the diagram, why on earth have they not built in filters to stop the granules moving away from where the bag is situated?

But do they?
Cooling systems aren't designed with much flow through the expansion tank. The expansion tank is only there to collect air and allow expansion of the coolant is it gets hot.
 

Rob McCool

Active Member
Sep 15, 2009
71
13
Birkenhead
This is the 'double skinned' version I had in my 2015 184TDI - no removable 'Tea Bag'
You cannot remove this type of silicate repository without destroying the tank.
I have my doubts whether this type can actually leak? and if it did the coolant return flow would have to be strong/fast enough to carry the granules up and over the container which again I doubt as there isn't much flow through the coolant header tank return pipe.
I changed mine anyway to a tank without Mit'Silicate. 'just in case!'
View attachment 34044
I had this tank version on my 2013 Leon FR184 and had the losing coolant problem .Brian Gordon-Stables gave me some very helpful advice on how to change the matrix and expansion tank.I did this about a month ago and so far,so good.
 

mykro

Active Member
Apr 12, 2022
73
7
I had this tank version on my 2013 Leon FR184 and had the losing coolant problem .Brian Gordon-Stables gave me some very helpful advice on how to change the matrix and expansion tank.I did this about a month ago and so far,so good.
and where this coolant goes? onto carpet in interrior or where it leaks ?
 

csd_19

Full Member
May 11, 2005
2,279
28
Angus / Edinburgh
Looks like it's Feb 2020 when the latest bottle revision was brought in (M).

I thought I'd be lucky in my 18-plater (before doing some research) but no, it's the "mit silikat" version and to add insult to injury it's the double walled 'G' revision. Looks like I'll be ordering an 'M' version now (5Q0 121 407 M).

IN fact, I might order two as I'll need to have a look at my folks' 2018 Ateca 2.0TSI as well...
 

RUM4MO

Active Member
Jun 4, 2008
7,970
1,060
South Scotland
Looks like it's Feb 2020 when the latest bottle revision was brought in (M).

I thought I'd be lucky in my 18-plater (before doing some research) but no, it's the "mit silikat" version and to add insult to injury it's the double walled 'G' revision. Looks like I'll be ordering an 'M' version now (5Q0 121 407 M).

IN fact, I might order two as I'll need to have a look at my folks' 2018 Ateca 2.0TSI as well...
Are you going to replace the G13 with G12evo when you replace the reservoir bottle?

I was servicing the brakes, including replacing the rear pads on my daughter's May 2019 Leon Cupra, I meant to check the coolant with some "test strips" that I have, really just to make sure that the PH level was still okay as it should be as it has one of these silicate loaded reservoirs, but I forgot to bring the test strips out with me to the garage, and her time was tight, so I just topped up the coolant with neat G13, I should try to convince her to change to that non silicate reservoir and change to G12evo in the spring time, I'll use your info on which version meets that criteria, if or when she agrees that doing that is a good enough plan!
 
  • Like
Reactions: csd_19

csd_19

Full Member
May 11, 2005
2,279
28
Angus / Edinburgh
Are you going to replace the G13 with G12evo when you replace the reservoir bottle?

I was servicing the brakes, including replacing the rear pads on my daughter's May 2019 Leon Cupra, I meant to check the coolant with some "test strips" that I have, really just to make sure that the PH level was still okay as it should be as it has one of these silicate loaded reservoirs, but I forgot to bring the test strips out with me to the garage, and her time was tight, so I just topped up the coolant with neat G13, I should try to convince her to change to that non silicate reservoir and change to G12evo in the spring time, I'll use your info on which version meets that criteria, if or when she agrees that doing that is a good enough plan!

For the moment I'm just going to top up the new reservoir with 50/50 G13/water and do the change to G12evo early next year.
 
  • Like
Reactions: RUM4MO
Nov 11, 2022
2
1
I have an Audi A3 2014. My heating stopped working a couple of weeks ago, took it straight to the garage and they gave me the news that this bag had split and I have had to have my water pump & timing belt replaced, my heating matrix, multiple pipes and both the radiators in the car... should be collecting my car today and paying a £2000 bill. I am just so worried now that other damage could have been caused? does anyone know? Also, its all bee flushed out, but am I to expect to have to more issues would you say? I have raised this with Audi and I am waiting for someone to come back to me, I probably wont get anywhere... but what an absolutely stupid thing to put in a car knowing this is happening.
 

RUM4MO

Active Member
Jun 4, 2008
7,970
1,060
South Scotland
I think that there is an official recovery procedure that some be carried out after this has happened, it will involve flushing sections of the system before fitting the new heater matrix - I would hope, as flushing sections out while the blocked heater matrix is in place is stupid, as is flushing that section after fitting the new heater matrix. Unfortunately, you do need trust that dealer's workshop, this type of failure is a license to print money.
Maybe I should do the "good father" bit even more and grab one of these non silicate reservoirs for my daughter's Leon Cupra.

Just one last thing, is your Audi A3 a Deisel or Petrol model?
 

RUM4MO

Active Member
Jun 4, 2008
7,970
1,060
South Scotland
There was a forum member over on briskoda.net forum who butchered their double skinned expansion tank to get to the silicate bag - picture from post on page8 of the discussion thread at the link below;


View attachment 34045
I'll admit to being naive enough to have assumed that all reservoirs that had that material within the double skin, would have a properly engineered way to package it - I was wrong!
 
Nov 11, 2022
2
1
I think that there is an official recovery procedure that some be carried out after this has happened, it will involve flushing sections of the system before fitting the new heater matrix - I would hope, as flushing sections out while the blocked heater matrix is in place is stupid, as is flushing that section after fitting the new heater matrix. Unfortunately, you do need trust that dealer's workshop, this type of failure is a license to print money.
Maybe I should do the "good father" bit even more and grab one of these non silicate reservoirs for my daughter's Leon Cupra.

Just one last thing, is your Audi A3 a Deisel or Petrol model?
Mine is a 1.9 diesel. My header tank says Mit Silikat on it. The garage did flush it all out and replaced some pipes that were clogged too. I spammed Audi on social too, and now they are "looking in to it" I feel traumatised by this whole avoidable experience!
 
  • Like
Reactions: RUM4MO

Lord_Nikkon

Active Member
Jul 18, 2020
51
13
Poland
I changed my "mit silkat" tank for newer one without this crap and change "eco" coolant to normal one. Everything in dealer garage. No issue.
 
Lecatona HPFP (High-pressure Fuel Pump Upgrades)