silica grain in the header tank

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I am seeing a lot of comments on VW / Audi and Leon sites about heating matrix needing sorting.

I personally have so far had no issues with this at all but I also see a lot of people commenting on removing the Silica grain bag in the header tank.

Anybody got any information.

TIA.
 

zedlor

Active Member
Aug 24, 2017
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Warrington
It's all incredibly overblown to me. Somebody's seen a couple of people needing new heater matrixes because their bags have exploded, but it's very rare. So now everyone is taking theirs out, without any kind of knowledge as to what it's doing. I saw a whole comment chain on Facebook where people were saying it's pointless because it's a sealed bag...well, no, it's not sealed, it's breathable and provides extra silicon to the coolant which VW obviously think is required.

Unfortunately I don't have one in mine so I can't take it out and plaster it all over Facebook.
 
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Deleted member 103408

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Which is why I raised the question so we can get a more informed view on the issue.

However i have seen on this site more than a few people with issues on the heating matrix just not noticed the silicone being identified as the problem.

Going to have to look in my tank now to see if I have one even.

Thanks.
 

MGH74

Active Member
Dec 17, 2017
47
4
I had mine go.
Went in for thermostat housing as the constant leak was annoying, then whilst there it had to have water pump replaced as well, then a new tank and heater matrix as the heating stopped a few days later.
No explanations, just a bill.
 

Walone

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Feb 10, 2016
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I am seeing a lot of comments on VW / Audi and Leon sites about heating matrix needing sorting.

I personally have so far had no issues with this at all but I also see a lot of people commenting on removing the Silica grain bag in the header tank.

Anybody got any information.

TIA.
A lot of the expansion tanks don't have it, mine doesn't (1.4/150 ACT), I wonder why VAG put it in some vehicles and not others?
The ones with it in have a sign on the tank near the G13 symbol saying 'Mit Silikat'.
 

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And I saw a comment yesterday saying it happens more on Diesels that on Petrol cars.
 

JayClarke

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Apr 18, 2018
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From what I've been told by CLP, it's used as a corrosion inhibitor and from the sounds of it, the issue has been blown way out of proportion.

If you remove it, you'll likely have to replace the coolant more regular.

I'll personally be leaving mine in, it's there for a reason and I'd rather listen to a professional over 'Jeff' from a Facebook group
 
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Deleted member 103408

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Hence the point of this thread, is it hype or fact, so far its hype

However the so called professionals also can be muppets just like the rest of us especially when you ask about servicing the DSG Box and Front Diff.
 

TheSwede

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Oct 20, 2018
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I don't know if I have a silica bag in our Cupra or Golf AllTrack, both cars from -18 and with EA888 engine, haven't opened the cap yet. If the bag is there I will leave it as it is.

G13 coolant, no need to change (there are no time/distance intervals). On our old A4 convertible G12 coolant was changed at the same time as change of water pump / cam belt.

/Peter
 

Walone

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Feb 10, 2016
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I don't know if I have a silica bag in our Cupra or Golf AllTrack, both cars from -18 and with EA888 engine, haven't opened the cap yet. If the bag is there I will leave it as it is.

G13 coolant, no need to change (there are no time/distance intervals). On our old A4 convertible G12 coolant was changed at the same time as change of water pump / cam belt.

/Peter
The ones with it in have a sign on the tank near the G13 and refer to handbook symbols saying 'Mit Silikat', if it doesn't say 'Mit Silikat' then there is no bag in the expansion tank.
 

TheSwede

Active Member
Oct 20, 2018
306
167
Sweden
The ones with it in have a sign on the tank near the G13 and refer to handbook symbols saying 'Mit Silikat', if it doesn't say 'Mit Silikat' then there is no bag in the expansion tank.

Did a check - Both the Cupra and Golf have a bag.

Edit Think my former Golf R 2014 also had it (from an old pick of engine bay, the text is there).
 
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zedlor

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Aug 24, 2017
298
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Warrington
Merc use them as well.

I wonder if some engines have some different material somewhere along the way that needs silica reinforcement?
 

Deleted member 103408

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Just found this

From one of VW's Self Study Program 514 page 31:

Coolant Expansion Tank with Silicate Repository

The coolant expansion tank contains a silicate repository. Silicate is used to protect the aluminum components in the coolant
system from corrosion. There are silicates in the G13 coolant, but they are used up over time if the engine is subject to high
thermal loads.

To compensate for the silicate consumption, silicate is taken from the repository and added to the coolant. The silicate
repository provides additional protection against corrosion for the aluminum components in the coolant system over the entire
lifespan of the engine.
 

Seastormer

Cupra Leon VZ2 300/CBF1000
Apr 25, 2014
5,006
692
68
Edinburgh (Scotland)
I have just checked my car, and the expansion tank has the 'Mit Silikat' on it but no silcate bag in the tank. Is this marking not just there to warn that the coolant is not the old OAT based stuff (G10, G11) and needs silcate based type (G12, G12++, G13) Otherwise why do I have no bag, maybe only certain models had it in, there is mention of it in the cars handbook or warning about not having it.
 

RUM4MO

Active Member
Jun 4, 2008
7,784
983
South Scotland
I've just discovered that my daughter's May 2019 Leon Cupra has "Mit Silikat" printed onto its engine coolant reservoir - and there is a bag/sack of silicate in the reservoir!

So, does anyone know if VW Group ever intend to "update" their engine coolant additive so that these cars no longer need these bag/sacks fitted into the reservoir, or does this fly in the face of SEAT generating more income when these bags/sacks split open and their contents ends up blocking the water flow through the cabin heater matrix?
 

Norbert

Active Member
Oct 16, 2018
395
98
I've just discovered that my daughter's May 2019 Leon Cupra has "Mit Silikat" printed onto its engine coolant reservoir - and there is a bag/sack of silicate in the reservoir!

So, does anyone know if VW Group ever intend to "update" their engine coolant additive so that these cars no longer need these bag/sacks fitted into the reservoir, or does this fly in the face of SEAT generating more income when these bags/sacks split open and their contents ends up blocking the water flow through the cabin heater matrix?
I just checked mine and no silikat.
However just checked oil and look badly over filled car done 180miles.
 

Norbert

Active Member
Oct 16, 2018
395
98
Brand new car i picked up yesterday with 10 miles in but was visible oil drip around stick so they messed with it. Seriously i just opened the bonnet as your writing.
 

RUM4MO

Active Member
Jun 4, 2008
7,784
983
South Scotland
Sorry for me doing that, at least it is the right colour, what is your plan, suck some oil out (if you have the kit), of just drop some out the sump drain plug?
 

Norbert

Active Member
Oct 16, 2018
395
98
No i need to thank you before cause long term damage.
I got sucking kit as i have a smart car too and smart with out drain plug.removed some oil, around full now i will check tomorrow.
 
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