7 minutes ago, cheezemonkhai said:

The silica in the bag was clean almost clear in colour,  hence the thoughts on casting sand.

 

 

 well if its in the water ways  it could be in the oilways .....

The stuff in my coolant looked different to that. I'd say that photo does look more like sand (or much as described earlier!). Mine looked like the photo attached.

 

2 hours ago, J_D said:

The stuff in my coolant looked different to that. I'd say that photo does look more like sand (or much as described earlier!). Mine looked like the photo attached.

 

IF YOU MIX IT WITH ENOUGH WATER THOUGH ... ITS A KNOWN VAG FAULT

All I would say is I wouldn't rule out some casting sand and I wouldn't 100% rule out the silica either.

Just seems odd that it's so dark in colour, almost like the clay heavy green casting sands (Not green in colour).

 

Dellbert, could you link me to some material I can read ref the known VAG fault? I can make my own reasoned decision then. :).

Edited 4 December, 20205 yr by J_D
Name correction

Check out the vag forums .

cant see what else it could be after checking the bag flushing and running without it the bag you get that out of it  . Bear in mind it had a matrix water pump back in January and a flush

Had a discusion with the dealer this afternoon , new engine is a possibility if it comes back again .  or a good deal on a px now .....

Being actually able to see the bag or having Mit Silika on the tank, is that the definitive way to know if you have/had the bag?

 

I've a 2017 1.4Tsi, pre facelift, and my tank is 5Q0121407 F, it doesn't have Mit Silika on the tank, just G13, am I safe to assume I'm not at risk of anything a burst bag can bring? 

There does not seem to be a pattern for inclusion of the Silicate bag.  The post below includes comments from @Pagan-Image whose 68 Plate VRS included a Silicate bag, where as my 67 Plate 1.4 SEL does not.

 

 

Edited 6 May, 20215 yr by FrankNicklin

On 06/05/2021 at 13:47, Jip said:

Being actually able to see the bag or having Mit Silika on the tank, is that the definitive way to know if you have/had the bag?

 

I've a 2017 1.4Tsi, pre facelift, and my tank is 5Q0121407 F, it doesn't have Mit Silika on the tank, just G13, am I safe to assume I'm not at risk of anything a burst bag can bring? 

Possibly so, I just changed the expansion bottle on my MY16 Octavia as a precaution - late 2015 model, same part number as yours - I can't see any bag in mine either but a easy job for ease of mind in avoiding an expensive problem.

Edited 15 May, 20215 yr by Warrior193
correction

It's due for a service soon so I'll just ask them to clarify and it'll be on the service notes too at least if it turns out they're wrong.

Edited 15 May, 20215 yr by Jip

ITS NOT ALWAYS THE BAG 

 

Casting sand was not allways fully removed from the block  which vag group are fully aware of but wont admit

On 15/05/2021 at 12:06, Dellbert said:

ITS NOT ALWAYS THE BAG 

 

Casting sand was not allways fully removed from the block  which vag group are fully aware of but wont admit

 

I ordered a replacement bottle from my local Skoda dealer and asked the Parts Guy to check that it didn't have the Bag in it, he asked me if I was worried about it splitting and blocking the system, he knew all about it but he said that the Skoda Mechanics had 3 different theories about how it happens and none of them could agree.

Theory 1 is the Silica Bag Splitting, Theory 2 is that it is sand left over in the system from the casting process and Theory 3 is that if the engine overheats  the coolant boils and it goes gloopy and blocks up the system.

 

He also said that Skoda would never admit to any of these.

 

But for under 40euro for a replacement tank I'll be replacing mine soon (once shops reopen and I can get a turkey baster  ) to eliminate Theory 1 from the equation.

A little difficult to see how casting sand has been left in cooling channels, as some posters have posited, but seemingly no evidence of it in oil ways. I have not seen actual engine-block production, but I'd guess the bare block goes through thorough cleansing process involving all passages.

On another note, the appearance of the residue that has been the cause of heating matrix's may possibly be a little misleading - I once had a diesel contamination (diesel bug) issue in my boats fuel system - the stuff clogging the primary and secondary filters was black and gritty, and looked (and felt) for all the world like sand! It was actually dead and dying bacteria.  

Hi guys,

 

After reading this thread I decided to check the expansion tank on my 2016 Mk7 GTI PP and sure enough I've the Mit Silikat revision G installed so I've fished out the bag with my finger.

It's not the easiest thing to do but definitely doable and once the bag was out I confirmed that it has ruptured and losing crystals. Thankfully it looks like I caught it in time as the bag looks fairly full.

One thing I noticed is that there seems to be at least 3 varieties out in the wild: the straight seal like mine, the wavy seal and the x pattern seal. Not sure if one is stronger than the other.

Having called the dealer and requested a new tank with revision T and G13 flush I was told that unless they inspect the car for €140 they will not be changing the tank!

I declined and asked for the flush alone and was then presented with 2 options, a standard or 'advanced' flush. The latter takes 4h of labour so I went with the standard one, whatever that means for around €150. Hopefully this should get rid of the crystals that managed to seep through before I took the bag out.

IMG_4547.heic IMG_4548.heic

Updated image files

As the next generation of MK3 ownership continues, this issue is going to become more urgent. I removed a silica bag just as it was about to split on my 2017 VRS TDI and I was lucky.

 

To all owners who have not checked, please do and remove if your car is a single skinned tank.

Is there a definitive list of models, years and engines affected yet as that would be very useful for people to check

2 hours ago, skomaz said:

Is there a definitive list of models, years and engines affected yet as that would be very useful for people to check

Its effects all MK3's from 2013 to 2020.  Its completely random which type of header tank you get, although VAG have issued new revised capsules in the bottom of the latest gen of cars, ALL owners should be checking to see if the Silica bag is in existance.

 

As a straw poll:

 

Octavia TSI1.0 - no silica bag

Octavia TDI2.0 VRS - Silica bag - single skinned

Octavia TSI2.0 VRS - Silica Bag - double skinned (tank replaced)

Octavia TDI 2.0 Scout - Silica Bag - single skinned

Fabia 1.0TSI - no silica bag

 

Its a bit random to say the least.

 

Edited 19 May, 20215 yr by varaderoguy

1 minute ago, varaderoguy said:

There is a general rule of thumb here:

 

2013 to 2017 Pre-Facelifted Cars are usually effected.  All TDI engines have the issue - I've also seen the issue on a 1.4TSI engined car pre-FL.

Please note that if your car has had a waterpump replaced from this era of cars, then it will have a later revision of waterpump and the issue will be less of a problem.  Owners still report issues after 5 or 6 years though.

 

From 2017 to 2020, the cars were fixed with better revised water pumps.  They will still fail after 5 or 6 years though (dependant on mileage, driving style etc).

@varaderoguydid you mean to post this in the thread about water pump failure? This thread is about silica bags...

2 minutes ago, PetrolDave said:

@varaderoguydid you mean to post this in the thread about water pump failure? This thread is about silica bags...

I modified the thread - too many replying to different subjects, but I have corrected my original posting.

On 17/05/2021 at 09:31, lway said:

 

I ordered a replacement bottle from my local Skoda dealer and asked the Parts Guy to check that it didn't have the Bag in it, he asked me if I was worried about it splitting and blocking the system, he knew all about it but he said that the Skoda Mechanics had 3 different theories about how it happens and none of them could agree.

Theory 1 is the Silica Bag Splitting, Theory 2 is that it is sand left over in the system from the casting process and Theory 3 is that if the engine overheats  the coolant boils and it goes gloopy and blocks up the system.

 

He also said that Skoda would never admit to any of these.

 

But for under 40euro for a replacement tank I'll be replacing mine soon (once shops reopen and I can get a turkey baster  ) to eliminate Theory 1 from the equation.

 

 MINE WAS 100%  casting sand  as it continued after a flush and bag removal

On 26/01/2020 at 23:06, Jim Reire said:

 On a slightly different note, but on the same topic. as this silicate is essential to the normal performance of the antifreeze, but the  bags containing it ( where fitted ) are prone to leaking and causing havoc in the coolant system,  seems that there is an alternative to the plastic bag containing the silicate, and that's a capsule which  does the same job, but does not leak or split and disgorging the silicate into the system. Does any one have any information on this? A part Nr ? etc. 

 

@MassiveTurboLag

 

Quote

Having called the dealer and requested a new tank with revision T

 

Just in case you decide to buy one yourself the T revision was dropped on 01/02/2020 and the M revision is the latest revision as illustrated in this parts catalogue:

 

@bigade1

 

Thanks, realised after that I was mistaken and the parts guy confirmed M is the last version.

 

Going to have it done next week after another dealer quoted €476 for the same job thus making the €140 inspection fee seem like a bargain.

 

FML

On 19/05/2021 at 22:07, indars said:

 

 

Has anyone bought and tried this part yet?  Looks like it would just sit in the expansion tank and float around without a harness/holder.