Header tank and silica bags

dErZ

dErZ

VCDS User
VIP Member
T6 Guru
While I was wasting my life last night flicking through facebook, I came across a post about there being silica bags in the header tank on alot of newer VW vehicles and the subsequent problems with peoples water ways and heater matrix's. (I havent checked mine yet)

Has anyone had the same problem?

for reference

www.briskoda.net

Header Tank Silica Bag Fault

Hi guys, I don’t want to go over old ground with this and I have learnt much from other threads on this issue but have one unanswered question. As the title suggests I have the heater matrix silica bag bursting issue on my 2014 2.0 TDI, confirmed by my local Skoda dealer. The only issue I have at...
www.briskoda.net www.briskoda.net

Burst silica bag - can't get it solved

Hi, I'm new to this so I hope I'm doing this right. I have a 2013 Mk7 1.6TDI golf. My heating stopped working about 5 weeks ago and I took the car to a mechanic who found it was a burst silica bag. To fix this, he replaced the heater core and flushed the system thoroughly, until he was sure it...
www.golfmk7.com
 
I felt compelled to check mine a while back after seeing an earlier iteration of that post. Nothing found (2018 TSI panel van).
 
OMG, sometimes this forum and other social media gives me things to worry about I never knew existed :(

Edit: I will have to check mine. God help me if there is one in there.
 
Timing belt and water pump change at 4 years (if on VW UK schedule), doing the coolant change at the same time make sense.
I can’t see why the silica additive would be needed in that case.
I suspect more will end up being burst during removal than those that burst in service.
 
DXX said:
Timing belt and water pump change at 4 years (if on VW UK schedule), doing the coolant change at the same time make sense.
I can’t see why the silica additive would be needed in that case.
I suspect more will end up being burst during removal than those that burst in service.
Click to expand...
Thats my worry.
 
Lots of info on Briskoda. Two things I’ve picked up..

- the header tank usually has ‘mit silikat’ printed on it if it contains the bag.

- its a 20min job to drain and remove the tank and do it on the bench.

I’ll be checking the van and Octavia today.
 
Paynewright said:
Lots of info on Briskoda. Two things I’ve picked up..

- the header tank usually has ‘mit silikat’ printed on it if it contains the bag.

- its a 20min job to drain and remove the tank and do it on the bench.

I’ll be checking the van and Octavia today.
Click to expand...
If you have one and decide to remove will you be doing a ‘how to’?
 
seen the posts as well, it says it should be pretty visible in the tank and have a specific code on the header tank but i cant see anything.

1B6B3D04-D9A5-45A5-9674-94E9CEB8942D.jpeg8CECFEC4-D857-46FA-97E4-744F82E18F68.jpegC7619242-8264-474D-82D0-A9722630BED2.jpeg

2F6216CF-03A7-4E51-8125-65D6F7D29C7C.jpeg
 
This is apparently why it is there (from vwroc.co.uk):

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.

I guess removing it and changing your coolant more frequently is one way to avoid it, you can also apparently get a tank with the silicon held in a seperate chamber from VW as an alternative.
 
You can’t see it from the top but if you shine a torch through the side of the expansion tank then you can. My tank has part number 7e0 121 407 b printed on it but I can’t see mit silikat printed on it anywhere. The bag is on the left by the light source. This is on a 150ps Shuttle.

I’m a bit nervous now I’ve found this….

C0CB5F15-7B87-4D78-AC14-5C6723917242.jpeg
 
Broadside said:
You can’t see it from the top but if you shine a torch through the side of the expansion tank then you can. My tank has part number 7e0 121 407 b printed on it but I can’t see mit silikat printed on it anywhere. The bag is on the left by the light source. This is on a 150ps Shuttle.

I’m a bit nervous now I’ve found this….

View attachment 142532
Click to expand...
Thanks for the pic, that helps!
 
Well I’ve checked the van and the octavia. Van has one, Octavia doesn’t.

Funnily, I took the cap off the van header tank yesterday and couldn’t see anything. Backlit with a torch and its obvious. Its located behind two plastic prongs towards the front of the tank (grill /bumper end).

If its not F freezing tomorrow I’ll whip the tank off and extricate it - with pictures / write up to follow!

20D00617-DE6F-4B31-BFFB-A22A17986483.jpeg
 
So, bag out and all done in 30mins which included OCD cleaning of the tank inside and out.

- drain tank - I used a cheap oil syringe that was rubbish. I’d just syphon if doing again. Tank holds well over a litre so ensure receptical is big enough (and clean). Try and get the syphon pipe down the hole in the bottom of the tank to reduce spills when you remove it.

- two little hoses to remove on the top of the tank. Use the waterpump pliers to squeeze the clips up and move along the pipe. By hand twist the pipe first to break the seal then pull off.

- Remove the low coolant electrical connector. I find pushing it on, release the clip then pull off usually works best. Release the cable which is seated in a groove in the tank.

- unclip two hoses from the battery side of the tank.


- Remove the two torx 25 self tappers at the front of the tank. The tank is then pulled upwards to release it (two posts moulded into the tank need to pull out of the mounting holes.

- Remove the thicker hose on the bottom of the tank after sliding the clip down with the pliers.

- twist and pull upwards and tank should be free.

- Use forceps to remove bag. I sort of pushed it to one side then locked the forceps on and pulled it out from the retaining prongs. Then manouver it so the thinnest end is upwards and pull out of the tank with the forceps. I needed to fold the corner of the bag over to get it through the hole.

- I noticed some debris in the tank that wouldnt flush out so used the long paint brush and bottle brush to clean it.

- Refitting is reverse of removal. Refill tank with saved coolant and top up if necessary deionised water / fresh coolant

Tools (syringe not shown)
80DFBD51-14EB-42EC-933E-57F15CFEEC8A.jpeg
 
You must log in or register to reply here.

Similar threads

F
Hello all. This is going to be a Buy/Sell/Conversion post
Replies
4
Views
1K
Bav
Bav
Skyliner33
Looking for a caravan? Funny eBay ad
Replies
12
Views
5K
russvphoto
russvphoto
Back
Top