Replacing coolant tank with Silicon bag

[silver38]

I went to a dealer last Friday and bought a new tank @ retail £23.06 + vat total price £27.67.
The current part number is 5Q0121407T, there has been a part number ending in M. I checked while there for the silica bag and couldn't see one, the parts guy said there had been quite a few cars that needed the heater matrix changed because of the split silica bag. The bag isn't available separately but all tanks have it. Check for the handbook information symbol  on the tank to the right you will also see the G13 symbol and further to the right the words mit silikat (with silicate).

[Rob_benton]

I went to a dealer last Friday and bought a new tank @ retail £23.06 + vat total price £27.67.
The current part number is 5Q0121407T, there has been a part number ending in M. I checked while there for the silica bag and couldn't see one, the parts guy said there had been quite a few cars that needed the heater matrix changed because of the split silica bag. The bag isn't available separately but all tanks have it. Check for the handbook information symbol  on the tank to the right you will also see the G13 symbol and further to the right the words mit silikat (with silicate).

So did your old tank have a bag ? And if it did, are you fitting a tank without one ?

[Pretzel]

Does anyone have a picture or a link to a picture showing this bag, as I'm feeling a little paranoid!

[SRGTD]

Does anyone have a picture or a link to a picture showing this bag, as I'm feeling a little paranoid!

Here’s one being removed on a US GTI;

https://www.youtube.com/watch?v=-GWRejR7U0w

[Rob_benton]

Does anyone have a picture or a link to a picture showing this bag, as I'm feeling a little paranoid!

If your tank has a bag it will say mit silikat next to G13 written on it.

[golfdave]

Just checked my car a 2014 build estate..coolant tank does not state "mit silicat"...& shone a bright torch through the side of the tank to illuminate the whole inside...no silica bag...& I have the top end 2 zone climate...as someone thought all with climate got the silica bags as standard...

VW obviously considering a silica bag is cheaper than the correct amount of G13...extreme penny pinching...which also explains the lack of service date change for the coolant which used to be 5yrs....

[Rob_benton]

This is from a Vw self study

‘ 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.’

[golfdave]

This is from a Vw self study

‘ 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.’

Basically "we don't need to change the coolant every 5yrs.. a silica bag does the job of keeping the coolant tip-top"....right up until it splits & FUBARs the entire heating system usually when the car is out of warranty….

[Toppy]

This is from a Vw self study

‘ 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.’

Basically "we don't need to change the coolant every 5yrs.. a silica bag does the job of keeping the coolant tip-top"....right up until it splits & FUBARs the entire heating system usually when the car is out of warranty….

An excellent summing up of the situation there Dave 

[Crazyfool]

Hello, first time poster here. Had my car in for a service the other day got a call to say the bag had burst and the coolant was contaminated. They replaced the tank and coolant under warranty car has 30000kms on it 2 years old. Its only a 1 litre just thought some may be interested.