VAG expansion tanks: Motoring Motoring Discussion forum

Motoring Discussion > VAG expansion tanks	Miscellaneous
Thread Author: Bobby	Replies: 7

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Wed 14 Jul 21 12:24

VAG expansion tanks - Bobby

Talking to my indie today.

He was telling me he has a load of VAG cars, Inc many taxis, in for changes to the expansion tank.
Apparently for some reason VAG are now selling their cars with a silica compound pack within the tank. And of course, there are now cases where this has burst and wrecked engines.

He is replacing the tanks with non silica versions.

Can’t get my head round this at all unless I am only getting half the story!

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Wed 14 Jul 21 13:00

VAG expansion tanks - Lygonos

Silicate bag replenishes the alloy-protecting stuff in the coolant as it is used up.

Seems like overkill if you change the coolant every 5-10 years.

Could always switch to a non-waterbased coolant...

en.wikipedia.org/wiki/Waterless_coolant

Last edited by: Lygonos on Wed 14 Jul 21 at 13:01

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Wed 14 Jul 21 13:24

VAG expansion tanks - Zero

First started appearing in VAG engines about 10 years ago, MB use them as well and it isnt a significant problem, in fact better that than people not changing their coolant at specified intervals

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Wed 14 Jul 21 18:35

VAG expansion tanks - Rudedog

From the GTi forum I'm on the issue might effect the heater matrix by blocking it, I won't be messing with mine.

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Wed 14 Jul 21 22:34

VAG expansion tanks - Dave_

>> From the GTi forum I'm on the issue might effect the heater matrix by blocking it, I won't be messing with mine.

It's the same on the Skoda vRS groups. I'm not planning on removing mine either.

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Wed 14 Jul 21 22:36

VAG expansion tanks - Bill Payer

>> From the GTi forum I'm on the issue might effect the heater matrix by blocking
>> it, I won't be messing with mine.
>>
It's the silica being released that blocks the heater matrix.

Apparently the tanks are marked - nothing on wife's Tiguan.

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Thu 15 Jul 21 10:07

VAG expansion tanks - Rudedog

Yep should be marked 'mit silikat' if it has it.

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Thu 15 Jul 21 10:13

VAG expansion tanks - Zero

>> It's the silica being released that blocks the heater matrix.

Just like not changing the coolant then.

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