Hi, after reading various horror stories about the silica bags splitting inside the coolant expansion tanks, and having a slight loss of cabin heat inside my Karoq, I decided to replace the tank, rather than trying to remove the bag and risk splitting it in the process. It's a really easy job to do and not really expensive - £33.29 for the tank, £7.44 for 1 litre of coolant. After replacing the tank I then removed the silica bag from the original tank, but fortunately it was still intact. It's made from fairly tough plastic/nylon , folded over and heat sealed along three sides, so you'd be quite unfortunate for it to split, although many VAG owners have had this happen.

What was apparent was the amount of crud in the bag and in the bottom of the tank. VAG must be aware of the silica bag splitting possibilities as, as far I'm aware, they do not produce the tank with the bag fitted any longer. As the cam belt & water pump will be replaced at the next service (5 yrs) I'm not concerned about the coolant needing any other additions to mix.

Even though it has not cured the heating problem, at least it's a relief that there isn't a bag full of silica balls swimming around the coolant system and heater matrix.

Hi Westie, just be aware that the service life of the coolant MAY be a little shorter without the silica bag fitted.   

Hi Warrior193, yes you may be correct about that but it should be fine for the time left before a coolant change when the water pump is replaced next December. Not sure about other VAG vehicles, but when I asked the Skoda parts guy he told me that they no longer sell the tank with the silica bag inside. Not sure if that's 100% correct or not but hey ho.