Last night I replaced the coolant tank for one without the "mit silikat" statement. I couldn't actually see a silicone bag in the old tank but I have heard that some are double walled and you can't easily see. So for some cheap piece of mind I decided to replaced it.

After installing the new tank and pouring in the contents of the old tank, I noticed some residue left over in the jug I used that looks very silicone like. I'm unsure of how to react to this, the car is now on 98k miles and the previous owner had owned from new looking after the car extremely well. Could I be safe in assuming he had removed the bag himself? Or do you think this has happened as a result of the bag exploding?

The coolant is a nice clean bright pink colour and the old tank showed very little fouling which I suppose is reassuring.

I do have a minor coolant leak, not sure from where but the water pump has not been replaced yet, which is the usual suspect.

I am taking the car on a long 1000+ mile trip this weekend and need to avoid any car troubles. Is this amount of residue worth worrying about? is there anything I can check? Just looking for any sort of advice right now.

Thanks in advance,

Matt

Unfortunately I cannot see the images that you uploaded, however my experience is that the bags are pretty robust, I have removed a few from expansion tanks and never had one split (but I am aware that they can degrade over time).

There is often some small amounts of residue in the expansion tank and if you have not had any issues to date and have replaced the expansion tank I would not expect you to suddenly have issues.