2018 Passat B8 2.0 TDi 150PS - Brown Coolant and Stained Coolant Bottle

[Andy Cook]

I bought a 2018 150PS 2.0 TDi Passat B8 Estate just over 2 months ago with 33k miles on it from one of the major supermarkets and it is just coming to the end of its 3 month warranty period. After a trouble free 5k miles, more or less from cold this morning it dropped a Low Coolant message. When I popped the bonnet the coolant expansion tank externally looked like it was at the maximum mark. However, once I got the lid off (it was remarkably tight - I couldn't open it by hand), I realised that I was just looking at staining at the maximum level on the header tank bottle and the actual coolant level was a lot lower. I topped the tank up, but the coolant is brown rather than pink / purple, and I suspect it may have been like that since we got it. I'd noted the darker colour visible on the bottle, but simply assumed that was the different colouring between G12 which I was familiar with and G13 - I didn't bother to open it...

I'll report the issue to the warranty provider so that they have the issue on record FWIW, but I expect I'll get a message to monitor the level... The car had the oil and filter changed when we got it and it is due another service in 88 days / 4k miles, but I figure I should get the coolant system flushed and refilled sooner.

Any further suggestions / concerns? Sllghtly paranoid since the reason for buying this car was that our 2006 B6 Passat at 232k miles was starting to loose a little coolant (and the wheel arches are going rotten) and our 2009 Golf Mk 6 at 106k miles is losing coolant at quite a high rate (and it's not the EGR cooler or anything obvious) ;-(

[Crasher]

It may have G13 coolant in it and this can look like rusty sludge but if in doubt, back flush it clean, blow through with compressed air and refill with G12 Evo and distilled water.