Rather than start a new thread. I'll resurrect.....
I have a very similar issue after 400 miles total !!!!!
Low Coolant warning suddenly coming on with no other symptoms beforehand. Van was with the ceramic film people at the time. They told me it had come on when they moved it out of the studio ready for me to collect. They run Transporters, so kindly topped up for me (assume to max level). Didn't think any more of it. Went to collect, started fine but there were comments that exhaust was a bit white not clear. Not thick white plumes, more a bit steamy looking (without wanting to be leading in that description).
Drove home 20.6 miles. Parking up and low coolant light came on !! Looked in reservoir and it was basically half full and therefore well below 'min'.
Immediately looked under van and around reservoir .... nothing to be seen in the way of a leak.
Rang VW who said top it up and drive it to the nearest local dealer. Rang Leighton Vans who said do not top it up, do not try and start or drive it.
Van trailered to selected dealer. Been there a week no news ... they claim VW are making them jump through hoops
Do some research on this and find very likely EGR Cooler. Could be something even worse also I guess??
In my technically ignorant and simple way, I distill this down after hours of Google research :
The coolant must've gone somewhere ? Apparently, it's the Engine, Gearbox or Exhaust.
If it is the EGR Cooler and it's replaced, this doesn't take into account any damage done to Engine, Turbo's, Exhaust or Gearbox..... by the coolant being there.
Therefore, even if the EGR Cooler is replaced, you are very likely left with a van that has damage to one or more of these systems. The degree of damage will dictate when in the vans life you will suffer the consequences.
As we all know, every single one of these items is a big £number to sort out and that excludes any aggro from possible breakdown on a long trip.
I also understand this is a common well understood problem VW are trying to brush under the carpet and fob us all off .
Am I pretty much bang on, bar technical details...... ?