At 97,000km the on-board computer alerted me to 'low-coolant' regularly. Problem diagnosed to leaking water-pump seal. VW dealer replaced whole pump under warranty.
At 150,000km the auto-trans developed a pause between 3rd and 4th gear (about 1 second) and the ventilation fan stopped working. Took it to servicing VW dealer, who ran a diagnostic on both and said they would send results through to VW Aust. and would call me back. Seven days later, received a call to 'bring the van in for a new transmission and fan motor to be fitted under good-will'. It was 50,000km out of warranty. This service alone has lured me back to VW when the van comes up for replacement.
It continued to run faultless 'til 225,000km when diesel exhaust fumes started entering the cabin whilst idling. Problem was a crack in the exhaust near the turbo. Fixed at VW/Audi specialist for roughly $600.
Now just recently air-con compressor died (van is black with black windows and a sunroof and air-con runs a lot, especially in recent super-hot summers Melbourne has experienced).
Now, having just fixed air-con, alternator went.
All things aside, think this van has been pretty good reliability wise. It has never seen a tow-truck, unlike my Merc which saw four in the same number of k's.
I have really enjoyed having this van as my company vehicle. It drives like a good car with good steering feel, instant response from the TDI motor, good interior layout, and a very sure-footed on-road feel; and incredible brakes.
It weighs in at 1900kg empty, but returns consistent figures like 9.0lt/100km in a mixture of city/freeway running. My best tank was 1026km from 78lts.
Whilst off the road for transmission change, I hired a Toyota Hi-ace van for 2 days so I could continue my duties. The gap between these two vehicles is remarkable! The only reason you would buy the Toyota is for its reliability. Aside from that, they are crap!! Noisy, high floor, uncomfortable, and unstable; on a gentle climb up a mainroad with tram-tracks, in traffic, doing 50km/h, and slightly wet, the empty Hi-ace hit the tram-tracks and decided to step out sideways to an almost 45' angle. I consider myself to be a good driver with a good sense of what my vehicle is doing, and this behaviour took me totally by shock!!! Very dangerous! It scared the crap out of me. The Transporter shows nothing but car-like competence on the road.
Its maintenance cost are definitely on the steep side, but if you are prepared to accept that, the trade-off is a van you will happily sit in for hours on end and happily jump into, with a smile, every morning!!