I've just had a second new engine fitted to my VW Transporter water cooled camper van after the first new engine overheated. I told the garage that the engine was running too hot but they assured me it was ok. Now with the second engine I feel that it is still running too hot and live in dread of it boiling up again. The temperature gauge is reading between 90 and 100 as soon as it gets warmed up. I've run it for one week now, the longest journey being 20 miles. What do you think?
I would be tempted to notify your garage in writing of all the details as mentioned here, present it to them and ask for their advice and ask them to write their advice down also stating that they have noted your concerns, be sure to get a signature and the name of the person signing it.
With the water cooled VW Transporter you have to be very carefull to bleed all of the air out of the cooling system. As I recall there are bleed screws at the top of the engine and also at the top of the radiator behind the grille.