Michel
I did not know of any specific websites for van faults. If like me you wanted to buy say a Ford Transit, type into google, Ford Transit faults and one of the web pages will give you the info you need. I paid about £5 for a 12 page report which once i used my credit card, you download it then print out.
Had i had done this before buying the van, i might have saved a bit of money, however a recon box will last the rest of the vans life and the trade in price would be pretty low against a new one.
One thing that the report told me about Vivaros was that the glow plugs are about £1000 to replace and the injector pump £4000. Obviously shopping around would reduce this.
The main dealer wanted to charge me £4000 for a new box with fitting.
Hope this is of use to you
Dave