thank you ric355! I'll investigate further this evening!

I had this problem on my 2002 TD6 which took me 5 months of testing and changing components to find. Eventually I got fed up with it and decided to replace the intercooler hoses. The fault was eventually traced to the seal in the hose end cap not making good when pushed onto the intercooler tube. I don't know if your tdv8 has same quick release couplings on intercooler hoses but I would get them checked/replaced. The Best 4x4 by far, so long as you have deep pockets.