van came in for a cam belt and on starting we have no oil pressure. we have flow but no pressure. we thought the problem was snapped turbo shaft and oil pouring into exhaust but turned out to be a red herring we fitted a new pressure relief valve to no effect. fitted a pressure take off at oil filter and blocked main gallery to check if pump gears were worn (do not look so) and sure enough we got 80 psi. its as if there is a massive hole somewhere along the main oil gallery stopping oil from building pressure and reaching upper engine components. we smoked the gallery from the filter and got masses of smoke coming from crankshaft rear main area its a bit of a puzzle - anyone any ideas !!! struggling to say least and reluctant to strip engine at this moment ken hudson