Its a 2002 TD27 turbo intercooler with bosch manament, diagnosed with consult 2
So it goes into limp mode only after its warmed up giving a fault about turbo pressure
It resets limp mode when you turn ignition off and on again ok for 30 secs, then power loss again, rinse and repeat. But its fine for the 10 or so miles its takes from cold to reach max working temperature, so its only when warm.
This makes me think the boost loss is happening when something metalic is expanding and opening up a crack.
I'n my attempts to sort this problem so far I've had intercooler tested and its fine, replaced inlet manifold gasket, resealed throttle body, removed flap spindle from throttle body and filled holes with chemical metal. Remove EGR valve completely and plated the inlet and exhaust holes with a 4mm tick blanks that i bolted and sealed with copper rtv.
What else could be causing boost loss after reaching full temp ?