1.5dci came in with no power, wouldn’t rev above 1500rpm, fault codes p2263 and p0106, with ignition on boost pressure matched atmospheric pressure, with engine running the boost pressure dropped, rev the engine it and it dropped more, looked under the bonnet with engine running and the boost pipe from intercooler to throttle body was sucked in, disconnected the pipe going into the intercooler and it was the same, removed the pipe after the intercooler and it revved fine, quick check of the inside of the intercooler with the borescope revealed this absolute mess. Obviously the intercooler being blocked is the cause of no power and the fault codes but it is a symptom of something else failed/failing. Question, what would be the next step to finding the cause of the inlet side of the intercooler blocking up with what looks to be soot or carbon?