Had a C5 HDi towed in with report that engine would not start.... After a bit of interrogation was revealed that car had been overheating, so owner decided to give radiator a flush, with garden hose.... He takes of what he 'THINKS' is top hose and shoves garden hose down it and turns tap on full bore... When no more water would go in, re-fits hose and tries to start it up.... Problem was the 'top-hose' he thought was radiator hose was hose from inter cooler to engine intake.... And he had filled up inter cooler and inlet manifold with water... Then when tried to start it caused hydraulic lock and has caused some internal damage...to what extent not yet known!.... But it is sounding a little expensive!