Far be it from me to cry 'wolf', but while investigating a suitable location for an EGT thermocouple probe, I found this:
I sincerely believe, as the gynecologist said, that this bears looking into:
This is normal wear'n'tear for the compressor inlet duct at 68kmi, having been subjected to crankcase effluent for a good portion of those miles - it might behoove you guys to have a look at yours, as this won't play, clean air filter, or no.
Did find a suitable boss on the turbo exhaust flange, which would require removing the t\c for drilling\tapping, plus a matching hole in the exhaust manifold for the probe - it's between the two mounting-bolt holes on the cartridge-side of the flange