Holset HX25 - Visual Checks

Exhaust Gas Leakage
Turbine housing flange leakage will cause soot
formation on the flange. Check exhaust manifold to
flange seal ensuring fastener torque meets engine
manufacturer’s recommendation.
Check flange for cracks and ensure flatness is within
0.1 mm (0.004 in).
Check turbine housing gasket for signs of damage
which would cause leakage. Always replace damaged
gaskets.
HX25/25W/27W Service Repair Manual Component Testing and Replacement
4:3
Visual Checks
Check for cracked, bent or damaged compressor wheel
blades.
Where practical, check for cracked, bent or damaged
turbine wheel blades.
With intake system disconnected from compressor
housing, it may be possible to check visually for excess
bearing axial and radial clearances.
If light finger pressure causes contact between
compressor or turbine wheel with respective housing,
replace turbocharger.
If in doubt, the turbocharger must be removed from
engine to check bearing clearance against
recommended values shown in Service Data Sheet.
Caution
Never attempt to straighten blades.
Caution
Never attempt to straighten blades.