Turbocharger Internal Oil Leak Test
WARNING: This page is about a different car, the 2007 Ford Pickup, 2007 Ford F550 Super Duty, 2007 Ford F450 Super Duty, and 2007 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Some engine oil may be present in the turbocharger compressor inlet and in the air inlet components due to the crankcase breather system.
Check the turbocharger compressor inlet for evidence of oil. If excessive oil is present, this indicates that the failure could be in the engine or turbocharger. Refer to ENGINE - 6.0L DIESEL article or the following turbocharger checks. If excessive oil is found in the turbocharger compressor outlet, check the charge air cooler (CAC) for oil contamination.
Check the turbocharger turbine outlet for evidence of oil. If oil is present in the outlet, remove the turbocharger from the engine and examine the oil supply and return passages in the turbocharger and engine block for restriction. If no restriction is found, install a new turbocharger.