Component Tests

Turbocharger Internal Oil Leak Test

NOTE: It is normal for a small amount of combustion gas to pass into the crankcase. This gas is scavenged into the air intake system through the PCV system, which incorporates an crankcase vent oil separator. Some engine oil, in the form of a vapor is carried into the air intake system with the blow-by gases (this engine oil also contributes to valve seat durability). This means that oil will collect inside the air intake components and the turbocharger. This is not an indication that the turbocharger oil seal has failed. The turbocharger oil seal will not fail unless the bearings fail first, which will cause the turbocharger to become noisy or seize. Do not install a new turbocharger due to oil inside the turbocharger or the air intake components. If a leak is detected in the oil supply or return tubes or connections, locate and rectify the source. Do not install a new turbocharger due to an oil leak.

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 SYSTEM - GENERAL INFORMATION or the following turbocharger check. If excessive oil is found in the turbocharger compressor outlet, check the CAC for oil contamination. If contamination is present, flush the CAC.

Check the turbocharger turbine outlet for evidence of oil. If excess liquid oil is present in the outlet, remove the turbocharger from the engine and examine the oil supply and return passages in the turbocharger, engine block and the turbocharger oil drain tube for restriction. If no restriction is found, install a new turbocharger. REFER to: Turbocharger .

Check for Free Rotation - Off Vehicle

NOTE: The turbocharger must be pre-oiled before carrying out this check.

NOTE: Turbine and compressor wheels must spin freely when turned by hand. No housing contact is permitted.

Inspect the turbocharger compressor and turbine fins for damage. If the compressor or turbine wheel fins are damaged, install a new turbocharger. REFER to: Turbocharger .

Rotate the turbocharger shaft, listen for bearing noise and roughness. If there is bearing noise or roughness a install a new turbocharger. REFER to: Turbocharger .

Press and rotate the turbocharger shaft. If either the compressor wheel or the turbine wheel contacts the housing, the bearings are bad and a new turbocharger must be installed. REFER to: Turbocharger .