Turbocharger: Testing and Inspection

Visually inspect the following points of the turbocharger system:

Intercooler Ducts:

AIR INLET SIDE
^ Check the air filter element to make sure that it is clean. If it is not clean replace it.
^ Check that there are no cracks, rips, cuts, or holes in the air inlet hoses or intercooler hoses. If there are any openings in the inlet hoses after the air cleaner element or turbocharger, debris can be sucked in and cause damage both to the engine and the turbocharger. If there are any leaks in the hoses, replace them.

TURBOCHARGER PRESSURE SIDE
^ Check that there are no leaks on the pressure side of the turbocharger. Apply liquid soap to the crossover tube, manifold cover sealing surfaces, intercooler hose, intercooler, and connections. If bubbles come out of any of these places, there is an air leak. Repair or replace as needed. Some symptoms that could indicate a leak on the pressure side of the turbo are: Excessive smoke and low power.

MANIFOLD AND TURBOCHARGER EXHAUST SIDE
^ Check for exhaust leaks and restrictions at the manifold and turbocharger. Exhaust leaks can usually be detected audibly or by discoloration of the manifold or turbo. Some symptoms that could indicate exhaust leaks are: Excessive smoke, low power, and low manifold pressure.

TURBOCHARGER
^ Remove the air inlet hose and check the compressor and the housing for wear. Rotate the compressor to make sure it rotates freely. If wear is indicated on the turbocharger housing, remove and repair the unit.
^ Check the oil return line for restrictions or leaks. Repair as necessary.
^ Check for intake or exhaust restrictions. High restrictions in either the intake or exhaust can cause a high vacuum between the compressor and the turbo housing, causing oil to leak by the seals. Remove the air inlet hose and intercooler duct and check for oil on the compressor impeller or intercooler duct. If oil is found, locate and repair the restriction.
NOTE: Excessive fuel on the exhaust side of the turbocharger will look like oil leaking by the seals. This condition can come from injector overfueling or excessive engine operation under "no load" conditions.
^ Check for excessive turbocharger noise. The turbocharger will normally make a "whining" noise that varies in intensity depending upon engine rpm. If there are any "clunking" noises or rattles when the engine is revved up, check for loose turbocharger mounting bolts, intake, or exhaust leaks. Lower pitch noises or rattles at slower engine speeds can indicate debris in the system or that the rotor is contacting the housing. Before removing the turbocharger, perform steps 9 and 10 consecutively.
^ Check the turbocharger rotor end play with a dial indicator. If the end play is outside of specifications, repair or replace the turbocharger.
^ Check the turbocharger rotor radial clearance with a dial indicator. If the radial clearance is not within specifications, repair or replace the turbocharger.