Leaks in the intake air system are most commonly identified by:
ā¢ Inspection of piping for cracked or loose clamps
ā¢ Applying a solution of soapy water in the suspected area and inspecting for bubbles
ā¢ Listening for a high-pitched whining or sucking noise in the suspected leakage area.
Engine intake air must be filtered to keep dirt and debris from entering the engine. If intake air piping is
damaged or loose, unfiltered air will enter the engine and cause premature wear.
Inspect the inlet air piping for cracked hoses and damaged or loose clamps.
Operate the engine at high idle and use a solution of soapy water to spot inlet air leaks.
If an air leak exists at the turbocharger fresh air inlet, the soap bubbles will be drawn in with the air.
Torque Value: 10 Nā¢m [ 89 in-lb]
Check for corrosion of the inlet system piping under the clamps and hoses. Corrosion can allow corrosive products
and dirt to enter the intake system.
Disassemble and clean as required.
Operate the engine at full throttle and rated rpm with maximum load.
Listen for a high-pitched whistling noise from the turbocharger, nearby piping, and connections.
Apply a soapy water solution to sealing surfaces and inspect for bubbles.
Leaks can also be found at the turbocharger compressor outlet connection.
Inspect for damage, replace the sealing a-ring, and tighten any loose clamps.
Torque Value: 10 Nā¢m [ 89 in-lb ]
Charge-Air Cooler Tubing or Connection Hoses
ā¢ Inspect the hose and tubing for damage. Refer to Procedure 010-019 in Section 10.
ā¢ Tighten loose clamps.
ā¢ Refer to the equipment manufacturer’s specifications for the correct torque value.
Air Intake Connection and Air Intake Connection Adapter
ā¢ Inspect for damage.
ā¢ Tighten loose clamps.
ā¢ Replace the connection clamp, if necessary.
Intake Manifold
ā¢ Inspect for damage.
ā¢ If damage is found , replace the gasket, if the engine was originally equipped with a gasket.
Closed Crankcase Ventilation System
Inspect the crankcase ventilation line which attaches either to the turbocharger compressor housing or the
OEM air inlet plumbing for cracks and leaks.
Replace as necessary.
Exhaust System
Leaks in the exhaust system will cause the turbocharger to operate at a lower speed, reducing the amount of air
going to the cylinders during engine operation.
Operate the engine at full throttle and rated rpm with maximum load.
Leaks can be identified by noise or discoloration caused by the escaping hot gases.
Leaks can be found at:
ā¢ Exhaust manifold gaskets
ā¢ Exhaust manifold slip joint, if equipped.
Use the following procedure for proper repair technique, if the slip joint on the exhaust manifold is leaking. Refer to
Procedure 011-007 in Section 11.
ā¢ Turbocharger mounting gaskets
ā¢ Turbine housing sealing surface
ā¢ Turbocharger compressor housing
EGR components:
ā¢ EGR connection tube gasket
ā¢ EGR coolant inlet gasket
ā¢ EGR coolant outlet gasket
ā¢ EGR valve inlet gasket
ā¢ EGR valve mounting gasket
ā¢ EGR differential pressure sensor gasket
ā¢ Exhaust pressure sensor plumbing.
If failure resulted in coolant, oil, excessive fuel or excessive black smoke entering the exhaust system, the
aftertreatment system must be inspected. Refer to Procedure 014-013 in Section 14.