Oil Leak At Turbocharger Air Intake Pipe - keywords 6.6 BQMI CAC charge clamp cooler crankcase diesel engine inlet LMM PCV positive rear seep seepage turbo valley ventilation

This PI was superseded to update Recommendation/Instructions. Please discard PIP4372A.

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

A dealer may encounter a customer concern of an engine oil leak. Initial inspection may reveal a leak that looks like it is coming from the rear of the engine. The leak may actually be coming from the turbocharger inlet pipe (Air Intake Pipe). This leak may run rearwards in the intake valley making the leak seem like a rear of engine oil leak.

Complete the current SI diagnostics for any trouble codes or symptoms found. Verify the leak is coming from the turbocharger air inlet pipe. The pipe is connected to the turbo with a band type retaining clamp. See SI illustration below.

Important: Oil in the charge air cooler, charge air cooler hoses, turbocharger, air intake pipe, or intake manifolds is normal with a closed crankcase ventilation system.

If the oil leak has been verified at the turbo inlet pipe complete the diagnosis below.

1. Check for an overfilled crankcase.
2. Verify the proper oil is being used per owner's manual specifications.
3. Check the breakaway torque of the Turbo Air Intake Pipe. Proper torque for this clamp is 15 nm or 11 lbf ft.
4. Inspect and verify the leak is NOT from the turbocharger oil return pipe.
5. Check for excessive crankcase pressure (water manometer Kent Moore tool number J-23951 or equivalent) using the current SI diagnostics for "Crankcase Ventilation System Inspection/Diagnosis."

If diagnostics were inconclusive, and a dealer has an excessive oil leak at the Turbo Air Intake Pipe, please call engineering directly. Contact information below.

Nate Hara

Cell phone

810-845-2545

If Nate does not answer please leave a short message with a phone number you can be reached at. If you don't hear back from Nate in four hours clean the sealing surfaces, reinstall the pipe, torque the clamp to 15 nm /11 lbf ft, and verify there is no leak. Release the vehicle to the customer to evaluate the repair. The loose clamp load on the band clamp may have been enough to induce this leak.

Note: Some oil accumulation on turbo inlet pipe is the result of a properly operating PCV system. Do NOT replace the turbo if the vehicle has an oil leak as described in this PI.

Note: Engineering may want to visit a local dealer that has a vehicle with the oil leak described in this PI. If your dealer is located within a 4 hour drive of the Detroit Metro area, and an oil leak (as described in this PI) has been verified, please contact Nate Hara before attempting any repairs.

Note: If a dealer was to encounter a repeat Intake Pipe oil leak after this repair was completed, make a field product report using the newest version of bulletin number 02-00-89-002.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.