6.6 LLY Engine Oil Pump Lock Up From Turbocharger Debris - keywords SES noise bearing wheel rub low power smoke pump pressure knock P0045 P0046 P2563

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

A vehicle may be brought into the dealer for a noise, SES light, or low power. During diagnosis, the dealer may find turbine (exhaust side) wheel rub damage, a broken turbine shaft, or a turbo bearing concern. Turbocharger shaft, turbine wheel rubs, or bearing concerns may cause no oil pressure. Debris from the turbocharger can get into the engine crankcase oil and lock up the engine oil pump. The source of the debris is a piece of the turbine seal ring. These seals are not typical rubber lip seals. They are merely square metal rings with a split end gap just like a piston ring. A piece of the broken ring may be carried to the engine crankcase in the turbo return oil. The ring can then be picked up in the oil pump pick up and delivered to the oil pump. When the oil pump suddenly locks, it will loosen the oil pump driven gear nut due to the gear rotation.

If a 6.6 LLY turbo has been diagnosed with turbine (exhaust side) wheel rub damage, a broken turbine shaft, or a turbo bearing concern complete the steps below:

1. Remove the turbocharger.
2. Verify the cam bearing that supplies the oil to the turbo has not spun in the block. (Bulletin # 03-06-93-001A)
3. Inspect and clean the turbo oil return pipe.
4. Visually inspect the turbo oil return hole in rear engine cover for debris and clean as necessary.
5. Remove the lower steel oil pan and inspect for debris.
6. Clean lower pan as needed.
7. Add fresh oil and install a new oil filter.

If all the turbo debris has been cleaned from the engine and the engine oil pressure is normal, the oil pump will not need to be replaced.

If the turbo debris has caused the oil pump to lock up, the oil pump and the oil pump drive nut will need to be replaced. The oil pump drive gear should always be reused unless it is damaged. If the oil pump is being replaced inspect the oil pump pickup tube for any remaining debris.

Note: If the compressor (intake side) wheel has significant damage with missing material or blades, it will be necessary to clean the Charge Air Cooler (CAC) pipes and Charge Air Cooler. Missing material, blades, or excessive oil in the CAC system must be cleaned prior to starting the engine or additional turbo or engine damage may occur.

Note: The LLY engine has a closed PCV breather system and some oil residue in the turbo inlet and CAC system is normal.

Please follow this diagnosis 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.

(2004-2005 Chevrolet Silverado) and (2004-2005 GMC Sierra) and (2004-2005 Chevrolet Kodiak) and (2004-2005 GMC Topkick)