GMC Yukon XL 2000–2006

▸ENGINE1

1. Manufacturer communication2000–2006 GMC YUKON XL ・ 2018-05-21(1 earlier editions of this document folded here)

   Engine Block Cylinder Bore Damage Communication

   1. 1Fault

      • Leak
      • Misfire or rough idle
      • An engine block is suspected of cylinder bore damage, scoring or out of round as the cause of oil consumption, misfire, cylinder leakage or blow by.
      ↓→

   2. 2Finding the cause

      • Cylinder: defective
      • Engine Block: defective

      Steps to confirm (in the document’s order)

      1. Cylinder damage or scoring: the cylinder walls have grooves deep enough to catch with a finger nail.
      2. An out of round bore has areas where the cross hatch is missing or worn; if there is crosshatch all the way around the bore from top to bottom, the bore is not out of round.
      3. Dirt intrusion: if the air filtering system was compromised the engine wears out very quickly; grit is found in the intake runners and the bores look lightly sand blasted.
      4. Catalytic converter failure: if the brick is broken the dust can be drawn back into the engine, and the bores look sand blasted.
      ↓→

   3. 3Correction

      Repair

      • With converter dust the back cylinders go first if caught early; otherwise there is no crosshatch left and the engine needs to be replaced.

      Caution

      • GM has not had an issue with cylinders machined out of round for any engine family in recent history.
      • An oversize cylinder can only be confirmed by checking with an air gauge at the engine plant.
   Read the sentences of the record

   From the manufacturer’s document

   • Applies to：Applies to all models and engines, 2000 - 2018.
   • Condition：An engine block is suspected of cylinder bore damage, scoring or out of round as the cause of oil consumption, misfire, cylinder leakage or blow by.
   • Caution：GM has not had an issue with cylinders machined out of round for any engine family in recent history.
   • Confirm：Cylinder damage or scoring: the cylinder walls have grooves deep enough to catch with a finger nail.
   • Confirm：An out of round bore has areas where the cross hatch is missing or worn; if there is crosshatch all the way around the bore from top to bottom, the bore is not out of round.
   • Confirm：Dirt intrusion: if the air filtering system was compromised the engine wears out very quickly; grit is found in the intake runners and the bores look lightly sand blasted.
   • Confirm：Catalytic converter failure: if the brick is broken the dust can be drawn back into the engine, and the bores look sand blasted.
   • Repair：With converter dust the back cylinders go first if caught early; otherwise there is no crosshatch left and the engine needs to be replaced.
   • Caution：An oversize cylinder can only be confirmed by checking with an air gauge at the engine plant.

   Open the manufacturer’s document (PDF) ↗ The points above were read from this document.

   Remedy

   This Preliminary Information communication provides information to the technician about engine block of possible cylinder bore damage, scoring or out of round as the possible cause of engine oil consumption, misfire, cylinder leakage or blow by. Technician will need to inspect the engine for Cylinder damage or scoring, An out of round cylinder bore, Dirt intrusion, and Catalytic Converter failure.