Manufacturer communication — 2006 GMC YUKON DENALI XL

Fitment confirmedReporter type: ManufacturerFUEL SYSTEM, GASOLINE

Relation to the target vehicle

The source's vehicle field includes the trim.

Model year: Match 2006 — Source vehicle field
Model: Match YUKON DENALI XL — Source vehicle field
Trim: Match Denali — Source vehicle field

What the manufacturer’s document says

PIP5163E ・ fault and correction ・ for GM vehicles in general

Applies to

Applies to all brands and models, model years 2000 - 2021.
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All All 2000 - 2021

Fault

The block is suspected of cylinder bore damage, scoring or out of round as the cause of oil consumption, misfire, cylinder leakage or blow by.
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Suspecting an engine block of possible cylinder bore damage, scoring or out of round as the

Finding the cause

Possible causes

If a catalytic converter fails and the brick breaks, its dust can be drawn back into the engine.
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If a converter fails and the brick is broken, the dust can be drawn back into the engine.

Steps to confirm (in the document’s order)

The peak to valley spec for crosshatch is .65-2.8 microns; any deviation and the crosshatch will be gone.
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The peak to valley spec for crosshatch is .65-2.8 microns. Any deviation and the crosshatch will be gone.
Cylinder damage or scoring: the walls have grooves deep enough to catch with a finger nail.
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the cylinder walls will contain grooves deep enough to catch
If there is crosshatch all the way around the bore from top to bottom, the bore is not out of round.
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If there is crosshatch all the way around the bore from top to bottom the cylinder bore is not out of round.
Dirt intrusion: with a compromised filtering system the bores look lightly sand blasted, and the crosshatch is faint with no sharpness.
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the cylinder bores will look lightly sand blasted. The crosshatch will be faint and there will not be sharpness.
A block with this converter-dust failure has bores that look sand blasted.
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A block showing this type of failure, will have bores that look to be sand blasted.

Correction

Repair

If not caught early there will be no crosshatch and the engine will need to be replaced.
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Otherwise there will be no Crosshatch and the engine will need to be replaced.

Caution

GM has not had an issue with cylinders being machined out of round for any engine family in recent history.
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GM has not had an issue with cylinders being machined out of round for any engine family in recent history.

Compiled by reading the full text of the document; each point stands on the passage shown. Check the document itself, linked below, before working on a vehicle.

Stated content

Communication summary
本予備情報通知は、エンジンオイル消費量の増加、ミスファイア、シリンダーリーク、またはブローバイの原因となる可能性のあるエンジンブロックのシリンダーボア損傷、スコアリング、または円筒度不良についての情報を技術者に提供します。技術者はエンジンのシリンダー損傷またはスコアリング、シリンダーボアの円筒度不良、ダート侵入、およびキャタリティックコンバーター故障について点検する必要があります。 Machine translation (unreviewed)
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.
Go to this passage in the original

Source

Source: NHTSA Manufacturer Communications
Source reference: 10190437
Received by source: 2021-04-19
Incident date: Unknown

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