Manufacturer communication — 2006 GMC YUKON DENALI XL

Fitment confirmedReporter type: ManufacturerENGINEEQUIPMENT ADAPTIVE/MOBILITYFUEL 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

PIP5163B ・ fault and correction ・ for GM vehicles in general

Applies to

Applies to 2017 and prior GM passenger cars and trucks.
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Models: 2017 and Prior GM Passenger Cars and Trucks

Fault

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

Finding the cause

Possible causes

With dirt intrusion through a compromised air filtering system the engine wears out very quickly: grit is found in the intake runners and the bores look lightly sandblasted.
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Dirt intrusion- If the filtering system has been compromised the engine will wear out very quickly. You will find grit in the intake Runners and the cylinder bores will look lightly sand blasted.
If a catalytic converter fails and its brick breaks, the dust can be drawn back into the engine, and the bores look sandblasted.
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Catalytic Converter failure- If a converter fails and the brick is broken, the dust can be drawn back into the engine. A block showing this type of failure, will have bores that look to be sand blasted.

Steps to confirm (in the document’s order)

Cylinder damage or scoring shows as grooves in the cylinder wall deep enough to catch with a fingernail.
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Cylinder damage or scoring- the cylinder walls will contain grooves deep enough to catch with a finger nail.
An out-of-round bore has areas where the crosshatch is missing or worn; if crosshatch runs all the way around the bore from top to bottom, the bore is not out of round.
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An out of round cylinder bore- will contain areas where the cross hatch is missing or worn from different section of the cylinder bore. If there is crosshatch all the way around the bore from top to bottom the cylinder bore is not out of round.

Correction

Repair

With converter dust the back cylinders are affected first if caught early; otherwise no crosshatch remains and the engine must be replaced.
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Back cylinders go first if caught early. Otherwise there will be no Crosshatch and the engine will need to be replaced.

Caution

GM states it has had no issue with cylinders machined out of round in any engine family in recent history.
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Note: GM has not had an issue with cylinders being machined out of round for any engine family inrecent 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、失火、シリンダー漏れ、またはブローバイの原因として、シリンダーボアの損傷、スコアリング、または真円度不足の可能性があるエンジンブロックに関する情報を整備士に提供します。整備士はエンジンのシリンダー損傷またはスコアリング、シリンダーボアの真円度不足、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 that have a 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: 10114831
Received by source: 2017-08-15
Incident date: Unknown

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