Engine - In Vehicle Cylinder Head Service Procedure: Overview

Bulletin No.: 07-06-01-019

Date: September 13, 2007

INFORMATION

Subject:
Information On New In-Vehicle Service Procedure for Removal/Installation of LLV, LLR Cylinder Head

Models:
2007 Chevrolet Colorado
2007 GMC Canyon
2007 HUMMER H3

with Vortec(TM) 2.9L I-4, 3.7L I-5 Engine (VINs 9, E - RPOs LLV, LLR)

The following new service information outlined in this bulletin will aid technicians in removal and installation of the cylinder head without the removal of the front engine cover. The new service procedure can be done in vehicle with the aid of a new General Motors special service tool part number EN-48464 - Lower Timing Gear Tensioner Holding Tool.

If the Lower Timing Gear Tensioner Holding Tool is not wedged correctly, the front cover will have to be removed to reset the timing chain tensioner.

The Lower Timing Gear Tensioner Holding Tool will wedge between the timing chain tensioner and the front cover center bolt. When wedged in place, this will allow the camshafts or cylinder head to be serviced or removed without the removal of the front cover to reset the timing chain tensioner.

It is very important to make sure when timing the engine that all your timing marks align; there is no margin for error. If timed incorrectly, damage to the engine may occur or a DTC P0017 may set (PCM uses the crankshaft position (CKP) sensor and the exhaust camshaft position (CMP) sensor information to monitor the correlation between the crankshaft and camshaft positions).

Tools Required

The following tools will be required to perform this new service procedure outlined in this bulletin:

EN-48464 - Lower Timing Gear Tensioner Holding Tool

EN-46547 - Flywheel Holding Tool

J 44221 - Camshaft Holding Tool

J 45059 - Torque Angle Meter

TDC Indicator Tool (Some models may use a dial Indicator or graduation marks on the side of a sliding shaft for visual indication)

SI Documents








Before starting this new service procedure outlined in this bulletin, refer to the SI documents as shown and review. Print the SI documents with an asterisk (*) next to the document. The asterisk indicates additional service information shown in this bulletin.











Parts Information

Warranty Information





For vehicles repaired under warranty, use the table.





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