New Product Information
New Product Information
The purpose of New Product Information is to highlight, or indicate, important product changes from the previous model year.
Changes may include 1 or more of the following items:
* Torque values and/or fastener tightening strategies
* Changed engine specifications
* New sealants and/or adhesives
* Disassembly and assembly procedure revisions
* Engine mechanical diagnostic procedure revisions
* New special tools required
* A component comparison from the previous year
Torque Values and/or Fastener Tightening Strategies
* All fasteners and threaded holes on the LS4 engine utilize metric threads.
* Certain fasteners should not be used again. Bolts, studs, or other fasteners that must be replaced, will be called out in the specific service procedure.
* Some applications may use a second design camshaft retainer plate and bolts. Refer to Camshaft Installation (First Design) Camshaft Installation (Second Design).
* For second design engines, the camshaft sprocket is now retained to the front of the camshaft using a single bolt design with a torque and angle tightening strategy.
New Sealants and/or Adhesives
Sealers and adhesives, as required, are identified within the specific service procedures. Refer to Sealers, Adhesives, and Lubricants.
Disassembly and Assembly Procedure Revisions
* For second design engines, a new design timing chain tensioner replaces the timing chain dampener. Refer to Timing Chain and Sprockets Installation (First Design) Timing Chain and Sprockets Installation (Second Design).
* A new design inverted lip crankshaft rear oil seal is used. Refer to Crankshaft Rear Oil Seal Installation.
Engine Mechanical Diagnostic Procedure Revisions
All diagnosis on a vehicle should follow a logical process. Strategy based diagnostics is a uniform approach for repairing all systems. The diagnostic flow may always be used in order to resolve a system condition. The diagnostic flow is the place to start when repairs are necessary. For a detailed explanation, refer to Diagnostic Starting Point - Engine Mechanical. Initial Inspection and Diagnostic Overview
New Special Tools Required
* For second design engines, timing belt tensioner retaining pin EN 46330 is used to retain the timing chain tensioner during the installation procedure.
* Oil pressure gage adapter EN-47971 is used with the new design oil filter. The new design has the bypass valve internal to the oil filter.
A Component Comparison from the Previous Year
* First design 2007 LS4 engines contain the 2006 model year short nose camshaft, 3-bolt cam sprocket, timing chain dampener and 2006 LS4 front cover.
* Second design 2007 LS4 engines contain the long nose camshaft, single-bolt cam sprocket, timing chain tensioner, and new front cover.
* Some applications may use a second design camshaft retainer plate and bolts. Refer to Camshaft Installation (First Design) Camshaft Installation (Second Design).
* The camshaft sprocket has revised features to provide signal to the camshaft position (CMP) sensor.
* A new design timing chain tensioner replaces the timing chain dampener.
* The oil filter bypass valve is now internal to the oil filter.
* The manifold absolute pressure (MAP) sensor is now located in the top center area of the intake manifold.