New Product Information. Chevrolet Express 2003

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 2003 🢒 Express 🢒 Engine 🢒 Engine Mechanical - 4.8L, 5.3L, and 6.0L 🢒 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 one 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 4.8/5.3/6.0 liter engines utilize metric threads.

•	Cylinder head, connecting rod, crankshaft balancer, and main bearing cap bolts now apply a torque angle strategy.

•	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.

•	Refer to Fastener Tightening Specifications and Thread Repair Specifications .

New Sealants and/or Adhesives

Canadian SPO Part Numbers have been added.

Disassembly and Assembly Procedure Revisions

•	The piston, pin, and connecting rod are to be serviced as an assembly.

•	Newer design pistons have a graphite coated piston skirt. The coated skirt outside diameter (OD) may be slightly larger than the cylinder bore inside diameter (ID) and the piston assembly may have a slight interference fit to the cylinder bore during initial installation.

Changed Engine Specifications

Engine specification tables content and format have been commonized.

Disassembly and Assembly Procedure Revisions

•	For certain applications, a spacer plate has been added between the flywheel and rear of the crankshaft. It is necessary to remove the spacer plate prior to removal and installation of the crankshaft rear oil seal and clutch pilot bearing.

•	An exhaust gas recirculation (EGR) system is used on limited applications.

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 Strategy Based Diagnosis in General Information or Diagnostic Starting Point - Engine Mechanical .

New Special Tools Required

•	A variety of new tools have been developed to assist in engine disassembly, assembly, and on-vehicle service.

•	J 43690 and J 43690-100 have been developed to measure connecting rod bearing clearances. Refer to Crankshaft and Bearing Cleaning and Inspection .

•	A cylinder head leakage test, using J 35667-A , has been developed. Refer to Cylinder Leakage Test .

•	J 45299 has been developed to prelube new or remanufactured engines/bearings prior to engine installation. Refer to Engine Prelubing .

•	Refer to Special Tools .

A Component Comparison from the Previous Year

•	All applications will use a two-point engine coolant air bleed pipe design.

•	All applications use the PF44 short length oil filter.

•	The EGR system has been deleted on certain applications.

•	A spacer plate between the crankshaft and flywheel is required for applications using the 4L80-E transmission.

•	All 2003 applications use a piston with a graphite coated skirt.