Home ReviewsRefund
Home/GMC/Sierra 2500/GMC Sierra 2500 (2000-2004)/Repair manual/Mechanical/Engine Mechanical - 4.3L (Unit Repair): Specifications
Contents Wiring diagrams Section: Mechanical All sections

Engine Mechanical - 4.3L (Unit Repair): Specifications GMC Sierra 2500

Mechanical 14 illustrations ~470 words

Fastener Tightening Specifications

ApplicationSpecification
MetricEnglish
Accelerator Control Cable Bracket Nut to Stud12 N.m106 lb in
Accelerator Control Cable Bracket Nut to Throttle Body9 N.m80 lb in
Accelerator Control Cable Bracket Stud to Intake Manifold6 N.m53 lb in
Accelerator Control Cable Bracket Stud to Throttle Body12 N.m106 lb in
Air Cleaner Adapter Stud8 N.m71 lb in
Balance Shaft Driven Gear Bolt
First Pass20 N.m15 lb ft
Final Pass35 degrees
Balance Shaft Retainer Bolt12 N.m106 lb in
Battery Cable Bracket Bolt to Oil Pan12 N.m106 lb in
Battery Negative Cable Bolt to Engine25 N.m18 lb ft
Battery Positive Cable Junction Block Bracket Bolt25 N.m18 lb ft
Belt Idler Pulley Bolt50 N.m37 lb ft
Camshaft Retainer Bolt12 N.m106 lb in
Camshaft Sprocket Bolt25 N.m18 lb ft
Connecting Rod Nut
First Pass27 N.m20 lb ft
Final Pass70 degrees
Crankshaft Balancer Bolt95 N.m70 lb ft
Crankshaft Bearing Cap Bolt - Preferred Method
First Pass20 N.m15 lb ft
Final Pass73 degrees
Crankshaft Bearing Cap Bolt105 N.m77 lb ft
Crankshaft Position Sensor Bolt9 N.m80 lb in
Crankshaft Pulley Bolt58 N.m43 lb ft
Crankshaft Rear Oil Seal Housing Bolt and Nut12 N.m106 lb in
Crankshaft Rear Oil Seal Housing Retainer Stud6 N.m53 lb in
Cylinder Head Bolt - Preferred Method
All Bolts First Pass in Sequence30 N.m22 lb ft
Long Bolts Final Pass in Sequence75 degrees
Medium Bolts Final Pass in Sequence65 degrees
Short Bolts Final Pass in Sequence55 degrees
Cylinder Head Core Hole Plug20 N.m15 lb ft
Distributor Cap Bolt2.4 N.m21 lb in
Distributor Clamp Bolt25 N.m18 lb ft
Drive Belt Tensioner Bolt50 N.m37 lb ft
EGR Valve Bolt
First Pass7 N.m62 lb in
Final Pass30 N.m22 lb ft
EGR Valve Inlet Pipe Clamp Bolt25 N.m18 lb ft
EGR Valve Inlet Pipe Nut at Intake Manifold25 N.m18 lb ft
EGR Valve Inlet Pipe Nut at Exhaust Manifold30 N.m22 lb ft
Engine Block Left Side Oil Gallery Plug20 N.m15 lb ft
Engine Block Left Rear Oil Gallery Plug30 N.m22 lb ft
Engine Block Right Rear Oil Gallery Plug20 N.m15 lb ft
Engine Block Coolant Drain Hole Plug20 N.m15 lb ft
Engine Block Oil Gallery Plug20 N.m15 lb ft
Engine Coolant Heater Bolt/Screw2 N.m18 lb in
Engine Coolant Temperature (ECT) Sensor20 N.m15 lb ft
Engine Flywheel Bolt100 N.m74 lb ft
Engine Front Cover Bolt12 N.m106 lb in
Engine Lift Front Bracket Stud35 N.m26 lb ft
Engine Mount Bolt to Engine Bracket50 N.m37 lb ft
Engine Mount Engine Bracket Bolt to Engine50 N.m37 lb ft
Engine Mount Frame Bracket Through-bolt75 N.m55 lb ft
Engine Mount Frame Side Mount Bolt65 N.m50 lb ft
Engine Oil Level Sensor13 N.m115 lb in
Engine Oil Pressure Gage Sensor30 N.m22 lb ft
Engine Oil Pressure Gage Sensor Fitting - Plus Required Angle15 N.m11 lb ft
Engine Wiring Harness Bracket Bolt to Battery Positive Cable Junction Block Bracket9 N.m80 lb in
Engine Wiring Harness Bracket Bolt to Generator and Drive Belt Tensioner Bracket25 N.m18 lb ft
Engine Wiring Harness Bracket Bolt to Rear Right Side Cylinder Head25 N.m18 lb ft
Engine Wiring Harness Bracket Nut to Evaporative Emission (EVAP) Canister Purge Solenoid Valve Stud9 N.m80 lb in
Engine Wiring Harness Bracket Nut to Intake Manifold Stud12 N.m106 lb in
Evaporative Emission (EVAP) Canister Purge Solenoid Valve Stud to Intake Manifold10 N.m89 lb in
Exhaust Manifold Bolt/Stud
First Pass15 N.m11 lb ft
Final Pass30 N.m22 lb ft
Exhaust Manifold Heat Shield Bolt9 N.m80 lb in
Fan and Water Pump Pulley Bolt25 N.m18 lb ft
Frame Cross Bar Bolt100 N.m74 lb ft
Fuel Meter Body Bracket Bolt10 N.m89 lb in
Fuel Pipe Bracket Bolt6 N.m53 lb in
Fuel Pipe Retainer Nut3 N.m27 lb in
Fuel Supply Pipe Nut - Fuel Tank Side30 N.m22 lb ft
Generator and Drive Belt Tensioner Bracket Bolt to Engine41 N.m30 lb ft
Generator and Drive Belt Tensioner Bracket Stud to Engine20 N.m15 lb ft
Generator and Drive Belt Tensioner Bracket Stud Nut41 N.m30 lb ft
Ground Wire Bolt to Rear of Left Side Cylinder Head16 N.m12 lb ft
Ground Wire Nut to Rear of Right Side Cylinder Head16 N.m12 lb ft
Heater Hose Bracket Bolt to Generator and Drive Belt Tensioner Bracket25 N.m18 lb ft
Ignition Coil Stud12 N.m106 lb in
Knock Sensor25 N.m18 lb ft
Lower Intake Manifold Bolt
First Pass in Sequence3 N.m27 lb in
Second Pass in Sequence12 N.m106 lb in
Final Pass in Sequence15 N.m11 lb ft
Oil Cooler Pipe Bracket to Oil Pan Bolt12 N.m106 lb in
Oil Filter Fitting55 N.m41 lb ft
Oil Level Indicator Tube Bolt12 N.m106 lb in
Oil Pan Baffle Bolt12 N.m106 lb in
Oil Pan Bolt and Nut25 N.m18 lb ft
Oil Pan Drain Plug25 N.m18 lb ft
Oil Pan Skid Plate Bolt20 N.m15 lb ft
Oil Pump Bolt to Rear Crankshaft Bearing Cap90 N.m66 lb ft
Oil Pump Cover Bolt12 N.m106 lb in
Power Steering Pump Bracket Bolt to Engine41 N.m30 lb ft
Power Steering Pump Bracket Stud to Engine20 N.m15 lb ft
Power Steering Pump Bracket Stud Nut41 N.m30 lb ft
Power Steering Pump Bolt50 N.m37 lb ft
Power Steering Pump Nut to Engine - Rear Bracket to Engine41 N.m30 lb ft
Power Steering Pump Rear Bracket Nut50 N.m37 lb ft
Secondary Air Injection (AIR) Check Valve Pipe Bracket Bolt to Exhaust Manifold10 N.m89 lb in
Secondary Air Injection (AIR) Check Valve Pipe Stud Nut25 N.m18 lb ft
Spark Plug
Initial Installation - NEW Cylinder Head30 N.m22 lb ft
All Subsequent Installations15 N.m11 lb ft
Spark Plug Wire Support Bolt12 N.m106 lb in
Starter Motor Wiring Harness/Transmission Cooler Pipe Bracket to Oil Pan Bolt9 N.m80 lb in
Throttle Body Stud9 N.m80 lb in
Transmission to Oil Pan Bolt47 N.m35 lb ft
Transmission Cover Bolt12 N.m106 lb in
Upper Intake Manifold Stud
First Pass5 N.m44 lb in
Final Pass9 N.m80 lb in
Valve Lifter Pushrod Guide Bolt16 N.m12 lb ft
Valve Rocker Arm Bolt30 N.m22 lb ft
Valve Rocker Arm Cover Bolt12 N.m106 lb in
Water Outlet Stud25 N.m18 lb ft
Water Pump Bolt45 N.m33 lb ft

FASTENER TIGHTENING SPECIFICATIONS

Engine Mechanical Specifications

ApplicationSpecification
MetricEnglish
General Data
Engine TypeV6
RPO CodeL35/LU3
VIN CodeW/X
Displacement4.3 L262 CID
Bore101.60 mm4.012 in
Stroke88.39 mm3.480 in
Compression Ratio9.2:1
Firing Order1-6-5-4-3-2
Spark Plug Gap1.52 mm0.060 in
42 kPa at 1,000 RPM6 psig at 1,000 RPM
Oil Pressure - Minimum - at Normal Operating Temperature125 kPa at 2,000 RPM18 psig at 2,000 RPM
166 kPa at 4,000 RPM24 psig at 4,000 RPM
Balance Shaft
Rear Bearing Journal Clearance0.050-0.088 mm0.0020-0.0035 in
Rear Bearing Journal Diameter38.085-38.100 mm1.4994-1.500 in
Camshaft
End Play0.0254-0.2286 mm0.0010-0.0090 in
Journal Diameter47.440-47.490 mm1.8677-1.8696 in
Journal Diameter Out-of-Round0.025 mm - Maximum0.0010 in - Maximum
Lobe Lift - Exhaust7.20-7.30 mm0.283-0.287 in
Lobe Lift - Intake6.97-7.07 mm0.274-0.278 in
Runout0.065 mm0.0026 in
Connecting Rod
Connecting Rod Bearing Clearance - Production0.038-0.078 mm0.0015-0.0031 in
Connecting Rod Bearing Clearance - Service0.025-0.063 mm0.0010-0.0025 in
Connecting Rod Journal Diameter57.116-57.148 mm2.2487-2.2497 in
Connecting Rod Journal Out-of-Round - Production0.007 mm - Maximum0.0002 in - Maximum
Connecting Rod Journal Out-of-Round - Service0.025 mm - Maximum0.0010 in - Maximum
Connecting Rod Journal Taper - Production0.00508 mm - Maximum0.00030 in - Maximum
Connecting Rod Journal Taper - Service0.025 mm - Maximum0.0010 in - Maximum
Connecting Rod Side Clearance0.15-0.44 mm0.006-0.017 in
Crankshaft
Crankshaft Bearing Clearance - Journal #1-Production0.02-0.508 mm0.0008-0.0020 in
Crankshaft Bearing Clearance - Journal #2, #3, and #4-Production0.028-0.058 mm0.0011-0.0023 in
Crankshaft Bearing Clearance - Journal #1-Service0.0254-0.05 mm0.0010-0.0020 in
Crankshaft Bearing Clearance - Journal #2, #3, and #4-Service0.025-0.063 mm0.0010-0.0250 in
Crankshaft End Play0.050-0.20 mm0.002-0.008 in
Crankshaft Journal Diameter - Journal #162.199-62.217 mm2.4488-2.4495 in
Crankshaft Journal Diameter - Journal #2 and #362.191-62.215 mm2.4485-2.4494 in
Crankshaft Journal Diameter - Journal #462.179-62.203 mm2.4480-2.4489 in
Crankshaft Journal Out-of-Round - Production0.005 mm - Maximum0.0002 in - Maximum
Crankshaft Journal Out-of-Round - Service0.025 mm - Maximum0.0010 in - Maximum
Crankshaft Journal Taper - Production0.007 mm - Maximum0.0003 in - Maximum
Crankshaft Runout0.025 mm - Maximum0.0010 in - Maximum
Cylinder Bore
Diameter101.618-101.643 mm4.0007-4.0017 in
Out-of-Round - Production0.0127 mm - Maximum0.00050 in - Maximum
Out-of-Round - Service0.05 mm - Maximum0.002 in - Maximum
Taper - Production Relief Side0.025 mm - Maximum0.0010 in - Maximum
Taper - Production Thrust Side0.012 mm - Maximum0.0005 in - Maximum
Taper - Service0.025 mm - Maximum0.0010 in - Maximum
Cylinder Head
Surface Flatness0.10 mm - Maximum0.004 in - Maximum
Exhaust Manifold
Surface Flatness - Flange to Flange0.25 mm - Maximum0.010 in - Maximum
Surface Flatness - Individual Flange0.05 mm - Maximum0.002 in - Maximum
Intake Manifold
Surface Flatness0.10 mm - Maximum0.004 in - Maximum
Oil Pan
Oil Pan Alignment at Rear of Engine Block0.3 mm - Maximum0.011 in - Maximum
Piston
Piston Bore Clearance - Production0.018-0.061 mm0.0007-0.0024 in
Piston Bore Clearance - Service0.075 mm - Maximum0.0029 in - Maximum
Piston Pin
Clearance in Piston - Production0.013-0.023 mm0.0005-0.0009 in
Clearance in Piston - Service0.025 mm - Maximum 0.0010 in - Maximum
Diameter23.545-23.548 mm0.9270-0.9271 in
Fit in Connecting Rod0.012-0.048 mm - Interference0.0005-0.0019 in - Interference
Piston Rings - End Gap Measured in Cylinder Bore
Piston Compression Ring Gap - Production-Top Groove0.25-0.40 mm0.010-0.016 in
Piston Compression Ring Gap - Production-2nd Groove0.38-0.58 mm0015-0.023 in
Piston Compression Ring Gap - Service-Top Groove0.25-0.50 mm0.010-0.020 in
Piston Compression Ring Gap - Service-2nd Groove0.38-0.80 mm0.015-0.031 in
Piston Compression Ring Groove Clearance - Production-Top Groove0.030-0.070 mm0.0012-0.0027 in
Piston Compression Ring Groove Clearance - Production-2nd Groove0.040-0.080 mm0.0015-0.0031 in
Piston Compression Ring Groove Clearance - Service0.030-0.085 mm0.0012-0.0033 in
Piston Oil Ring Gap - Production0.25-0.76 mm0.010-0.029 in
Piston Oil Ring Gap - Service0.005-0.090 mm0.0002-0.0035 in
Piston Oil Ring Groove Clearance - Production0.046-0.196 mm0.0018-0.0077 in
Piston Oil Ring Groove Clearance - Service0.046-0.200 mm0.0018-0.0079 in
Valve System
Valve Face Angle45 degrees
Valve Head Edge Margin0.79 mm - Minimum0.031 in - Minimum
Valve LashNet Lash-No Adjustment
Valve Lift - Exhaust10.879 mm0.4280 in
Valve Lift - Intake10.527 mm0.4140 in
Valve LifterHydraulic Roller Type
Valve Rocker ArmRoller Pivot Type
Valve Rocker Arm Ratio1.5:1
Valve Seat Angle46 degrees
Valve Seat Runout0.05 mm - Maximum0.002 in - Maximum
Valve Seat Width - Exhaust1.651-2.489 mm0.065-0.098 in
Valve Seat Width - Intake1.016-1.651 mm0.040-0.065 in
Valve Spring Free Length51.3 mm2.02 in
Valve Spring Installed Height - Exhaust42.92-43.43 mm1.670-1.700 in
Valve Spring Installed Height - Intake42.92-43.43 mm1.670-1.700 in
Valve Spring Pressure - Closed338-374 N at 43.2 mm76-84 lb at 1.70 in
Valve Spring Pressure - Open832-903 N at 32.3 mm187-203 lb at 1.27 in
Valve Stem Clearance - Exhaust-Production0.025-0.069 mm0.0010-0.0027 in
Valve Stem Clearance - Exhaust-Service0.025-0.094 mm0.0010-0.0037 in
Valve Stem Clearance - Intake-Production0.025-0.069 mm0.0010-0.0027 in
Valve Stem Clearance - Intake-Service0.025-0.094 mm0.0010-0.0037 in
Valve Stem Oil Seal Installed Height - Measured from the Top of the Large Diameter Valve Guide Bevel to the Bottom of the Valve Stem Oil Seal1-2 mm0.03937-0.07874 in

ENGINE MECHANICAL SPECIFICATIONS

Scheme 131

Scheme 131: Sealers, Adhesives & Lubricants
Scheme 131: Sealers, Adhesives & Lubricants

Scheme 132

Scheme 132: Disassembled Views
Scheme 132: Disassembled Views

Scheme 133

Scheme 133
Scheme 133

Scheme 134

Scheme 134
Scheme 134

Scheme 135

Scheme 135
Scheme 135

Scheme 136

Scheme 136
Scheme 136

Scheme 137

Scheme 137: Engine Identification
Scheme 137: Engine Identification

Scheme 138

Scheme 138
Scheme 138

Scheme 139

Scheme 139
Scheme 139
  1. The Vehicle Identification Number (VIN) Derivative is located on the left side rear of the engine block (1) or on the right side rear (2) and typically is a nine digit number stamped or laser etched onto the engine at the vehicle assembly plant. The first digit identifies the division. The second digit identifies the model year. The third digit identifies the assembly plant. The fourth through ninth digits are the last six digits of the Vehicle Identification Number (VIN).
  2. Engines built at the Tonawanda engine plant have the engine identification number located at the right front top of the engine block. The first digit (1) is the source code. The second and third digits (2) are the month of build. The forth and fifth digits (3) are the date of build. The sixth, seventh, and eighth digits (4) are the broadcast code.
  3. Engines built at the Romulus engine plant have the engine identification number located at the right front top of the engine block. The first digit (1) is the source code. The second and third digits (2) are the month of build. The fourth digit (3) is the hour of the build. The fifth and sixth digits (4) are the date of build. The seventh, eighth, and ninth digits (5) are the broadcast code.

Scheme 140

Scheme 140: Draining Fluids & Oil Filter Removal
Scheme 140: Draining Fluids & Oil Filter Removal

Scheme 141

Scheme 141
Scheme 141

Scheme 142

Scheme 142
Scheme 142
  1. Remove the oil pan drain plug and allow the engine oil to drain into a suitable container.
  2. Remove the oil filter, if applicable.
  3. Discard the oil filter, if applicable.
  4. Remove both the engine block coolant drain hole plugs and allow the coolant to drain into a suitable container.

Scheme 143

Scheme 143: Engine Flywheel Removal
Scheme 143: Engine Flywheel Removal

Scheme 144

Scheme 144
Scheme 144
  1. Remove the engine flywheel bolts.
  2. Remove the engine flywheel (1), automatic transmission, if applicable.
  3. Remove the engine flywheel (2), manual transmission, if applicable. Important: If replacing the engine flywheel, manual transmission, NEW flywheel weights must be installed into the NEW engine flywheel in the same location as the old flywheel weights in the old engine flywheel.
  4. Note the position of any flywheel weights for assembly, if applicable.

Torque Values and/or Fastener Tightening Strategies

  1. Cylinder head bolts, the crankshaft bearing cap bolts, the connecting rod bolts, and balance shaft bolt apply a torque angle strategy.

In an on-vehicle situation where a torque angle meter may not fit into the vehicle packaging, a three step tightening process may be followed using a torque wrench.

  1. Certain fasteners should not be reused. Bolts, studs, or other fasteners that must be replaced will be called out in the specific service procedure.

Changed Engine Specifications

Engine mechanical specifications remain the same as the 2001 products.

More articles — Engine Mechanical - 4.3L (Unit Repair)