Engine Mechanical - 4.3L: Other Chevrolet Silverado 2500 HD

Sealers, Adhesives, and Lubricants

Sealers, Adhesives, and Lubricants

Scheme 35

Scheme 36

Scheme 37

Scheme 38

Scheme 39

Intermittent

Test the vehicle under the same conditions that the customer reported in order to verify the system is operating properly.

Base Engine Misfire without Internal Engine Noises

Base Engine Misfire without Internal Engine Noises

Base Engine Misfire with Abnormal Internal Lower Engine Noises

Base Engine Misfire with Abnormal Internal Lower Engine Noises

Base Engine Misfire with Coolant Consumption

Base Engine Misfire with Coolant Consumption

Base Engine Misfire with Excessive Oil Consumption

Base Engine Misfire with Excessive Oil Consumption

Engine Will Not Crank - Crankshaft Will Not Rotate

Engine Will Not Crank - Crankshaft Will Not Rotate

Coolant in Combustion Chamber

Coolant in Combustion Chamber

Coolant in Engine Oil

Coolant in Engine Oil

Tools Required

J 35667-A Cylinder Head Leakdown Tester. See Special Tools .

With the use of air pressure, a cylinder leakage test will aid in the diagnosis. Use the cylinder leakage test in conjunction with the engine compression test in order to isolate the cause of leaking cylinders.

1. Disconnect the battery ground negative cable.
2. Remove the spark plugs. Refer to «Spark Plug Replacement»(ref-278028-S37384053562008012100000) use for the 4.3L engine.
3. Rotate the crankshaft to place the piston in the cylinder being tested at top dead center (TDC) of the compression stroke, with both valves closed.
4. Install the J 35667-A . See «Special Tools»(ref-278083-S19118114702008012100000) .
5. Apply shop air pressure to the J 35667-A and adjust according to the manufacturer instructions. See «Special Tools»(ref-278083-S19118114702008012100000) .
6. Record the cylinder leakage value. Cylinder leakage that exceeds 25 percent is considered excessive and may require component service. In excessive leakage situations, inspect for the following conditions: Air leakage from the intake or exhaust system may indicate a worn or burnt valve or a broken valve spring. Remove the valve rocker arm cover of the suspect cylinder head. Refer to «Valve Rocker Arm Cover Replacement - Left Side»(ref-278083-S17905806892008012100000) or «Valve Rocker Arm Cover Replacement - Right Side»(ref-278083-S07028108132008012100000) . Ensure that both valves are closed. Inspect the cylinder head for a broken valve spring. Remove and inspect the suspect cylinder head. Refer to «Cylinder Head Replacement - Left Side»(ref-278083-S34375698502008012100000) or «Cylinder Head Replacement - Right Side»(ref-278083-S14270605802008012100000) . Air leakage from the crankcase, oil level indicator, or oil fill tube may indicate worn piston rings, a damaged piston, a worn or scored cylinder bore, a damaged engine block or a damaged cylinder head. Remove the piston from the suspect cylinder. Refer to «Piston, Connecting Rod, and Bearing Removal»(ref-278083-S02455644492008012100000) or «Piston, Connecting Rod, and Bearing Installation»(ref-278083-S38125776372008012100000) . Inspect the piston and connecting rod assembly. Refer to «Piston, Connecting Rod, and Bearing Cleaning and Inspection»(ref-278083-S38313597722008012100000) . Inspect the engine block. Refer to «Engine Block Cleaning and Inspection»(ref-278083-S35119226712008012100000) . Inspect the cylinder head. Refer to «Cylinder Head Cleaning and Inspection»(ref-278083-S12123661622008012100000) . Air bubbles in the cooling system may indicate a damaged cylinder head or a damaged cylinder head gasket. Remove both cylinder heads. Refer to «Cylinder Head Replacement - Left Side»(ref-278083-S34375698502008012100000) or «Cylinder Head Replacement - Right Side»(ref-278083-S14270605802008012100000) . Inspect both cylinder heads. Refer to «Cylinder Head Cleaning and Inspection»(ref-278083-S12123661622008012100000) . Inspect the engine block. Refer to «Engine Block Cleaning and Inspection»(ref-278083-S35119226712008012100000) .
7. Remove the J 35667-A . See «Special Tools»(ref-278083-S19118114702008012100000) .
8. Install the spark plugs. Refer to «Spark Plug Replacement»(ref-278028-S37384053562008012100000) use for the 4.3L engine.
9. Connect the battery ground negative cable.

Functional Check

With these systems, any blow-by in excess of the system capacity, from a badly worn engine, sustained heavy load, etc., is exhausted into the air cleaner and is drawn into the engine.

Proper operation of the crankcase ventilation system depends upon a sealed engine. If oil slugging or dilution is noted and the crankcase ventilation system is functioning properly, check the engine for a possible cause. Correct any problems.

If an engine is idling rough, inspect for a clogged PCV orifice, a dirty vent filter, air cleaner element, or plugged hose. Replace as required. Use the following procedure

1. Remove the PCV hose from the rocker arm cover.
2. Operate the engine at idle.
3. Place your thumb over the end of the hose in order to check for a vacuum. If there is no vacuum at the hose, inspect for the following items: Plugged hoses The manifold port
4. Turn OFF the engine.
5. Inspect the PCV orifice in the valve cover for debris or blockage.

J 3049-A Valve Lifter Remover. See Special Tools .

J 45059 Angle Meter. See Special Tools .

J 45059 Angle Meter. See Special Tools .

J 23523-F Crankshaft Balancer Remover and Installer. See Special Tools .

J 35468 Cover Aligner and Seal Installer. See Special Tools .

J 5590 Rear Pinion Bearing Race Installer. See Special Tools .

J 5590 Rear Pinion Bearing Race Installer. See Special Tools .

J 41712 Oil Pressure Switch Socket. See Special Tools .

J 35621-B Rear Main Seal Installer. See Special Tools .

J 41427 Engine Lift Brackets

J 43276 Clutch Pilot Bearing Remover. See Special Tools .

1. Remove the clutch pilot bearing using the J 43276 . See «Special Tools»(ref-278083-S19118114702008012100000) . Install the J 43276-1 tool body into the clutch pilot bearing. Using a wrench secure the J 43276-1 tool body. Insert the J 43276-2 forcing screw into the J 43276-1 tool body. Rotate the J 43276-2 forcing screw clockwise into the J 43276-1 tool body until the clutch pilot bearing is completely removed from the crankshaft. Rotate the J 43276-2 forcing screw counterclockwise to remove the J 43276-2 forcing screw from the J 43276-1 tool body. Remove the J 43276-1 tool body from the clutch pilot bearing.
2. Discard the clutch pilot bearing.

J 41240 Fan Clutch Remover and Installer. See Special Tools .

1. Remove the bolts and the fan and water pump pulley using the J 41240 . See «Special Tools»(ref-278083-S19118114702008012100000) .
2. Remove the clamps and the water pump inlet hose.
3. Remove the water pump bolts.
4. Remove the water pump.
5. Remove the water pump gaskets.
6. Discard the water pump gaskets.

J 23523-F Balancer Remover and Installer

1. Remove the crankshaft balancer bolt and washer.
2. Remove the bolts and the crankshaft pulley.
3. Use the J 23523-F in order to remove the crankshaft balancer. Install the J 23523-F plate and bolts onto the crankshaft balancer. Tighten: Tighten the bolts to 25 N.m (18 lb ft). Install the J 23523-F forcing screw into the plate. Rotate the J 23523-F forcing screw clockwise in order to remove the crankshaft balancer.
4. Remove the J 23523-F from the crankshaft balancer.
5. Note the position and length of any crankshaft balancer front groove pins, if applicable.

J 3049-A Valve Lifter Remover. See Special Tools .

1. Remove the bolts and valve lifter pushrod guide.
2. Remove the valve lifters.
3. Use the J 3049-A in order to remove the stuck valve lifters. See «Special Tools»(ref-278083-S19118114702008012100000) .

J 5825-A Crankshaft Gear Remover. See Special Tools .

1. Remove the crankshaft position sensor reluctor ring.
2. Remove the timing chain tensioner shoe (229) using a downward motion.
3. Remove the timing chain tensioner bracket bolt and bracket (227 and 228).
4. Check the camshaft timing chain free play. Rotate the camshaft sprocket (1) counterclockwise until all slack is removed from the camshaft timing chain (2). Measure the free play on the slack side (3) of the camshaft timing chain. If the camshaft timing chain can be moved side to side in excess of 11 mm (0.43 in), replacement of the camshaft timing chain and the sprockets is recommended during assembly.
5. Remove the camshaft sprocket bolts.
6. Remove the camshaft sprocket and the camshaft timing chain.
7. Remove the crankshaft sprocket using the J 5825-A . See «Special Tools»(ref-278083-S19118114702008012100000) .
8. Remove the crankshaft balancer key.

J 24270 Cylinder Bore Ridge Reamer. See Special Tools .

1. Use the J 24270 in order to remove the cylinder ring ridge. See «Special Tools»(ref-278083-S19118114702008012100000) . Turn the crankshaft until the piston is at the bottom of the stroke. Place a cloth on top of the piston. Use the J 24270 to remove all of the cylinder ring ridge. See «Special Tools»(ref-278083-S19118114702008012100000) . Turn the crankshaft so the piston is at the top of the stroke. Remove the cloth. Remove the cutting debris.
2. Remove the connecting rod bolts, cap, and bearing.
3. Remove the connecting rod and the piston out of the top of the engine block.
4. Remove the connecting rod bearings from the connecting rod. Keep all connecting rod bearings and rod bearing caps with the original connecting rods, and in the original orientation at the connecting rod/rod bearing cap mating area. Wipe the oil from the connecting rod bearings. Wipe the oil from the crankpins.

J 41712 Oil Pressure Switch Socket. See Special Tools .

1. Remove the knock sensor retaining bolt (1).
2. Remove the knock sensor (2).
3. Remove the engine oil pressure gage sensor using the J 41712 . See «Special Tools»(ref-278083-S19118114702008012100000) .
4. Remove the engine oil pressure sensor fitting.
5. Remove the transmission locator dowel straight pins, if required.
6. Remove the engine block left side oil gallery plug.
7. Remove the engine block left rear oil gallery plug.
8. Remove the engine block right rear oil gallery plug.
9. Remove the expansion cup plug from the camshaft rear bearing hole and discard.
10. Remove the expansion cup plug from the balance shaft rear bearing hole and discard.
11. Remove the crankshaft rear oil seal housing locator spring type S pin, if required.
12. Remove the front oil gallery plugs or balls from the front of the engine block and discard. Insert a 3/8 x 26 inch rod into the rear oil gallery holes in order to drive out the front oil gallery plugs or balls.
13. Remove the engine block core hole plugs. Use a suitable tool in order to drive the engine block core hole plugs into the coolant jacket. Use a suitable tool in order to pull the engine block core hole plugs from the coolant jacket. Discard the engine block core hole plugs.
14. Remove the oil filter bypass valve and discard.

J 8087 Cylinder Bore Gage

1. Clean all the remaining sealing or gasket material from the sealing surfaces.
2. Clean the engine block with cleaning solvent.
3. Flush the engine block with clean water or steam.
4. Clean the cylinder bores.
5. Clean the oil galleries and the oil passages.
6. Clean the scale and the deposits from the coolant passages.
7. Clean the engine block cylinder head bolt holes.
8. After cleaning the engine block, spray or wipe the cylinder bores and the machined surfaces with clean engine oil.
9. Inspect the following areas: Coolant jackets (1) for cracks Cylinder bores (2) for scratches or gouging Valve lifter bores (3) for excessive scoring or wear Threaded holes (4) for damage Crankshaft bearing webs (5) for cracks Crankshaft bearing caps (6) and the crankshaft bearing bores (7) for damage The crankshaft bearing bores should be round and uniform when measuring the inside diameter (ID). The surface where the crankshaft bearings contact the crankshaft bearing bore should be smooth. If a crankshaft bearing cap is damaged and requires replacement, replace the crankshaft bearing cap first, then rebore the engine block crankshaft bearing bores and check for the proper alignment. Finally, check the crankshaft for the proper clearances. Engine block core hole plug bores (8) for damage Engine block (9) for cracks or damage Engine mount bosses (10) for damage
10. Measure the cylinder bores for taper and out-of-round. Depress the plunger on the J 8087 to 7 mm (0.275 in) or until the J 8087 enters the cylinder bore. Center the J 8087 in the cylinder bore and turn the indicator dial to 0. Move the J 8087 up and down the cylinder bore to determine the cylinder bore taper. Refer to «Engine Mechanical Specifications»(ref-278083-S33878724872008012100000) . Turn the J 8087 to different points around the cylinder bore to determine the cylinder bore out-of-round condition. Refer to «Engine Mechanical Specifications»(ref-278083-S33878724872008012100000) .

Honing Procedure

1. When honing the cylinder bores, follow the manufacturer's recommendations for equipment use, cleaning, and lubrication. Use only clean sharp stones of the proper grade for the amount of material to be removed. Dull, dirty stones cut unevenly and generate excessive heat. DO NOT hone to a final grade with a coarse or medium-grade stone. Leave sufficient metal so that all the stone marks will be removed with the fine grade stones. Perform the final honing with a fine-grade stone and hone the cylinder bore in a cross hatch pattern at 45-65 degrees to obtain the proper clearance.
2. During the honing operation, thoroughly check the cylinder bore. Repeatedly check the cylinder bore fit with the selected piston. All measurements of the piston or cylinder bore should be made with the components at normal room temperature.
3. When honing to eliminate taper in the cylinder bore, use full strokes the complete length of the cylinder bore. Repeatedly check the measurement at the top, the middle, and the bottom of the cylinder bore. The finish marks should be clean but not sharp. The finish marks should be free from imbedded particles or torn or folded metal.
4. When finished, the reconditioned cylinder bores should have less than or meet the specified out-of-round and taper requirements.
5. After the final honing and before the piston is checked for fit, clean the cylinder bore with hot water and detergent. Scrub the cylinder bores with a stiff bristle brush. Rinse the cylinder bores thoroughly with clean hot water. Dry the cylinder bores with a clean rag. Do not allow any abrasive material to remain in the cylinder bores. Abrasive material may cause premature wear of the new piston rings and the cylinder bores. Abrasive material will contaminate the engine oil and may cause premature wear of the bearings.
6. Perform final measurements of the piston and the cylinder bore.
7. Permanently mark the top of the piston for the specified cylinder to which it has been fitted.
8. Apply clean engine oil to each cylinder bore in order to prevent rusting.

Boring Procedure

1. Before starting the honing or reboring operation, measure all the new pistons with the micrometer contacting at points exactly 90 degrees from the piston pin centerline.
2. File the top of the cylinder block in order to remove any dirt or burrs before using any type of boring bar.
3. Follow the instructions furnished by the manufacturer regarding use of the boring equipment.
4. When reboring the cylinders, make sure all the crankshaft bearing caps are installed in the original position and direction.
5. Tighten the crankshaft bearing caps to the proper torque specifications in order to avoid distortion of the cylinder bores in the final assembly.
6. When making the final cut with the boring bar, leave 0.03 mm (0.001 in) on the cylinder bore diameter for finish honing. This gives the required position to the cylinder clearance specifications. Carefully perform the honing and boring operation in order to maintain the specified clearances between the pistons, the piston rings, and the cylinder bores.

J 24086-C Piston Pin Remover/Installer. See Special Tools .

1. Remove the piston rings from the pistons.
2. Press the piston pin from the connecting rod using the J 24086-C . See «Special Tools»(ref-278083-S19118114702008012100000) . The piston pin has an interference fit into the connecting rod, and is full floating in the piston.
3. Mark, separate, and organize the parts for assembly.

J 24086-C Piston Pin Remover/Installer. See Special Tools .

1. Install the new piston pin and connecting rod assembly. Lubricate the piston pin bores with clean engine oil. Use a torch and apply MILD heat to the piston pin end of the connecting rod. Use the J 24086-C in order to press the new piston pin into the piston and connecting rod assembly. See «Special Tools»(ref-278083-S19118114702008012100000) . Inspect for the proper installation of the piston and piston pin. The piston must move freely on the new piston pin with no binding or interference.
2. Install the piston rings onto the piston. Install the oil control piston ring spacer. Install the lower oil control piston ring. Install the upper oil control piston ring. Install the lower compression piston ring. The mark on the side of the piston ring should face the top of the piston. Install the upper compression piston ring. The mark on the side of the piston ring should face the top of the piston.
3. Space the compression piston ring end gaps 120 degrees apart.
4. Space the oil control piston ring end gaps a minimum of 90 degrees apart.

Measuring Crankshaft Bearing Clearances

1. The crankshaft bearings are of the precision insert type and do not use shims for adjustment. If the clearances are excessive, then new upper and lower crankshaft bearings will be required. The service crankshaft bearings are available in the standard size and an undersize.
2. The selective fitting of the crankshaft bearings are necessary in production in order to obtain close tolerances. For this reason, in one journal bore you may use one-half of a standard crankshaft bearing with one-half of an undersize crankshaft bearing.
3. In order to determine the correct replacement bearing size, the bearing clearance must be measured accurately. When checking main bearing clearances, either the micrometer or plastic gage method may be used; however, the micrometer method gives more reliable results and is preferred. When checking connecting rod bearing clearances, the plastic gage method will result in unreliable measurements. The use of J 43690 is preferred. See «Special Tools»(ref-278083-S19118114702008012100000) .
4. Normally the crankshaft bearing journals wear evenly and are not out-of-round. However, if a crankshaft bearing is being fitted to an out-of-round crankshaft bearing journal, be sure to fit to the maximum diameter of the crankshaft bearing journal. If the crankshaft bearing is fitted to the minimum diameter and the crankshaft bearing journal is excessively out-of-round, the interference between the crankshaft bearing and the crankshaft bearing journal will result in rapid crankshaft bearing failure.
5. If the crankshaft bearing clearance is within specifications, the crankshaft bearing is satisfactory. If the clearance is not within specifications, replace the crankshaft bearing. Always replace both the upper and lower crankshaft bearings as a set.
6. A standard or undersize crankshaft bearing combination may result in the proper clearance. If the proper crankshaft bearing clearance cannot be achieved using the standard or the undersize crankshaft bearings, it may be necessary to repair or replace the crankshaft.

Measuring Crankshaft Bearing Clearances - Micrometer Method

1. Measure the crankshaft journal diameter with a micrometer in several places, approximately 90 degrees apart. Average the measurements.
2. Determine the taper and out-of-round of the journal. Refer to «Engine Mechanical Specifications»(ref-278083-S33878724872008012100000) .
3. Install the bearings into the engine block or connecting rod assembly.
4. Install the bearing cap bolts and tighten to specifications. Refer to «Fastener Tightening Specifications»(ref-278083-S36204720082008012100000) .
5. Measure the bearing inside diameter (ID) at two points 90 degrees apart. Average the measurements.
6. In order to determine the bearing clearance, subtract the average journal diameter from the average bearing inside diameter.
7. Compare the readings to specifications. Refer to «Engine Mechanical Specifications»(ref-278083-S33878724872008012100000) .
8. Replace bearing halves as required to obtain the proper bearing clearances.

Measuring Connecting Rod Bearing Clearances - J 43690 Method

1. Remove the oil pan and other necessary components to gain access to the connecting rods. Remove the oil pump assembly.
2. Rotate the crankshaft until the crankshaft journal/connecting rod to be measured is in the 10 o'clock position.
3. Remove the bearing cap bolts, cap and bearing half.
4. Insert a piece of paper card stock onto the crankshaft journal. Install the bearing half, bearing cap, and bolts. Refer to «Fastener Tightening Specifications»(ref-278083-S36204720082008012100000) .
5. Install the foot (1) and bolt (2) to the pivot arm assembly (3). Tighten the bolt until snug.
6. Install the screw (1 or 3) to the pivot arm assembly (2).
7. Install the pivot arm assembly (1) onto the connecting rod.
8. Position the foot of the pivot arm assembly over the large end of the connecting rod bolt.
9. Position the screw (1) onto the small end of the connecting rod bolt and tighten securely.
10. Install the base (1) and bolt (2) to the oil pan rail.
11. Align the center of the base (1) with the screw (3) of the pivot arm assembly. Tighten the bolt (2) until snug.
12. Align the link (1) of the pivot arm assembly on a plane (3) equal to that of the connecting rod beam (2).
13. With the link of the pivot arm assembly aligned to the beam of the connecting rod, position the pivot arm to the base and insert the pin (1).
14. Insert the handle (1) to the pivot arm assembly.
15. Select the adapter (2), as required, and install to the swivel base (1). Tighten until snug.
16. Install the indicator (2) to the swivel base (1). Tighten the clamp of the base until snug.
17. Install the swivel base (1) to the oil pan rail of the engine block. Tighten until snug.
18. Adjust the swivel base as required and position the indicator tip slightly above the connecting rod cap. Lock the swivel base in position by rotating the locking lever (1). Do not allow the tip of the indicator to contact the connecting rod at this time.
19. The tip of the indicator should be positioned above and NOT in contact with the cap end of the connecting rod.
20. Rotate the fine adjustment knobs on the dial indicator end of the swivel base to position the tip of the indicator in contact with the connecting rod.
21. Lightly actuate the handle of the pivot arm assembly, multiple times in both directions, to ensure the oil film is removed from the journal.
22. Load the handle in the forward position and zero the dial indicator. Load the handle multiple times in both directions and record the reading.
23. Remove the bearing cap bolts, cap, and paper stock.
24. Replace bearing halves as required to obtain the proper bearing clearances.
25. Install the bearings, cap, and bolts. Refer to «Fastener Tightening Specifications»(ref-278083-S36204720082008012100000) .

Measuring Crankshaft Bearing Clearances - Plastic Gage Method

1. Install the crankshaft bearings into the engine block.
2. Install the crankshaft.
3. Install the gaging plastic the full width of the journal.
4. Install the crankshaft bearings into the crankshaft bearing caps.
5. Install the crankshaft bearing caps in the original positions and with the arrow on the crankshaft bearing caps in the direction of the front of the engine block.
6. Install the crankshaft bearing cap bolts. Tighten: Tighten the crankshaft bearing caps to 105 N.m (77 lb ft).
7. Remove the crankshaft bearing cap bolts.
8. Remove the crankshaft bearing caps. The gaging plastic may adhere to either the crankshaft bearing journal or the crankshaft bearing surface.
9. Without removing the gaging plastic, measure the compressed width at the widest point using the graduated scale on the edge of the gaging plastic envelope. If the flattened gaging plastic tapers toward the middle or the ends, there may be a difference in clearance indicating taper, low spot or other irregularity of the crankshaft bearing or the crankshaft bearing journal.
10. Remove the flattened gaging plastic.
11. Measure the remaining crankshaft bearing journals.

Measuring Connecting Rod Bearing Side Clearance

1. Insert a feeler gage between the connecting rod caps and measure the connecting rod side clearance. The proper connecting rod side clearance specification is 0.15-0.44 mm (0.006-0.017 in).
2. Connecting rod side clearances may also be measured with a dial indicator set.

J 7872 Magnetic Base Dial Indicator

1. Clean the engine camshaft in cleaning solvent.
2. Dry the engine camshaft with compressed air.
3. Inspect the camshaft retainer plate for damage. If the camshaft retainer plate is damaged, replace as necessary.
4. Inspect the camshaft bearings for correct fit into the engine block camshaft bearing bores. The camshaft bearings have an interference fit to the engine block camshaft bearing bores and must not be loose in the engine block camshaft bearing bores.
5. Inspect the camshaft bearings for excessive wear or scoring.
6. Inspect the engine camshaft for the following: Worn, scored, or damaged bearing journals (1) Worn engine camshaft lobes (2) Damaged bolt hole threads (3) Damaged camshaft sprocket locator pin (4)
7. Measure the engine camshaft journals with a micrometer. If the camshaft journals are more than 0.025 mm (0.0010 in) out-of-round, then replace the engine camshaft.
8. Measure for a bent engine camshaft or excessive engine camshaft runout using the J 7872 . Mount the engine camshaft in a suitable stand between centers. Use the J 7872 in order to check the intermediate engine camshaft journals. If the runout exceeds 0.065 mm (0.0026 in), the engine camshaft is bent and must be replaced.
9. Measure the engine camshaft lobe lift using the J 7872 . Place the engine camshaft on the V-blocks. Use the J 7872 in order to measure the engine camshaft lobe lift.
10. Replace the engine camshaft if the engine camshaft lobe lift is not within specifications. Refer to «Engine Mechanical Specifications»(ref-278083-S33878724872008012100000) .

J 33049 Camshaft Bearing Service Kit. See Special Tools .

1. Select the cone (1), the handle (10), the expanding driver (4-8), the washer (2 or 3), and the expander assembly (15) from the J 33049 . See «Special Tools»(ref-278083-S19118114702008012100000) .
2. Assemble the J 33049 . See «Special Tools»(ref-278083-S19118114702008012100000) .
3. Remove the camshaft inner bearings #2 and #3. Insert the J 33049 through the front of the engine block and into the camshaft inner bearing #2. See «Special Tools»(ref-278083-S19118114702008012100000) . Tighten the J 33049 expander assembly nut until snug. See «Special Tools»(ref-278083-S19118114702008012100000) . Push the J 33049 guide cone into the camshaft front bearing in order to align the J 33049 . See «Special Tools»(ref-278083-S19118114702008012100000) . Drive the camshaft inner bearing #2 from the camshaft inner bearing bore #2. Loosen the J 33049 expander assembly nut. See «Special Tools»(ref-278083-S19118114702008012100000) . Remove the camshaft inner bearing #2 from the J 33049 expander assembly. See «Special Tools»(ref-278083-S19118114702008012100000) . Insert the J 33049 expander assembly into the camshaft inner bearing #3. See «Special Tools»(ref-278083-S19118114702008012100000) . Tighten the J 33049 expander assembly nut until snug. See «Special Tools»(ref-278083-S19118114702008012100000) . Push the J 33049 guide cone into the camshaft front bearing in order to align the J 33049 . See «Special Tools»(ref-278083-S19118114702008012100000) . Drive the camshaft inner bearing #3 from the camshaft inner bearing bore #3. Loosen the J 33049 expander assembly nut. See «Special Tools»(ref-278083-S19118114702008012100000) . Remove the camshaft inner bearing #3 from the J 33049 expander assembly. See «Special Tools»(ref-278083-S19118114702008012100000) .
4. Remove the J 33049 from the engine block. See «Special Tools»(ref-278083-S19118114702008012100000) .
5. Remove the camshaft outer bearings #1 and #4. Insert the J 33049 into the camshaft outer bearing #1. See «Special Tools»(ref-278083-S19118114702008012100000) . Tighten the J 33049 expander assembly nut until snug. See «Special Tools»(ref-278083-S19118114702008012100000) . Drive the camshaft outer bearing #1 from the camshaft outer bearing bore #1. Loosen the J 33049 expander assembly nut. See «Special Tools»(ref-278083-S19118114702008012100000) . Remove the camshaft outer bearing #1 from the J 33049 expander assembly. See «Special Tools»(ref-278083-S19118114702008012100000) . Remove the J 33049 from the engine block. See «Special Tools»(ref-278083-S19118114702008012100000) . Insert the J 33049 into the camshaft outer bearing #4. See «Special Tools»(ref-278083-S19118114702008012100000) . Tighten the J 33049 expander assembly nut until snug. See «Special Tools»(ref-278083-S19118114702008012100000) . Drive the camshaft outer bearing #4 from the camshaft outer bearing bore #4. Loosen the J 33049 expander assembly nut. See «Special Tools»(ref-278083-S19118114702008012100000) . Remove the camshaft outer bearing #4 from the J 33049 expander assembly. See «Special Tools»(ref-278083-S19118114702008012100000) .
6. Remove the J 33049 from the engine block. See «Special Tools»(ref-278083-S19118114702008012100000) .
7. Discard the camshaft bearings.

J 33049 Camshaft Bearing Service Kit. See Special Tools .

Scheme 40

1. Assemble the J 33049 handle (10), the expanding driver (4-8), the washer (2 or 3), and the expander assembly (15). See «Special Tools»(ref-278083-S19118114702008012100000) .
2. Install the NEW camshaft outer bearings #4 and #1. Install the NEW camshaft outer bearing #4 onto the J 33049 expander assembly. See «Special Tools»(ref-278083-S19118114702008012100000) . Tighten the J 33049 expander assembly nut until snug. See «Special Tools»(ref-278083-S19118114702008012100000) . Align the lubrication hole of the camshaft outer bearing #4 above the 3 o'clock position or the 9 o'clock position of the camshaft outer bearing bore #4 at the rear of the engine block. Drive the camshaft outer bearing #4 into the camshaft outer bearing bore #4 at the rear of the engine block. Loosen the J 33049 expander assembly nut. See «Special Tools»(ref-278083-S19118114702008012100000) . Remove the camshaft outer bearing #4 from the J 33049 expander assembly. See «Special Tools»(ref-278083-S19118114702008012100000) . Install the NEW camshaft outer bearing #1 onto the J 33049 expander assembly. See «Special Tools»(ref-278083-S19118114702008012100000) . Tighten the J 33049 expander assembly nut until snug. See «Special Tools»(ref-278083-S19118114702008012100000) . Align the lubrication hole of the camshaft outer bearing #1 above the 3 o'clock position or the 9 o'clock position of the camshaft outer bearing bore #1 at the front of the engine block. Drive the camshaft outer bearing #1 into the camshaft outer bearing bore #1 at the front of the engine block. Loosen the J 33049 expander assembly nut. See «Special Tools»(ref-278083-S19118114702008012100000) . Carefully slide the J 33049 into the engine block until the J 33049 expander assembly is positioned between the camshaft inner bearing bores. See «Special Tools»(ref-278083-S19118114702008012100000) .
3. Install the NEW camshaft inner bearings #3 and #2. Install the NEW camshaft inner bearing #3 onto the J 33049 expander assembly. See «Special Tools»(ref-278083-S19118114702008012100000) . Tighten the J 33049 expander assembly nut until snug. See «Special Tools»(ref-278083-S19118114702008012100000) . Align the lubrication hole of the camshaft inner bearing #3 above the 3 o'clock position or the 9 o'clock position of the camshaft inner bearing bore #3 of the engine block. Push the J 33049 guide cone into the camshaft front bearing bore #1 in order to align the J 33049 . See «Special Tools»(ref-278083-S19118114702008012100000) . Drive the camshaft inner bearing #3 into the camshaft inner bearing bore #3. Loosen the J 33049 expander assembly nut. See «Special Tools»(ref-278083-S19118114702008012100000) . Carefully slide the J 33049 until the J 33049 expander assembly is positioned between the camshaft inner bearing bore #2 and the camshaft outer bearing bore #1. See «Special Tools»(ref-278083-S19118114702008012100000) . Install the NEW camshaft inner bearing #2 onto the J 33049 expander assembly. See «Special Tools»(ref-278083-S19118114702008012100000) . Tighten the J 33049 expander assembly nut until snug. See «Special Tools»(ref-278083-S19118114702008012100000) . Align the lubrication hole of the camshaft inner bearing #2 above the 3 o'clock position or the 9 o'clock position of the camshaft inner bearing bore #2 of the engine block. Push the J 33049 guide cone into the camshaft front bearing bore #1 in order to align the J 33049 . See «Special Tools»(ref-278083-S19118114702008012100000) . Drive the camshaft inner bearing #2 into the camshaft inner bearing bore #2. Loosen the J 33049 expander assembly nut. See «Special Tools»(ref-278083-S19118114702008012100000) .
4. Carefully remove the J 33049 from the engine block. See «Special Tools»(ref-278083-S19118114702008012100000) .

J 38834 Balance Shaft Service Kit. See Special Tools .

1. Use the J 38834 in order to install the balance shaft rear bearing. See «Special Tools»(ref-278083-S19118114702008012100000) . Install the J 38834-3 onto the short threaded end of the J 38834-1. Install the J 38834 nut, the washer, and the bearing on the long threaded end of the J 38834-1. See «Special Tools»(ref-278083-S19118114702008012100000) . Install the J 38834-2 onto the J 38834-1 so that the smaller diameter of the J 38834-2 will be facing the front of the engine block. Install the J 38834-2 on the inside of the balance shaft front bearing bore. Lubricate the NEW balance shaft rear bearing with clean engine oil. Install the balance shaft rear bearing onto the J 38834-2. Align the balance shaft rear bearing for installation. Using a wrench secure the J 38834-1 into place. Rotate the J 38834 nut until the balance shaft rear bearing is properly and completely pushed into the balance shaft rear bearing bore. See «Special Tools»(ref-278083-S19118114702008012100000) .
2. Remove the J 38834 . See «Special Tools»(ref-278083-S19118114702008012100000) .

J 8062 Valve Spring Compressor. See Special Tools .

1. Use the J 8062 in order to compress the valve springs. See «Special Tools»(ref-278083-S19118114702008012100000) .
2. Remove the valve stem keys (1).
3. Remove the J 8062 from the cylinder head. See «Special Tools»(ref-278083-S19118114702008012100000) .
4. Remove the valve spring cap (2).
5. Remove the valve spring (3).
6. Remove the valve stem oil seal (4).
7. Discard the valve stem oil seal.
8. Remove the valve.

J 5830-02 Valve Guide Reamer Set. See Special Tools .

1. Measure the valve stem-to-guide clearance. Refer to «Cylinder Head Cleaning and Inspection»(ref-278083-S12123661622008012100000) .
2. Improper valve stem (1) to valve guide (2) clearance may cause excessive oil consumption.
3. Use the J 5830-3 in order to ream the exhaust valve guide in order to achieve the correct valve stem-to-guide clearance.
4. Always recondition the exhaust valve seat after reaming the exhaust valve guide bores and installing new exhaust valves.
5. Inspect the valves for the following: Burnt or damaged areas (1) Undersized margin (2) Bent stem (3) Scoring or other damage to the stem (4) Worn key groove (5) Worn stem tip (6)
6. Inspect the valve contact surface for the following: Undersized margin (1) Pitted surface (2) Burnt or eroded areas (3) Acceptable edge margin (4) Valves with excessive damage must be replaced. Minor imperfections of the valve or valve seat may be repaired.
7. Reconditioning of the valves and valve seats: The valves must seat perfectly for the engine to deliver optimum power and performance. Cooling the valve heads is another important factor. Good contact between each valve and valve seat in the cylinder head is necessary to insure that the heat in the valve head is properly carried away. Regardless of what type of equipment is used, it is essential that the valve guide bores are free from carbon or dirt in order to ensure the proper centering of the pilot in the valve guide. The valve seats should be concentric to within 0.05 mm (0.002 in) total indicator reading. Reface pitted valves on a valve refacing machine in order to ensure the correct relationship between the valve head and the valve stem. Replace the valve if the valve stem is excessively worn or warped. Replace the valve if the edge margin (4) of the valve head is less than 0.79 mm (0.031 in) thick after grinding. Several different types of equipment are available for reconditioning valves and valve seats. Follow the equipment manufacturer's recommendations for equipment use to attain the proper results.

J 21882 Oil Suction Pipe Installer. See Special Tools .

1. Apply clean engine oil GM P/N 12345610 (Canadian P/N 9931930) or equivalent, to the oil pump pressure relief valve, oil pump pressure relief valve spring, and oil pump body.
2. Install the following items: The oil pump pressure relief valve The oil pump pressure relief valve spring The oil pump pressure relief valve spring straight pin
3. Apply clean engine oil GM P/N 12345610 (Canadian P/N 993193) or equivalent, to the oil pump drive gear, the oil pump driven gear, and the oil pump body internal surfaces.
4. Install the oil pump drive gear and the oil pump driven gear into the oil pump body. Align the matchmarks on the oil pump drive and driven gears. Install the smooth side of the oil pump drive and driven gears toward the oil pump cover.
5. Install the oil pump cover.
6. Install the oil pump cover bolts. Tighten: Tighten the bolts to 12 N.m (106 lb in).
7. Inspect the oil pump for smoothness of operation by turning the oil pump driveshaft by hand.
8. Install the oil pump screen. If removed, replace the oil pump screen. The oil pump screen must have a good press fit into the oil pump body. Mount the oil pump in a soft jawed vise. Apply sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent, to the end of the oil pump screen pipe. Use the J 21882 and a soft-faced hammer in order to tap the oil pump screen into the pump body. See «Special Tools»(ref-278083-S19118114702008012100000) . The oil pump screen must align parallel with the bottom of the oil pan when the oil pan is installed.
9. Install the oil pump driveshaft and the NEW oil pump driveshaft retainer.

Thread Repair

General purpose thread repair kits are available commercially.

1. Determine the size, the pitch, and the depth of the damaged thread.
2. Adjust the stop collars on the cutting tool as needed. Tap the stop collars to the required depth.
3. Drill out the damaged thread.
4. Remove the chips.
5. Apply clean engine oil to the top thread.
6. Use the tap in order to cut new thread.
7. Clean the thread.
8. Screw the thread insert onto the mandrel of the thread insert installer. Engage the tang of the thread insert onto the end of the mandrel.
9. Lubricate the thread insert with clean engine oil - except when installing in aluminum - and install the thread insert.
10. If the tang of the thread insert does not break off when backing out the thread insert installer, break off the tang using a drift punch.

J 41712 Oil Pressure Switch Socket. See Special Tools .

1. Install a NEW oil filter bypass valve. Install the oil filter bypass valve into the oil gallery bore until slightly below flush with the surface of the engine block. Using a pointed punch, stake the engine block area around the oil filter bypass valve. Stake in 3 locations 120 degrees apart.
2. Apply sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent, to the outside diameter of the NEW front engine oil gallery plugs.
3. Install the NEW front engine block oil gallery plugs. A properly installed front engine oil gallery plug must be installed slightly below flush with the front face of the engine block.
4. Apply threadlock GM P/N 12345382 (Canadian P/N 10953489) or equivalent, to the outside diameter of the NEW engine block core hole plugs.
5. Install the NEW engine block core hole plugs. A properly installed engine block core hole plug must be installed flush or below the bottom of the chamfer (1) of the engine block core hole.
6. Install the crankshaft rear oil seal housing locator spring type S pin, if required.
7. Apply sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent, to the outside diameter of the NEW expansion cup plug.
8. Install the NEW expansion cup plug into the balance shaft rear bearing hole.
9. Apply sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent, to the outside diameter of the NEW expansion cup plug.
10. Install the NEW expansion cup plug into the camshaft rear bearing hole.
11. Apply sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent, to the threads of the engine block right rear oil gallery plug, the engine block left rear oil gallery plug, and the engine block left side oil gallery plug.
12. Install the engine block right rear oil gallery plug, the engine block left rear oil gallery plug, and the engine block left side oil gallery plug. Tighten: Tighten the engine block left side oil gallery plug and the engine block right rear oil gallery plug to 20 N.m (15 lb ft). Tighten the engine block left rear oil gallery plug to 30 N.m (22 lb ft).
13. Install the transmission locator dowel straight pins, if required.
14. Install the left side cylinder head locator dowel pins, if required. The installation height should be 6.3-6.5 mm (0.248-0.256 in) (a).
15. Install the right side cylinder head locator dowel pins, if required. The installation height should be 6.3-6.5 mm (0.248-0.256 in) (a).
16. Apply sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent, to the threads of the engine block coolant drain hole plugs.
17. Install the engine block coolant drain hole plugs. Tighten: Tighten the engine block coolant hole plugs to 20 N.m (15 lb ft).
18. If reusing the engine oil pressure sensor fitting, apply sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent, to the threads of the engine oil pressure sensor fitting.
19. Install the engine oil pressure sensor fitting. Tighten: Tighten the engine oil pressure sensor fitting to 15 N.m (11 lb ft).
20. Rotate the engine oil pressure sensor fitting clockwise to the proper position (1), 50 degrees from the centerline (2).
21. If reusing the engine oil pressure gage sensor, apply sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent, to the threads of the engine oil pressure gage sensor.
22. Install the engine oil pressure gage sensor using the J 41712 . See «Special Tools»(ref-278083-S19118114702008012100000) . Tighten: Tighten the engine oil pressure gage sensor to 30 N.m (22 lb ft).
23. Install the knock sensor (2).
24. Install the knock sensor retaining bolt (1). Tighten: Tighten the knock sensor to 25 N.m (18 lb ft).

J 45059 Angle Meter. See Special Tools .

1. Install the crankshaft bearings into the engine block.
2. Apply clean engine oil to the crankshaft bearings.
3. Apply clean engine oil to the crankshaft bearing journals.
4. Install the crankshaft.
5. Install the crankshaft bearings into the crankshaft bearing caps.
6. Apply clean engine oil to the crankshaft bearings.
7. Install the crankshaft bearing caps in the original position and with the arrow on the crankshaft bearing caps in the direction of the front of the engine block.
8. Install the NEW crankshaft bearing cap bolts until snug.
9. Thrust the crankshaft rearward in order to set and align the crankshaft thrust bearings and the crankshaft bearing caps.
10. Thrust the crankshaft forward in order to align the rear faces of the crankshaft thrust bearings.
11. Tighten the crankshaft bearing cap bolts. Tighten: Tighten the crankshaft bearing cap bolts on the first pass to 20 N.m (15 lb ft). Tighten the crankshaft bearing cap bolts on the final pass an additional 73 degrees using the J 45059 . See «Special Tools»(ref-278083-S19118114702008012100000) .
12. Measure the crankshaft end play. Firmly thrust the crankshaft rearward, and then forward. This will align the crankshaft rear bearing thrust surfaces. With the crankshaft pushed forward, insert a feeler gage between the crankshaft and the crankshaft rear bearing thrust surface to measure the clearance. Specification: Crankshaft end play 0.05-0.20 mm (0.002-0.008 in)
13. Rotate the crankshaft in order to check for binding. A bent crankshaft or lack of proper crankshaft bearing clearance may cause binding.
14. If the crankshaft does not turn freely, loosen the crankshaft bearing cap bolts on 1 crankshaft bearing cap at a time in order to determine the location of the binding. A lack of proper crankshaft bearing clearance may be caused by the following: Burrs on the crankshaft bearing cap Foreign material between the crankshaft bearing and the engine block Foreign material between the crankshaft bearing and the crankshaft bearing cap Damaged crankshaft bearing Improper size crankshaft bearing

J 35621-B Rear Main Seal Installer. See Special Tools .

1. Install the crankshaft rear oil seal housing retainer stud. Tighten: Tighten the crankshaft rear oil seal housing retainer stud to 6 N.m (53 lb in).
2. Install the NEW crankshaft rear oil seal housing gasket.
3. Install the crankshaft rear oil housing onto the crankshaft rear oil seal housing retainer stud.
4. Install the crankshaft rear oil seal housing nut and bolts. Tighten: Tighten the crankshaft rear oil seal housing nut and bolts to 12 N.m (106 lb in).
5. Inspect the J 35621-B flange for imperfections that may damage the crankshaft rear oil seal. See «Special Tools»(ref-278083-S19118114702008012100000) . Minor imperfections may be removed with a fine grade emery cloth.
6. Clean the crankshaft sealing surface with a clean, lint free towel. Inspect the lead-in edge of the crankshaft for burrs or sharp edges that could damage the rear main oil seal. Remove the burrs or sharp edges with a fine grade emery cloth before proceeding.
7. Carefully remove the protection sleeve from the NEW crankshaft rear oil seal.
8. Install the crankshaft rear oil seal onto the J 35621-B . See «Special Tools»(ref-278083-S19118114702008012100000) .
9. Install the J 35621-B onto the rear of the crankshaft and hand tighten the tool bolts until snug. See «Special Tools»(ref-278083-S19118114702008012100000) .
10. Install the crankshaft rear oil seal onto the crankshaft and into the crankshaft rear oil seal housing. Turn the J 35621-B wing nut clockwise until the crankshaft rear oil seal is installed near to flush and square to the crankshaft rear oil seal housing. See «Special Tools»(ref-278083-S19118114702008012100000) . Increased resistance will be felt when the crankshaft rear oil seal has reached the bottom of the crankshaft rear oil seal housing bore. Turn the J 35621-B wing nut counterclockwise to release the J 35621-B from the crankshaft rear oil seal. See «Special Tools»(ref-278083-S19118114702008012100000) .
11. Remove the J 35621-B from the crankshaft. See «Special Tools»(ref-278083-S19118114702008012100000) .
12. Wipe off any excess engine oil with a clean rag.

Piston Selection

1. Use the J 8087 in order to measure the cylinder bore diameter. Measure at a point 64 mm (2.5 in) from the top of the cylinder bore and 90 degrees to the crankshaft centerline.
2. Measure the J 8087 with a micrometer and record the reading.
3. With a micrometer or caliper at a right angle to the piston pin bore, measure the piston 11 mm (0.433 in) from the bottom of the skirt.
4. Subtract the piston diameter from the cylinder bore diameter in order to determine piston-to-bore clearance. Refer to «Engine Mechanical Specifications»(ref-278083-S33878724872008012100000) .
5. If the proper clearance cannot be obtained, then select another piston and measure the clearances. If the proper fit cannot be obtained, the cylinder bore may require honing or boring.
6. When the piston-to-cylinder bore clearance is within specifications, permanently mark the top of the piston for installation into the proper cylinder.

J 5590 Pinion Bearing Race Installer - Rear. See Special Tools .

1. Install the crankshaft balancer key into the crankshaft keyway. The crankshaft balancer key should be parallel to the crankshaft or with a slight incline.
2. Align the keyway of the crankshaft sprocket with the crankshaft balancer key.
3. Use the J 5590 in order to install the crankshaft sprocket. See «Special Tools»(ref-278083-S19118114702008012100000) .
4. Rotate the crankshaft until the crankshaft sprocket alignment mark is at the 12 o'clock position.
5. Install the camshaft sprocket and the camshaft timing chain.
6. Look to ensure that the crankshaft sprocket is aligned at the 12 o'clock position and camshaft sprocket is aligned at the 6 o'clock position.
7. Install camshaft sprocket bolts. Tighten: Tighten the camshaft sprocket bolts to 25 N.m (18 lb ft).
8. Install the timing chain tensioner bracket and bolt (227 and 228). Tighten: Tighten the timing chain tensioner bracket bolt to 12 N.m (106 lb in).
9. Install the timing chain tensioner shoe (229) using an upwards motion.
10. Install the crankshaft position sensor reluctor ring. Align the keyway on the crankshaft position sensor reluctor ring with the crankshaft balancer key in the crankshaft. Use the J 5590 in order to push the crankshaft position sensor reluctor ring onto the crankshaft until completely seated against the crankshaft sprocket. See «Special Tools»(ref-278083-S19118114702008012100000) .

J 23523-F Balancer Remover and Installer

1. Look to ensure that the crankshaft balancer front groove pin is installed in the proper location, if applicable. The length and location of the pins must be the same as the original length and location.
2. Apply a small amount of adhesive GM P/N 12346141 (Canadian P/N 10953433) or equivalent, onto the crankshaft balancer keyway in order to seal the crankshaft balancer keyway and crankshaft joint.
3. Align the keyway of the crankshaft balancer with the crankshaft balancer key.
4. Install the crankshaft balancer onto the end of the crankshaft.
5. Use the J 23523-F in order to press the crankshaft balancer onto the crankshaft. Install the J 23523-F plate and bolts onto the front of the crankshaft balancer. Tighten: Tighten the J 23523-F plate bolts to 25 N.m (18 lb ft). Install the J 23523-F screw into the end for the crankshaft. Install the J 23523-F bearing, the washer, and the nut onto the J 23523-F screw. Rotate the J 23523-F nut clockwise until the crankshaft balancer hub is completely seated against the crankshaft position sensor reluctor ring.
6. Remove the J 23523-F .
7. Install the crankshaft pulley and bolts. Finger tighten all bolts until snug. Tighten: Tighten the crankshaft pulley bolts to 58 N.m (43 lb ft).
8. Ensure that the crown of the crankshaft balancer washer (2) is faced away from the engine.
9. Install the crankshaft balancer washer and the bolt. Tighten: Tighten the crankshaft balancer bolt to 95 N.m (70 lb ft).

J 45059 Angle Meter. See Special Tools .

1. Clean the cylinder head gasket surfaces on the engine block.
2. Inspect the cylinder head locator dowel pins for proper installation. The installation height should be 6.3-6.5 mm (0.248-0.256 in) (a).
3. Clean the cylinder head gasket surfaces on the cylinder head.
4. Install the NEW cylinder head gasket in position over the cylinder head locator dowel pins.
5. Install the cylinder head onto the engine block. Guide the cylinder head carefully into place over the dowel pins and the cylinder head gasket.
6. Apply sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent, to the threads of the NEW cylinder head bolts.
7. Install the NEW cylinder head bolts finger tight.
8. Tighten the cylinder head bolts in sequence on the first pass. Tighten: Tighten the bolts in sequence on the first pass to 30 N.m (22 lb ft).
9. Use the J 45059 in order to tighten the cylinder head bolts in sequence on the final pass. See «Special Tools»(ref-278083-S19118114702008012100000) . Tighten: Tighten the long bolts (1, 4, 5, 8, and 9) on the final pass in sequence to 75 degrees. Tighten the medium bolts (12 and 13) on the final pass in sequence to 65 degrees. Tighten the short bolts (2, 3, 6, 7, 10, and 11) on the final pass in sequence to 55 degrees.
10. Install the spark plug wire support and bolts. Tighten: Tighten the spark plug wire support bolts to 12 N.m (106 lb in).
11. Measure the spark plugs for the proper gap. Adjust the spark plug gap if necessary. Specification: Spark plug gap to 1.52 mm (0.060 in).
12. Install the spark plugs. Tighten: Tighten the spark plugs to 15 N.m (11 lb ft).
13. If reusing the engine coolant temperature gage sensor, if applicable, apply sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent, to the threads of the engine coolant temperature gage sensor.
14. Install the engine coolant temperature gage sensor, if applicable. Tighten: Tighten the engine coolant temperature gage sensor to 20 N.m (15 lb ft).
15. If reusing the engine coolant temperature sensor, if applicable, apply sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent, to the threads of the engine coolant temperature gage sensor.
16. Install the engine coolant temperature sensor, if applicable. Tighten: Tighten the engine coolant temperature sensor to 20 N.m (15 lb ft).

J 45059 Angle Meter. See Special Tools .

1. Clean the cylinder head gasket surfaces on the engine block.
2. Inspect the cylinder head locator dowel pins for proper installation. The installation height should be 6.3-6.5 mm (0.248-0.256 in) (a).
3. Clean the cylinder head gasket surfaces on the cylinder head.
4. Install the NEW cylinder head gasket in position over the cylinder head locator dowel pins.
5. Install the cylinder head onto the engine block. Guide the cylinder head carefully into place over the dowel pins and the cylinder head gasket.
6. Apply sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent, to the threads of the NEW cylinder head bolts.
7. Install the NEW cylinder head bolts finger tight.
8. Tighten the cylinder head bolts in sequence on the first pass. Tighten: Tighten the bolts in sequence on the first pass to 30 N.m (22 lb ft).
9. Use the J 45059 in order to tighten the cylinder head bolts in sequence on the final pass. See «Special Tools»(ref-278083-S19118114702008012100000) . Tighten: Tighten the long bolts (1, 4, 5, 8, and 9) on the final pass in sequence to 75 degrees. Tighten the medium bolts (12 and 13) on the final pass in sequence to 65 degrees. Tighten the short bolts (2, 3, 6, 7, 10, and 11) on the final pass in sequence to 55 degrees.
10. Install the spark plug wire support and bolts. Tighten: Tighten only the rear spark plug wire support bolt to 12 N.m (106 lb in).
11. Remove the front spark plug wire support bolt. The front spark plug wire support bolt is used to fasten the oil level indicator tube, and will be installed within the oil level indicator tube installation procedure.
12. Measure the spark plugs for the proper gap. Adjust the spark plug gap if necessary. Specification: Spark plug gap to 1.52 mm (0.060 in).
13. Install the spark plugs. Tighten: Tighten the spark plugs to 15 N.m (11 lb ft).

J 41240 Fan Clutch Remover and Installer. See Special Tools .

1. If reusing the fasteners, apply sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent, to the threads of the water pump bolts.
2. Install the water pump and the NEW water pump gaskets.
3. Install the water pump bolts. Tighten: Tighten the water pump bolts to 45 N.m (33 lb ft).
4. Install the water pump inlet hose and the water pump inlet hose clamps.
5. Install the fan and water pump pulley and bolts using the J 41240 . See «Special Tools»(ref-278083-S19118114702008012100000) . Tighten: Tighten the fan and water pump pulley bolts to 25 N.m (18 lb ft).

J 45299 Engine Preluber. See Special Tools .

1. Remove the engine oil filter and fill with clean engine oil.
2. Install the oil filter. Tighten: Tighten the oil filter to 30 N.m (22 lb ft).
3. Locate the engine block left oil gallery plug and remove.
4. Install the M16 x 1.5 adapter P/N 509375.
5. Install the flexible hose to the adapter and open the valve.
6. Pump the handle on the J 45299 in order to flow a minimum of 1-1. See «Special Tools»(ref-278083-S19118114702008012100000) .9 liters (1-2 quarts) engine oil. Observe the flow of engine oil through the flexible hose and into the engine assembly.
7. Close the valve and remove the flexible hose and adapter from the engine.
8. Install the gallery plug to the engine. Tighten: Tighten the oil gallery plug to 60 N.m (44 lb ft).
9. Top-off the engine oil to the proper level.

Balance Shaft

The cast iron balance shaft is mounted in the crankcase above and in-line with the camshaft. A camshaft gear drives the gear attached to the balance shaft. The front end of the balance shaft is supported by a ball-type bearing. The rear end of the balance shaft uses a sleeve-type bearing.

Camshaft

The steel camshaft is supported by four bearings pressed into the engine block. The camshaft timing chain sprocket mounted to the front of the camshaft is driven by the crankshaft sprocket through a camshaft timing chain.

Crankshaft

The cast nodular iron crankshaft is supported by four crankshaft bearings. The number four crankshaft bearing at the rear of the engine is the end thrust bearing. The crankshaft bearings are retained by bearing caps that are machined with the engine block for proper alignment and clearances. The crankshaft position sensor reluctor ring has three lugs used for crankshaft timing and is constructed of powdered metal. The crankshaft position sensor reluctor ring has a slight interference fit onto the crankshaft and an internal keyway for correct positioning.

Cylinder Heads

The cast iron cylinder heads have one intake and one exhaust valve for each cylinder. A spark plug is located between the valves in the side of the cylinder head. The valve guides and seats are integral to the cylinder head. The 4.3L heavy duty applications have pressed in exhaust valve seats. The valve rocker arms are positioned on the valve rocker arm supports and retained by a bolt.

Engine Block

The cast iron engine block has six cylinders arranged in a V shape with three cylinders in each bank. Starting at the front side of the engine block, the cylinders in the left bank are numbered 1-3-5 and cylinders in the right bank are numbered 2-4-6, when viewed from the rear. The firing order of the cylinders is 1-6-5-4-3-2. The cylinders are encircled by coolant jackets.

Exhaust Manifolds

The cast iron exhaust manifolds direct exhaust gases from the combustion chambers to the exhaust system.

Intake Manifold

The intake manifold is a two-piece design. The upper portion is made from a composite material and the lower portion is cast aluminum. The throttle body attaches to the upper manifold. The Central Multipoint Flexible Injection system uses multiple fuel injectors to meter and distribute fuel to each engine cylinder. The Central (MFI) is retained by a bracket bolted to the lower intake manifold. The fuel meter body also houses the pressure regulator. Metal inlet and outlet fuel lines and nylon delivery tubes connect to the Central (MFI) unit. The delivery tubes independently distribute fuel to each cylinder through injectors located at the port entrance of each manifold runner where the fuel is atomized.

Valve Train

Motion is transmitted from the camshaft through the hydraulic roller valve lifters and the tubular valve pushrods to the roller type valve rocker arms. The roller type valve rocker arm pivots on a needle type bearing in order to open the valve. The valve rocker arms for each bank of cylinders are mounted to a one piece valve rocker arm support. Each valve rocker arm is retained on the valve rocker arm support and the cylinder head by a bolt. The hydraulic valve lifters keep all the parts of the valve train in constant contact. Each hydraulic valve lifter acts as an automatic adjuster and maintains zero lash in the valve train. This eliminates the need for periodic valve adjustment.

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

1. A component comparison from the previous year
2. Fastener changes
3. Torque values and/or fastener tightening strategies
4. Changed engine specifications
5. New sealants and/or adhesives
6. Disassembly and assembly procedure revisions
7. Engine mechanical diagnostic procedure revisions
8. New special tools required

Component Comparison

Powdered metal connecting rods have replaced forged connecting rods.

New Sealants and/or Adhesives

No new sealants or adhesives for 2007.

Cleanliness and Care

1. Throughout this section, it should be understood that proper cleaning and protection of machined surfaces and friction areas is part of the repair procedure. This is considered standard shop practice even if not specifically stated.
2. When any internal engine parts are serviced, care and cleanliness is important.
3. When components are removed for service, the components should be marked, organized or retained in a specific order for re-assembly.
4. At the time of installation, the components should be installed in the same location and with the same mating surface as when removed.
5. An automobile engine is a combination of many machined, honed, polished and lapped surfaces with tolerances that are measured in millimeters or thousandths of an inch. The surfaces should be protected to avoid component damage.
6. Apply a liberal amount of clean engine oil to friction areas during assembly.
7. Proper lubrication will protect and lubricate friction areas during initial operation.

Separating Parts

Mark or identify the following components

1. Piston and the piston pin
2. Piston to the specific cylinder bore
3. Piston rings to the specific cylinder bore
4. Connecting rod to the crankshaft journal
5. Connecting rod to connecting rod cap
6. Crankshaft bearings and connecting rod bearings
7. Engine camshaft and valve lifters
8. Valve lifters, valve rocker arms, and valve rocker arm supports
9. Valve to the valve guide
10. Valve spring to cylinder head location
11. Engine block bearing cap location and direction
12. Oil pump drive and driven gears

Gasket Reuse and Applying Sealant

1. Do not reuse any gasket unless specified.
2. Gaskets that can be reused will be identified in the service procedure.
3. Do not apply sealant to any gasket or sealing surface unless specified in the service procedure.

Separating Components

1. Use a rubber mallet in order to separate the components.
2. Bump the part sideways in order to loosen the components.
3. Bumping of the component should be done at bends or reinforced areas of the component to prevent distortion of the components.

Cleaning Gasket Surfaces

1. Use care to avoid gouging or scraping the sealing surfaces.
2. Use a plastic or wood scraper in order to remove all the sealant from the components. Do not use any other method or technique to remove the sealant or the gasket material from a part.
3. Do not use abrasive pads, sand paper, or power tools to clean the gasket surfaces. These methods of cleaning can cause damage to the component sealing surfaces. Abrasive pads also produce a fine grit that the oil filter cannot remove from the engine oil. This fine grit is an abrasive and can cause internal engine damage.

Sealant Types

The following 2 major types of sealant are commonly used in engines

1. Anaerobic sealant room temperature vulcanizing (RTV)
2. Anaerobic sealant, which include the following: Gasket eliminator Pipe Threadlock

Anaerobic Type Room Temperature Vulcanizing (RTV) Sealant

Anaerobic type room temperature vulcanizing (RTV) sealant cures in the absence of air. This type of sealant is used where 2 components, such as the intake manifold and the engine block, are assembled together.

Use the following information when using RTV sealant

1. Do not use RTV sealant in areas where extreme temperatures are expected. These areas include: The exhaust manifold The head gasket Any other surfaces where a different type of sealant is specified in the service procedure
2. Always follow all the safety recommendations and the directions that are on the RTV sealant container.
3. Use a plastic or wood scraper in order to remove all the RTV sealant from the components.
4. The surfaces to be sealed must be clean and dry.
5. Use a RTV sealant bead size as specified in the service procedure.
6. Apply the RTV sealant bead to the inside of any bolt holes areas.
7. Assemble the components while the RTV sealant is still wet to the touch, within 3 minutes.
8. Tighten the fasteners in sequence, if specified, and to the proper torque specifications.

Anaerobic Type Gasket Eliminator Sealant

Anaerobic type gasket eliminator sealant cures in the absence of air. This type of sealant is used where 2 rigid parts, such as castings, are assembled together. When 2 rigid parts are disassembled and no sealant or gasket is readily noticeable, then the 2 parts were probably assembled using an anaerobic type gasket eliminator sealant.

Use the following information when using gasket eliminator sealant

1. Always follow all the safety recommendations and directions that are on the gasket eliminator sealant container.
2. Apply a continuous bead of gasket eliminator sealant to one flange. The surfaces to be sealed must be clean and dry.

Note. Do not allow the sealant to enter a blind hole. The sealant may prevent the fastener from achieving proper clamp load, cause component damage when the fastener is tightened, or lead to component failure.

Anaerobic Type Threadlock Sealant

Anaerobic type threadlock sealant cures in the absence of air. This type of sealant is used for threadlocking and sealing of bolts, fittings, nuts, and studs. This type of sealant cures only when confined between 2 close fitting metal surfaces.

Use the following information when using threadlock sealant

1. Always follow all safety recommendations and directions that are on the threadlock sealant container.
2. The threaded surfaces to be sealed must be clean and dry.
3. Apply the threadlock sealant as specified on the threadlock sealant container.
4. Tighten the fasteners in sequence, if specified, and to the proper torque specifications.

Anaerobic Type Pipe Sealant

Anaerobic type pipe sealant cures in the absence of air and remains pliable when cured. This type of sealant is used where 2 parts are assembled together and require a leak proof joint.

Use the following information when using pipe sealant

1. Do not use pipe sealant in areas where extreme temperatures are expected. These areas include: The exhaust manifold The head gasket Surfaces where a different sealant is specified
2. Always follow all the safety recommendations and the directions that are on the pipe sealant container.
3. The surfaces to be sealed must be clean and dry.
4. Use a pipe sealant bead of the size or quantity as specified in the service procedure.
5. Apply the pipe sealant bead to the inside of any bolt hole areas.
6. Apply a continuous bead of pipe sealant to one sealing surface.
7. Tighten the fasteners in sequence, if specified, and to the proper torque specifications.

Tools and Equipment

Special tools are listed and illustrated throughout this section with a complete listing at the end of the section. The tools (or the equivalents) are specially designed to quickly and safely accomplish the operations for which the tools are intended. The use of special tools will also minimize possible damage to engine components. Some precision measuring tools are required for inspection of certain critical components. Torque wrenches and a torque angle meter are necessary for the proper tightening of various fasteners.

To properly service the engine assembly, the following items should be readily available

1. Approved eye protection and safety gloves
2. A clean, well-lit, work area
3. A suitable parts cleaning tank
4. A compressed air supply
5. Trays or storage containers to keep parts and fasteners organized
6. An adequate set of hand tools
7. Approved engine repair stand
8. An approved engine lifting device that will adequately support the weight of the components