Chevrolet Silverado / GMC Sierra. Service manual — part 9

Worn, damaged or improperly installed valve
rocker arm

Inspect the valve rocker arms.

Repair or replace damaged components
as required.

Worn or damaged valve rotator

Inspect the valve rotators.

Repair or replace damaged components
as required.

Broken valve spring

Inspect the valve springs.

Repair or replace damaged components
as required.

Worn, damaged or stuck valves, carbon on
the valve stem or valve seat

Inspect the valves.

Inspect the valve guides.

Repair or replace damaged components
as required.

Worn or damaged valve guide

Inspect the valve guides.

Inspect the valves.

Repair or replace damaged components
as required.

Worn, damaged or bent valve push rod

Inspect the valve rocker arms.

Inspect the valve push rods.

Inspect the valve lifters.

Repair or replace damaged components
as required.

Worn, damaged or dirty valve lifter

Inspect the valve lifters.

Repair or replace damaged components
as required.

Worn or damaged camshaft lobes

Inspect the engine camshaft lobes.

Repair or replace damaged components
as required.

Worn, damaged, improperly installed or
loose timing chain and sprockets

Inspect the timing chain and sprockets.

Repair or replace damaged components
as required.

Worn, damaged or improperly installed
timing chain tensioner, if equipped

Inspect the timing chain tensioner.

Repair or replace damaged components

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Mechanical - 4.3L - Sierra & Silverado

LOWER ENGINE NOISE, REGARDLESS OF ENGINE SPEED

as required.

Cause

Correction

Low oil pressure

1. Verify oil pressure. Refer to Oil

Pressure Diagnosis and Testing.

2. Repair or replace damaged components

as required.

Detonation or spark knock

1. Verify the operation of the ignition

controls system. Refer to Diagnostic
System Check - Vehicle .

2. Repair or replace damaged components

as required.

Worn, damaged, or improperly installed
accessory drive belt - severe cracking, bumps
or missing segments in the accessory drive
belt

1. Inspect the accessory drive system

components.

2. Repair or replace damaged components

as required.

Worn, damaged, or improperly installed
accessory drive system components

1. Inspect the accessory drive system

components.

2. Repair or replace damaged components

as required.

Worn, damaged, or improperly installed
crankshaft balancer

1. Inspect the crankshaft balancer.

2. Inspect the crankshaft.

3. Repair or replace damaged components

as required.

Worn, damaged, or improperly installed
engine flywheel

1. Inspect the engine flywheel.

2. Inspect the engine flywheel bolts.

3. Inspect the torque converter.

4. Inspect the torque converter bolts.

5. Inspect the crankshaft.

6. Repair or replace damaged components

as required.

Worn, damaged, or improperly installed
torque converter

1. Inspect the torque converter.

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Mechanical - 4.3L - Sierra & Silverado

2. Inspect the torque converter bolts.

3. Inspect the engine flywheel.

4. Repair or replace damaged components

as required.

Damaged oil pan, contacting the oil pump
screen-An oil pan that has been damaged may
loosen, improperly position, or restrict oil
flow at the oil pump screen, preventing
proper oil flow to the oil pump

1. Inspect the oil pan.

2. Inspect the oil pump screen.

3. Repair or replace damaged components

as required.

Worn, damaged, improperly installed or
restricted oil pump screen-An oil pan that has
been damaged may loosen, improperly
position, or restrict oil flow at the oil pump
screen, preventing proper oil flow to the oil
pump

1. Inspect the oil pan.

2. Inspect the oil pump screen.

3. Repair or replace damaged components

as required.

Worn, damaged, or improperly installed
piston-Pistons must be installed with the
mark, or dimple, on the top of the piston,
facing the front of the engine
Piston pins must be centered in the
connecting rod pin bore.

1. Inspect the spark plugs. Refer to Spark

Plug Inspection .

2. Verify engine compression. Refer to

Engine Compression Test.

3. Inspect the cylinder bores.

4. Inspect the pistons.

5. Inspect the piston pins.

6. Inspect the connecting rods.

7. Repair or replace damaged components

as required.

Worn, damaged, or improperly installed
connecting rod bearing

1. Inspect the connecting rods.

2. Inspect the connecting rod bearings.

3. Inspect the crankshaft connecting rod

journals.

4. Repair or replace damaged components

as required.

Worn, damaged, or improperly installed
crankshaft bearing

1. Inspect the crankshaft bearings.

2. Inspect the crankshaft journals.

3. Repair or replace damaged components

as required.

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Mechanical - 4.3L - Sierra & Silverado

ENGINE NOISE UNDER LOAD

Cause

Correction

Low oil pressure

1. Perform an oil pressure test. Refer to

Oil Pressure Diagnosis and Testing.

2. Repair or replace as required.

Detonation or spark knock

1. Verify the correct operation of the

ignition controls. Refer to Diagnostic
System Check - Vehicle .

2. Repair or replace damaged components

as required.

Worn, damaged, or improperly installed
engine flywheel

1. Inspect the engine flywheel.

2. Inspect the engine flywheel bolts.

3. Inspect the torque converter.

4. Inspect the torque converter bolts.

5. Inspect the crankshaft.

6. Repair or replace damaged components

as required.

Worn, damaged, or improperly installed
torque converter

1. Inspect the torque converter.

2. Inspect the torque converter bolts.

3. Inspect the engine flywheel.

4. Repair or replace damaged components

as required.

Worn, damaged, or improperly installed
pistons-Pistons must be installed with the
mark, or dimple, on the top of the piston,
facing the front of the engine
Piston pins must be centered in the
connecting rod pin bore.

1. Inspect the cylinder bores.

2. Inspect the pistons.

3. Inspect the piston pins.

4. Inspect the connecting rods.

5. Repair or replace damaged components

as required.

Worn, damaged, or improperly installed
connecting rod bearing

1. Inspect the connecting rods.

2. Inspect the connecting rod bearings.

3. Inspect the crankshaft connecting rod

journals.

4. Repair or replace damaged components

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Mechanical - 4.3L - Sierra & Silverado