GMC Powertrain 4.3 L User manual

Engine
Engine Model:
General Motors 4.3 L Powertrain
Generator Models:
30--45 kW
TP-6103 1/01
Service

CAUTION
Caution: In order to reduce the chance of personal injury and/or property damage, carefully observe the instructions
that follow.
The service manual of General Motors Powertrain is intended for use by professional, qualified technicians.
Attempting repairs or service without the appropriate training, tools, and equipment could cause injury to you or others,
damage the equipment, or cause the equipment to operate improperly.
Proper equipment and repair are important to the safety of the service technician and to the safe, reliable operation of
the equipment. If you need to replace a part, use the same part number or an equivalent part. Do not use a
replacement part of lesser quality.
The service procedures we recommend and describe in this service manual are effective methods of performing
service and repair. Some of the procedures require the use of tools that are designed for specific purposes.
Accordingly, any person who intends to use a replacement part, a service procedure, or a tool that is not recommended
by General Motors Powertrain must first establish that there is no jeopardy to personal safety or the safe operation of
the equipment.
This manual contains various Cautions and Notices that you must observe carefully to reduce the risk of personal
injury during service or repair. Improper service or repair may damage the equipment or render the equipment unsafe.
These Cautions and Notices are not exhaustive. General Motors Powertrain cannot possibly warn of all the potentially
hazardous consequences of failure to follow these instructions.

TP-6103 1/01 Table of Contents
Table of Contents
Caution Inside Front Cover.....................................................................
Introduction i..................................................................................
Cautions and Notices I.........................................................................
Fastener Tightening Specifications 6-1.........................................................
Engine Mechanical Specifications 6-4..........................................................
GM SPO Group Numbers 6-6...................................................................
Sealers, Adhesives, and Lubricants 6-9.........................................................
Diagnostic Information and Procedures 6-10....................................................
Base Engine Misfire Diagnostic 6-10......................................................
Engine Compression Test 6-11...........................................................
Engine Noise Diagnostic 6-12............................................................
Valve Train Diagnosis 6-13..............................................................
Excessive Oil Consumption 6-15.........................................................
Oil Pressure Diagnosis and Testing 6-15..................................................
Oil Leak Diagnosis 6-16.................................................................
Drive Belts 6-18........................................................................
Drive Belt Chirping 6-18.................................................................
Drive Belt Squeal 6-20..................................................................
Drive Belt Whine 6-21..................................................................
Drive Belt Rumbling 6-22................................................................
Drive Belt Vibration 6--23................................................................
Drive Belt Falls Off 6--24.................................................................
Drive Belt Excessive Wear 6--25..........................................................
Drive Belt Tensioner 6-26...............................................................
Component Locator 6-28......................................................................
Intake Manifold 6-28....................................................................
Cylinder Head and Exhaust Manifold 6-30.................................................
Cylinder Block and Components 6-31.....................................................
Lower Engine Block and Oil Pan 6-33.....................................................
Repair Instruction—Removal 6-34..............................................................
Draining Fluids and Oil Filter Removal 6-34................................................
Engine Flywheel Removal 6-35..........................................................
Clutch Pilot Bearing Removal 6-35.......................................................
Exhaust Manifold Removal 6-36..........................................................
Oil Level Indicator and Tube Removal 6-37................................................
Water Pump Removal 6-38..............................................................
Crankshaft Balancer Removal 6-39.......................................................
Valve Rocker Arm Cover Removal 6-40...................................................
Distributor Removal 6-42................................................................
Intake Manifold Removal 6-43...........................................................
Valve Rocker Arm and Push Rod Removal 6-44............................................
Cylinder Head Removal 6-45............................................................
Valve Lifter Removal 6-50...............................................................
Oil Pan Removal 6-51..................................................................
Oil Pump Removal 6-52.................................................................
Engine Front Cover Removal 6-53........................................................
Timing Chain and Sprockets Removal 6-54................................................
Balance Shaft Removal 6-56............................................................
Camshaft Removal 6-57................................................................
Piston, Connecting Rod, and Bearing Removal 6-58........................................

TP-6103 1/01Table of Contents, continued
Table of Contents, continued
Crankshaft Rear Oil Seal Removal 6-59...................................................
Crankshaft and Bearings Removal 6-61...................................................
Engine Block Plug Removal 6-62.........................................................
Inspection 6-66...............................................................................
Engine Block Clean and Inspect 6-66.....................................................
Cylinder Boring and Honing 6-67.........................................................
Boring Procedure 6-68..................................................................
Piston and Connecting Rod Disassemble 6-69.............................................
Piston, Connecting Rod, and Bearings Clean/Inspect 6-70...................................
Piston Selection 6-73...................................................................
Piston and Connecting Rod Assemble 6-74................................................
Crankshaft and Bearings Clean and Inspect 6-76...........................................
Bearing Clearance Measuring Procedure 6-80.............................................
Crankshaft Balancer Clean and Inspect 6-86...............................................
Engine Flywheel Clean and Inspect 6-86..................................................
Camshaft and Bearings Clean and Inspect 6-88............................................
Camshaft Bearing Removal 6-89.........................................................
Camshaft Bearing Installation 6-91.......................................................
Balance Shaft Bearing and/or Bushing Removal 6-93.......................................
Balance Shaft Clean and Inspect 6-94....................................................
Balance Shaft Bearing and/or Bushing Installation 6-95.....................................
Timing Chain and Sprockets Clean and Inspect 6-96........................................
Valve Rocker Arm and Push Rods Clean and Inspect 6-96...................................
Valve Lifters and Guides Clean and Inspect 6-98...........................................
Cylinder Head Disassemble 6-99.........................................................
Cylinder Head Clean and Inspect 6-99....................................................
Valve Guide Reaming/Valve and Seat Grinding 6-102.......................................
Cylinder Head Assemble 6-104..........................................................
Oil Pump Disassemble 6-106............................................................
OIl Pump Clean and Inspect 6-108.......................................................
Oil Pump Assemble 6-109...............................................................
Valve Rocker Arm Cover Clean and Inspect 6-111..........................................
Oil Pan Clean and Inspect 6-112.........................................................
Intake Manifold Disassemble 6-113.......................................................
Intake Manifold Clean and inspect 6-117..................................................
Intake Manifold Assemble 6-118.........................................................
Exhaust Manifold Clean and inspect 6-123.................................................
Water Pump Clean and inspect 6-124.....................................................
Thread Repair 6-125....................................................................
Service Prior to Assembly 6-126.........................................................
Installation 6-128..............................................................................
Engine Block Plug Installation 6--128......................................................
Crankshaft and Bearings Installation 6-132................................................
Crankshaft Rear Oil Seal and Housing Installation 6-134....................................
Piston, Connecting Rod, and Bearing Installation 6-136.....................................
Balance Shaft Installation 6-139..........................................................
Timing Chain and Sprockets Installation 6-142.............................................
Engine Front Cover Installation 6-144.....................................................
Oil Pump Installation 6-145..............................................................
Oil Pan Installation 6-146................................................................
Crankshaft Balancer Installation 6-149....................................................
Valve Lifter Installation 6-151............................................................
Cylinder Head Installation 6-152..........................................................

TP-6103 1/01 Table of Contents, continued
Table of Contents, continued
Valve Rocker Arm and Push Rod Installation 6-157.........................................
Intake Manifold Installation 6-159.........................................................
Distributor Installation 6-161.............................................................
Valve Rocker Arm Cover Installation 6-164................................................
Oil Level Indicator and Tube Installation 6-166.............................................
Water Pump Installation 6-167...........................................................
Exhaust Manifold Installation 6-168.......................................................
Clutch Pilot Bearing Installation 6-169.....................................................
Engine Flywheel Installation 6-169........................................................
Engine Setup and Testing 6-171................................................................
Description and Operation 6-172...............................................................
Engine Component Description 6-172.....................................................
Drive Belt System Description 6-172......................................................
New Product Information 6-173..........................................................
Lubrication 6-175......................................................................
Cleanliness and Care 6-175.............................................................
Replacing Engine Gaskets 6-176.........................................................
Use of RTV and Anaerobic Sealer 6-176..................................................
Separating Parts 6-177.................................................................
Tools and Equipment 6-178..............................................................
Special Tools and Equipment 6-179.............................................................

TP-6103 1/01Table of Contents, continued

TP-6103 1/01 iIntroduction
Introduction
This service manual provides the service technician
with information to service the General Motors
Powertrain engines.
In general, this manual covers the service of the engine
and associated standard equipment. In some cases the
engine is supplied with accessories and equipment that
are unique to the application. If service information is
required on such unique accessories or equipment,
contact the generator set manufacturer who will forward
the proper information or advise the service technician
where it can be obtained.
The information in this manual is grouped in sections
according to the type of work being performed. The
various sections are indicated in the Table of Contents of
the manual.
This manual has been reprinted by the generator set
manufacturer with the permission of General Motors
Powertrain.
This manual is a reproduction of a General Motors
Powertrain publication and contains information
pertaining to industrial generator set engines. Some
information pertains to other applications of the engine.
The accuracy and completeness of information is the
sole responsibility of General Motors Powertrain.
The descriptions and specifications contained in this
manual were in effect at the time the book was released
by General Motors Powertrain. The generator set
manufacturer and General Motors Powertrain reserve
the right to discontinue models or change specs or
design at any time without notice and without incurring
obligation.

TP-6103 1/01ii Introduction
Notes

TP-6103 1/01 ISafety Precautions and Instructions
Cautions and Notices
Definition of Caution, Notice, and
Important
The diagnosis and repair procedures in the GM
Powertrain Service Manual contain both general and
specific Cautions, Notices, and Importants. GM
Powertrain is dedicated to the presentation of service
information that helps the technician diagnose and
repair the systems necessary for the proper operation of
the equipment; however, certain procedures may
present a hazard to the technician if they are not
followed in the recommended manner. Cautions,
Notices, and Importants are elements designed to
prevent these hazards; however, not all hazards can be
foreseen. This information is placed at strategic
locations within the service manual and is designed to
prevent the following:
DSerious bodily injury to the technician.
DDamage to the equipment.
DUnnecessary equipment repairs.
DUnnecessary component repairs.
DImproper repair or replacement equipment
components. Any caution or notice that appears in
general information is referenced from the individual
service categories.
Caution Defined
When encountering a Caution, you will be asked to take
a necessary action or avoid a prohibited action. If a
Caution is not heeded, the following consequences may
occur:
DSerious bodily injury to the technician.
DSerious bodily injury to other technicians in the
workplace area.
DSerious bodily injury to the equipment operator if the
equipment has been improperly repaired.
Notice Defined
Notices call special attention to a necessary action or to
a prohibited action. If a Notices not heeded, the
following consequences may occur:
DDamage to the equipment.
DUnnecessary equipment repairs.
DUnnecessary component replacement.
DImproper operation or performance of the system or
component under repair.
DDamage to any systems or components that are
dependent upon the proper operation of the system or
component under repair.
DImproper operation or performance of any systems or
components that are dependent upon the proper
operation or performance of the system or
component under repair.
DDamage to fasteners, basic tools, or special tools.
DLeaks of coolant, lubricant, or other vital fluids.
Important Defined
Important statements emphasize a necessary
characteristic of a diagnostic or repair procedure.
Important statements are designed to do the following:
DClarify a procedure.
DPresent additional information for accomplishing a
procedure.
DGive insight into the reason or reasons for performing
a procedure in the manner recommended.
DPresent information that will help to accomplish a
procedure in a more effective manner.
DPresent information that gives the technician the
benefit of past experience in accomplishing a
procedure with greater ease.

TP-6103 1/01II Safety Precautions and Instructions
Moving Parts and Hot Surfaces Caution
Caution: Avoid contact with moving parts and hot
surfaces while working around a running engine in order
to prevent physical injury.
Safety Glasses Caution
Caution: Always wear safety glasses to avoid eye
damage.
Belt Drive Notice
Notice: Do not use belt dressing on the drive belt. Belt
dressing causes the breakdown of the composition of
the drive belt. Failure to follow this recommendation will
damage the drive belt.
Component Fastener Tightening Notice
Notice: Replacement components must be the correct
part number for the application. Components requiring
the use of the thread-locking compound, lubricants,
corrosion inhibitors, or sealants are identified in the
service procedure. Some replacement components
may come with these coatings already applied. Do not
use these coatings on components unless specified.
These coatings can affect the final torque, which may
affect the operation of the component. Use the correct
torque specifications when installing components in
order to avoid damage.
Fastener Notice
Notice: Use the correct fastener in the correct location.
Replacement fasteners must be the correct part number
for that application. Fasteners requiring replacement or
fasteners requiring the use of thread-locking compound
or sealant are identified in the service procedure. Do not
use paints, lubricants, or corrosion inhibitors on
fasteners or fastener joint surfaces unless specified.
These coatings affect fastener torque and joint clamping
force and may damage the fastener. Use the correct
tightening sequence and specifications when installing
fasteners in order to avoid damage to parts and
systems.
Special Fastener Notice
Notice: This bolt is designed to permanently stretch
when tightened. The correct part number fastener must
be used to replace this type of fastener. Do not use a bolt
that is stronger in this application. If the correct bolt is
not used, the parts will not be tightened correctly. The
system or the components may be damaged.