MAINTENANCE AND LUBRICATION OB-5
Throttle linkage inspection -- Inspect for inter-
ference, binding, damaged or missing parts.
Engine drive belts inspection - Inspect all
belts for cracks, fraying and wear. Adjust or replace as
needed.
Rear axle service (if equipped) - Check gear
lubricant level and add if needed. For cars equipped with a
limited slip rear axle, fluid does not require changing
(except Caprice and Corvette
- change fluid and required
additive at first
7,500 miles (12 500 km). See your
Owner's Manual or "Recommended Fluids
& Lubricants
Chart" in this section.
IF YOU USE YOUR GAR TO PULL A TRAILER,
CHANGE GEAR LUBRICANT EVERY 7,500 MILES
(12 500 KM).
NOTICE: A large loss in this system may indicate a
problem. Have it inspected and repaired at once.
Power antenna - Clean and then lubricate power
antenna mast. The proper lubricant as shown in Figure
OB-2 should be used.
AT LEAST ONCE A YEAR
Lap and shoulder belts condition and opera-
tion
- Inspect belt system, including webbing, buckles,
latch plates, retractors, guide loops and anchors.
Moveable head restraint operation - On cars
with moveable restraints, make sure restraints stay in the
desired position. (See adjustment instructions in your
Owner's Manual.)
Seatback latch and recliner operation on
cars equipped
with recliner seat --- Be sure seat-
backs latch on those cars with folding seats using mechan-
ical latches. Make sure the recliner is holding by pushing
and pulling on the top of the
seatback while it is reclined.
See your Owner's Manual for seat operating information.
Spare tire and jack storage- Be alert to rattles
in rear of car. Make sure the space tire, all jacking equip-
ment, any tire inflator and any covers or doors are securely
stowed at all times. Oil jack ratchet or screw mechanism
after each use.
Key lock service - Lubricate key lock cylinder at
least annually.
Body lubrication service - Lubricate all body
door hinges including the tailgate or hatchback lid (if
equipped). Also lubricate the body hood, fuel door and
rear compartment hinges and latches including interior
glove box and counsel doors, and any folding seat
hardware.
"Fansmissionltransaxle neutral or clutch
starl switch operation
CAUnON: Before pedorming the follow-
ing safety switch check, be sure to have
enough room around the car. Then, firmly
apply both the parking brake (see your
Owner's Manual for procedure) and the
regular brakes. Do not use the accelerator pedal.
If the engine
starls, be ready to turn
off the ignition promptly. Take these pre-
cautions because the car could move
without warning and possibly cause per-
sonal injury or properly damage. On auto-
matic transmissionltransaxle cars, try to
starl the engine in each gear. The starler
should crank only in "Park" or "Neutral."
On manual transmissionltransaxle cars,
place the
shiR lever in "Neutral," push the
clutch halfway and try to starl. The starler
should crank only when the clutch is fully
depressed.
Steering column lock operation
- While
parked, try to turn key to "Lock" in each gear range. The
key should turn to "Lock" only when gear is in "Park" on
automatic or "Reverse" on manual
transmissionltransax-
le. On cars with key release lever, try to turn key toULock"
without depressing the lever. The key should turn to
"Lock" only with the key lever depressed. On all vehicles,
the key should come out only in "Lock."
Parking brake and transmissionltransaxle
"Park" mechanism operation
CAUT1ON:Before checking the holding
ability of the parking brake and automatic
transmissionltransaxle "Park" mecha-
nism, park on a fairly steep hill with
enough room for movement in the down-
hill direction. To reduce the risk of person-
al injury or property damage, be prepared
to apply the regular brakes promptly if the
car begins to move.
To check the parking brake, with the engine running and
transmission/transaxle in "Neutral." slowly remove foot
pressure from the regular brake pedal (until the car is held
by only the parking brake).
To check the automatic transmissionltransaxle "Park"
mechanism holding ability, release all brakes after shift-
ing the transmissionltransaxle to "Park."
ljnderbody flushing - At least every spring,
tlush from the underbody with plain water any corrosive
materials used for ice and snow removal and dust control.
Take care to thoroughly clean any areas where mud and
other debris can collect.
Sediment packed in closed areas
of the vehicle should be loosened before being flushed.
Engine cooling system service - Inspect
coolant and freeze protection. If dirty or rusty, drain, flush
and refill with new coolant. Keep coolant
at the proper
mixture as specified in your Owner's Manual. This pro-
vides proper freeze protection. corrosion inhibitor level
and engine operating temperature. Inspect hoses and re-
place if cracked. swollen or deteriorated. Tighten hose
clamps. Clean outside of radiator and air conditioning
condensor. Wash radiator filler cap and neck.
To help
ensure proper operation. a pressure test of both the cooling
system and cap is also recommended. (See maintenance
schedule charts in Figure
OB-l for the recommended
coolant change interval.)
HEATING AND VENTILATION 1A-5
@ INSUFFICIENT HEATING OR DEFROST lNG
OF THE HEATER
IF PROBLEM
NOT RESOLVED THEN
HECK FOR AIRFLOW OUT DEFROSTER
VENT OUTLETS
INSTALL THE RADIATOR CAP. WITH ENGINE WARM,
DRIVE THE VEHICLE AT
48 KPH(3OMPH). WITH A THER-
MOMETER, CHECK THE AMBIENT AIR TEMPERATURE
CONTINUED AT TOP OF NEXT PAGE
Fig. 7 Insufficient Heating or Defrosting Diagnosis Procedure (7 of 2)
ENGINE GENERAL INFORMATION 6-1
SECTION 6
NE GENERAL NFORMAT
Description ............................................................... 6 TBI ...................................... .. ...... 6E2 ................ Engine Mechanical Multi Port Fuel Injection (MPFI) 6E3 -
............................................... 2.8L V-6 ....................................................... 6A2 Exhaust Systems 6F
5.OL V-8 ......................................................... 6A3 ~~~~~~l ~~f~~~~ti~~ ..................................... 6-2
............................ Engine Cooling ...................................................... 6B Engine Performance Diagnosis 6-3 ............................. Engine Fuel 6C Engine Mechanical Diagnosis
6-3 ........................................................... ................................... Engine Knock Diagnosis 6-4
Engine Electrical ................................................... 6D Compression Test ...................................... ... 6-5
................... Driveability and Emission Controls ...................... 6E Oil Leak Detection .. ..................... 6-5
ALL NEW GENERAL MOTORS VEHICLES ARE CERTIFIED BY THE UNITED STATES
ENVIRONMENTAL PROTECTION AGENCY AS CONFORMING TO THE REQUIREMENTS OF
THE REGULATIONS FOR THE CONTROL OF AIR POLLUTION FROM NEW MOTOR VEHICLES.
THlS CERTIFICATION IS CONTINGENT ON CERTAIN ADJUSTMENTS BEING SET TO
FACTORY STANDARDS. IN MOST CASES, THESE ADJUSTMENT POINTS EITHER HAVE
BEEN PERMANENTLY SEALED AND/OR MADE INACCESSIBLE TO PREVENT
INDISCRIMINATE OR ROUTINE ADJUSTMENT IN THE FIELD. FOR
THlS REASON, THE
FACTORY PROCEDURE FOR TEMPORARILY REMOVING PLUGS, CAPS, ETC., FOR
PURPOSES OF SERVICING THE PRODUCT MUST BE STRICTLY FOLLOWED AND,
WHEREVER PRACTICABLE, RETURNED TO THE ORIGINAL INTENT OF THE DESIGN.
DESCRIPTION OF: SECTION 6
SECTION 6A - ENGINE MECHANICAL used for each carburetor. TBI units are described in
This section general contains information on the Section 6E.
mechanical parts of the engine, such as block,
crankshaft, pistons, valve train, and camshaft, that are
common to most engines. Overhaul procedures,
removal and replacement procedures, and
s~ecifications are also covered. Subsections furnish
detailed information on each specific engine. Service
SECTION 6D - ENG l N E ELECTRICAL
information is also given that relates to that engine's
use in each
Carline. Specific subsections are: Items
covered in this section are battery,
generator, starter, primary and secondary ignition,
6A2
- 2.8L V-6 Engine
engine wire harness, spark plugs and wires, and
6A3
- 5.OL V-8 Engine
ignition switch.
SECTION 6B - ENGINE COOLING
Engine cooling system components such as
radiator, water pump, thermostat, and cooling fan, are
covered in this section. Accessory drive belts are also
covered, along with cooling system capacities.
SECTION 6C - FUEL SYSTEM
This section contains information on all the parts
of the fuel system
except the carburetor, or Throttle
Body Injection unit (TBI) itself. Items covered are fuel
tank, fuel pump, and fuel lines. Specific subsections are
SECTION 6E - DRIVEABILITY AND EMISSIONS
This section covers emission control systems
general information, and diagnostic procedures which
will lead to repairing performance and driveability
related problems for gasoline engine equipped vehicles.
All emission components are covered, as well as all
removal and replacement procedures. Instructions on
use of special tools are also given. Specific sections are:
6E
- Driveability and Emissions
6E2
- Fuel Injection (TBI)
6-4 ENGINE GENERAL INFORMATION
Bent connecting rod.
HEAVY KNOCK H0"FVVI"F TORQUE APPLIED
Broken balancer, or pulley hub. Replace parts as e Exhaust system grounded. Reposition as
necessary. necessary.
Loose torque converter bolts. Flywheel
cracked.
e Excessive main bearing clearance. Replace as
Accessory belts too tight or nicked. Replace
necessary.
and/or tension to specs as necessary.
e Excessive rod bearing clearance. Replace as
necessary.
LIGHT KNOCK HOT
Detonation or spark knock. Check operation of e Loose torque converter bolts.
EST or ESC (See Section
6D or 6E). Check e Exhaust leak at manifold. Tighten bolts and/or
engine timing and fuel quality.
replace gasket.
8 Excessive rod bearing clearance. Replace
bearings as necessary.
KNOCKS ON INITIAL START-UP BUT ONLY LASTS A FEW SECONDS
Noisy mechanical fuel pump. Replace pump.
When the engine is stopped, some valves
will be open. Spring pressure against lifters
Improper oil viscosity. Install proper oil viscosity will
tend to bleed lifter down. Attempts to
for expected temperatures. See Owner's Manual. repair
should be made only if the problem
is consistent.
Hydraulic lifter bleed down. Clean, test and @ Excessive crankshaft end clearance. Replace
replace as necessary. crankshaft
thrust bearing.
@ Excessive front main bearing clearance. Replace
worn parts.
KNOCKS AT IDLE HOT
Loose or worn drive belts. Tension and/or @ Excessive piston pin clearance. Ream and install
replace as necessary. oversize pins. (VIN R and 2) or replace piston
A/C Compressor or generator bearing. Replace and
pin.
as necessary.
e Connecting rod alignment. Check and replace
rods as necessary.
Noisy mechanical fuel pump. Replace pump.
8 Insufficient piston to bore clearance. Hone bore
Valve train. Replace parts as necessary. and
fit new piston.
@ Loose crankshaft balancer. Torque and/or
Improper oil viscosity. Install proper viscosity oil
replace worn parts.
for expected temperature4 See Owner" e Piston pin offset to wrong side. Install correct
ENGINE OVERHEATS
Coolant system leak, oil cooler system leak, or
2. Belt slipping or damaged. Replace tensioner, or
coolant recovery system not operating. Check for belt, as required.
leaks and correct as required. Check coolant
3. Thermostat stuck closed. Check and replace if
recovery tank, hose and radiator cap.
required.
4. Electrical cooling fan operation. See the
ELECTRICAL TROUBLESHOOTING
MANUAL.
5. Head gasket leaking. Check and repair as
required.
2.8 LITER V-6 6A2-9
INTAKE MANIFOLD (FIGURE 6A2-7)
Removal
Disconnect battery.
Remove air cleaner.
Drain coolant.
Refer to Section 6E3 for removal of the following
PFI sub-assemblies.
e Plenum
e Fuel Rail
e Runner
Disconnect spark plug wires at spark plugs.
Disconnect wires at coil.
Remove distributor cap and spark plug wires.
Mark distributor position and remove hold down
bracket.
Remove distributor.
Remove air management hose, manual
transmission only.
Disconnect emission canister hoses. Remove pipe
bracket (front left valve cover).
Remove left valve cover.
Remove air management bracket, manual
transmission only.
Remove right valve cover.
Remove upper radiator hose.
Disconnect heater hose.
Disconnect coolant switches.
Remove manifold bolts.
Remove manifold. Discard manifold gaskets and
remove loose RTV from front and rear ridges of
cylinder case.
Installation
When installing intake gaskets, notice that the
gaskets are marked Right Side and Left Side
(carbureted only). Use them only as indicated to
maintain designed efficiency of this engine.
1. Make
sure that no oil or water is present on
surface when new RTV is applied. Place a 5mm
diameter
(3/16") bead of RTV, # 1052917 or
equivalent, on each ridge.
2. Install
new intake gaskets on cylinder heads.
Hold in place by extending ridge RTV bead up
6mm onto the gasket ends. The new intake
gaskets will have to be cut, where indicated, to
install behind push rods. Cut only those areas
that are necessary.
3. Install intake
manifold on engine. Make sure
areas between case ridges and intake are
completely sealed.
4. Install manifold retaining bolts and nuts and
torque in the sequence shown in Figure 6A2-7.
5. Install heater and radiator hose to manifold.
6. Install rocker covers as previously outlined.
7. Connect coolant switches.
8. Install air management bracket.
9. Install pipe bracket (front left rocker cover).
10. Install distributor, distributor cap and retaining
nut. Do not tighten.
11. Refer to Section 6E3 for installation of PFI
sub-assemblies removed. 12.
Connect
necessary wires and hoses.
13. Fill cooling system with
the proper mixture of
ethylene glycol anti-freeze and water. Do not
install radiator cap.
14. Start
engine, set intitial timing. After set, torque
distibutor hold down clamp bolt to 34
N-m (25
lb. ft.). Recheck timing after torquing bolt.
15. Let engine
run until radiator upper hose becomes
hot (thermostat open).
16. With
engine idling, add coolant to radiator, if
necessary, until level reaches bottom of filler
neck.
17. Install
radiator cap, making sure arrows on cap
line up with overflow tube.
Figure 6A2-8 Exhaust Manifold
EXHAUST MANIFOLD (FIGURE 6A2-8)
Removal (Left)
1. Disconnect battery.
2. Raise vehicle.
3. Disconnect exhaust pipe.
4. Remove
(4) rear manifold bolts and (1) nut.
5. Lower vehicle.
6. Disconnect air management, hoses and wires.
7. Remove power steering and fuel line bracket.
8. Remove manifold.
Installation (Left)
1. Clean mating surfaces on manifold and head,
then install manifold in position and install bolts.
2. Torque
manifold bolts to 34
N.m (25 ft. lbs.).
3. Install power steering bracket.
4. Raise vehicle.
5. Install exhaust pipe.
6. Lower vehicle.
7. Connect battery.
Removal (Right)
1. Disconnect battery.
2. Raise vehicle.
3. Disconnect exhaust pipe.
4. Lower vehicle.
2.8 LITER V.6 6A2-15
18-30 N.m (13-22 FT. LBS.)
I 11 47-48 N.m (20-35 FT. LBS.) I
Figure 6A2-17 Water Pump/Front Cover Orientation
CRANKCASE FRONT COVER
Removal
1. Raise engine.
2. Remove oil pan.
3. Lower vehicle.
4. Remove water pump as outlined in Section 6B.
5. If A/C equipped, remove compressor from
mounting bracket and lay aside. Then remove
compressor mounting bracket.
6. Remove torsional damper as previously outlined.
7. Disconnect lower radiator hose at front cover and
heater hose at water pump.
8. Remove remaining front cover bolts and remove
cover.
Installation
1. Install new gasket. When installing new gasket,
be sure sealing surfaces are clean. Care should be
taken not to damage sealing surfaces.
2. Place front cover on the engine, install stud bolt
and bolts, install water pump as outlined in
Section 6B, install retaining bolts and nut and
torque to specifications.
3. Connect lower radiator hose to front cover.
Torque clamps to
3.5 N-m (30 lb. in.).
4. Install torsional damper as previously outlined.
5. Install water pump as outlined in Section 6B.
6. If A/C equipped, install compressor mounting
bracket and install compressor.
7. Raise vehicle.
8. Inspect oil pan gasket replace if necessary.
9. Install oil pan.
10. Lower vehicle.
11. Install serpentine belt.
12. Fill cooling system. Leave radiator cap off.
13. Connect battery negative cable and start engine.
14. Run engine until upper radiator hose becomes
hot (thermostat open).
15. Check coolant level and add as necessary.
16. Install radiator cap, making sure arrows on cap
line up with overflow tube.
OIL SEAL (FRONT COVER)
Replacement
With Cover Removed
1. With cover removed, pry oil seal out of cover
from the front with a large screw driver.
2. Install new seal so that open end of the seal is
toward the inside of cover and drive it into
position with Tool
5-23042. Support cover at seal
area. Pre-lube seal with engine oil prior to
installation of torsional damper.
With Cover Installed
1. With torsional damper removed, pry seal out of
cover from the front with a large screw driver,
being careful not to damage the surface on the
crankshaft.
2. Install new seal so that open end of seal is toward
the inside of cover and drive it into position with
To01 5-23042.
Figure 6A2-18 Timing Chain and Sprockets
TIMING CHAIN AND SPROCKET
Removal
1. Remove crankcase front cover as previously
outlined.
2. Place #1 piston at top dead center with the
marks on the camshaft and crankshaft sprockets
aligned (#4 firing).
3. Remove camshaft sprocket bolts and remove
camshaft sprocket and chain (Figure
6A2- 18).
Sprocket is a light fit on camshaft.
If sprocket
does not come off easily, a light blow on the lower
edge of the sprocket (with a plastic mallet) should
dislodge the sprocket.
Installation
1. Install timing chain on camshaft sprocket, lube
thrust surface with Molykote or its equivalent.
Hold the sprocket vertically with the chain
hanging down and align the marks on the
camshaft and crankshaft sprockets. (Refer to
Figure
6A2- 19).
2.8 LITER V-6 6A2-25
Fitting
1. Select rings comparable in size to the piston being
used.
2. Slip
the compression ring in the cylinder bore;
then press the ring down into the cylinder bore
about 6mm above ring travel. Be sure ring is
square with cylinder wall.
3. Measure the space or gap between the ends of the
ring with a feeler gage (Figure
6A2-33).
4. If
the gap between the ends of the ring is below
specifications, remove the ring and try another
for fit.
5. Fit each compression ring to the cylinder in
which it is going to be used.
6. If the pistons have not been cleaned and inspected
as previously outlined, do so.
7. Slip the outer surface of the top and second
compression ring into the respective piston ring
groove and roll the ring entirely around the
groove (Figure
6A2-34). If binding occurs at any
point, the cause should be determined. If there is
a ring groove, remove by dressing with a fine cut
file. If the binding is caused by a distorted ring,
check a new ring.
Installation
1. Install oil ring spacer in groove being sure ends
are butted and not overlapped.
2. Hold
spacer ends butted and install lower steel oil
ring rail.
3. Install upper
steel oil ring rail with gap staggered.
4. Flex
the oil ring assembly to make sure ring is
free. If binding occurs, the cause should be
detemined. If caused by ring groove, remove by
dressing groove with a fine cut file. If binding is
caused by a distorted ring, check a new ring.
5. Install second compression ring. Stagger gap
from other rings.
6. Install top compression ring with gap properly
located.
ENGINE ASSEMBLY
Removal
Disconnect battery.
Remove air cleaner.
Remove hood. Drain radiator.
Remove lower radiator hose.
Remove upper fan shroud.
Remove upper radiator hose and coolant
recovery hose.
Remove transmission cooler lines. Remove radiator.
Remove fan assembly.
Remove heater hoses.
Disconnect carburetor linkage, includes cruise
control detent cable.
Remove vacuum brake booster line.
Remove distributor cap and lay wiring aside.
Disconnect necessary wires and hoses.
Remove power steering pump and lay aside. Raise
vehicle.
Remove exhaust pipes at exhaust manifold.
Remove dust cover.
Remove converter bolts.
Disconnect starter wires.
Remove bell housing bolts.
Remove motor mount through bolts.
Disconnect fuel lines at fuel pump.
Lower vehicle. Support transmission.
Remove
A.I.R./Converter pipes bracket.
Remove engine, include removing wire from
bracket at rear left of engine.
Installation
Position engine assembly in vehicle.
Attach motor mount to engine brackets and
lower engine in place.
Remove engine lifting device.
Remove transmission floor jack.
Raise vehicle on hoist.
Install mount "through" bolts. Torque to
specifications.
Install bell housing bolts. Torque to
specifications.
On vehicles with automatic transmission, install
converter to flywheel attaching bolts. Torque to
specifications.
Install flywheel splash shield of conveter housing
cover as applicable. Torque attaching bolts to
specifications.
Install starter wires.
Connect fuel lines.
Connect exhaust pipe at manifold.
Lower vehicle on hoist.
Reinstall power steering pump, if so equipped.
Connect necessary wires and hoses.
Install radiator and fan shroud and reconnect
radiator and heater hoses.
Fill cooling system.
Fill crankcase with oil. See owner's manual for
specifications.
Install air cleaner.
Install hood.
Connect battery cables.
NOTICE: To avoid possible arcing of battery,
connect positive battery cable first.
22. Start engine, check for leaks and check timing.
CRANKSHAFT
The crankshaft can be removed while the engine
is dissasembled for overhaul, as previously outlined or
without complete disassembly.
Removal
1. With the engine removed from the vehicle,
remove the clutch assembly (if equipped) and
flywheel. Mount engine in stand and clamp
securely.
6A3-6 V-8 ENGINE
Fig. 6A3-4 Intake Manifold Installation (LO31
INTAKE MANIFOLD
Removal (TBI)
1. Disconnect battery negative cable.
2. Drain radiator and remove air cleaner.
3. Disconnect:
e Radiator upper hose and heater hose at
manifold.
e TBI linkage.
e Fuel lines
Spark plug wires (right side).
e Necessary wires and hoses.
4. Remove distributor cap and mark rotor position
with chalk, then remove distributor.
5. Remove (as required) air compressor and
brackets and cruise control servo and bracket.
6. Remove generator upper mounting bracket.
7. Remove EGR solenoids and bracket.
8. Remove vacuum brake line.
9. Remove manifold attaching bolts, then remove
manifold, discard gaskets.
10. If manifold is to be replaced, transfer:
e TBI attaching bolts, where applicable.
Thermostat with housing (use new gasket or
RTV, as applicable).
EGR Valve (use new gasket), where
applicable.
e Necessary switches and fittings.
lnstallation
1. Clean gasket and seal surfaces on manifold,
block, and cylinder heads with degreaser.
Remove all RTV that is loose or will cause
installation interference.
2. Install gaskets on cylinder heads and place a
3/16" (5mm) bead of RTV, At1052917 or
equivalent, on the front and rear ridges of the
cylinder case. Extend the bead
1/2" (13mm) up
each cylinder head to seal and retain the manifold
side gaskets. Use sealer at water passages. 3.
Install manifold and torque bolts to specifications
in the sequence outlined in
fig. 4.
4. Install (if removed) air compressor and bracket,
and cruise control servo and bracket.
5. Install distributor, positioning rotor at chalk
mark, then install distributor cap.
6. Install generator upper mounting bracket.
7. Install vacuum brake line.
8. Install EGR solenoid and bracket.
9. Connect:
Fuel lines
s Accelerator linkage at carburetor.
@ Disconnected wires and hoses.
Battery negative cable at battery.
10. Install air cleaner.
11. Fill with coolant, start engine, adjust ignition
timing
and check for leaks.
SNUG TIGHTENING SEQUENCE
WEW @
AT TIME OF INSTALUVIBN SURFACE AR- MUST BE FREE OF OIL AND 8ULlNG CQMWUIJD MUST BE Wm TO TOUCH WHEN BBLTISCRWS ARE TORQUED. APPLY SULINO GOMPOLINB
Figure 6A3-4a Intake Manifold Installation (PFI)
Removal (PFI]
1. Disconnect the negative battery cable.
2. Drain the cooling system.