1988 PONTIAC FIERO Service Repair Manual

6A2-26 2.8 LITER V-6
2. Remove the spark plugs. Installation
3. Remove
crankshaft pulley and torsional damper. 1. Install rear main bearing oil seal in cylinder block
4. Remove oil pan and oil pump. and
rear bearing cap grooves.
5. Remove water pump, crankcase front cover, 2. Lubricate seal with engine oil. Keep oil off
camshaft sprocket and timing chain. parting
line surface.
3. Install main bearings in cylinder block and main
6. Check the connecting rod caps for cylinder
bearing caps then lubricate bearing surface with
number identification. If necessary mark them.
engine oil.
7. Remove the connecting rod caps and
push the
4. 1n;tall crankshaft, being careful not to damage
pistons to top of bores.
bearing surfaces.
8. Remove main bearing caps and lift crankshaft out 5. Recheck bearing clearances using plastigage.
of cylinder block. 6.
Apply a thin coat of anaerobic sealant
# 1052357
9. Remove rear
main bearing oil seal and main or
equivalent to rear of the block mating surface
bearings from cylinder block and main bearing or corresponding
surface or rear main cap only.
caps. Do
not allow sealer on crankshaft or seal.
7. Install main bearing caps with arrow pointing
Cleaning and Inspection toward front of engine.
8. Torque all except
#3 main bearing cap bolts to
1. Wash crankshaft in solvent and dry with
specifications. Torque
#3 main bearing cap bolts
compressed air. to 14-16
N-m (10-12 lbs. ft.) then tap end of
2. Measure
dimensions of main bearing journals and crankshaft, first rearward then forward with a
crankpins with a micrometer for out-of-round, lead
hammer. This will line up rear main bearing
taper or undersize (See Specifications). and crankshaft
thrust surfaces.
Retorque all main
3. Check
crankshaft for run-out by supporting at bearing
cap bolts to specifications.
the front and rear main bearings journals in "V" 9. Measure crankshaft
end play with a feeler gage.
blocks and check at the front and rear Force crankshaft forward and measure clearance
intermediate journals with a dial indicator (See between the front of the
#3 main bearing and
Specifications). crankshaft thrust surface.
4. Replace or recondition the crankshaft if out of 10.
Install flywheel and torque to specifications.
specifications.
SPROCKET OR GEAR REPLACEMENT
Remove crankshaft sprocket using Tool J-5825,
install using Tool J-5590.
GENERAL DATA
TYPE .................................................................................................................................... 60" V-6
DISPLACEMENT
............................................................................................................. 2.8 Liter
RPO
........................................................................................................................................... LB8
BORE ......................................................................................................................................... 89
STROKE
................................... .... ............................................................................................... 76
COMPRESSION RATIO
....................................................................................................... 8.9: 1
FIRING ORDER
.......................................................................................................... 1-2-3-4-5-6
Cylinder Bore
DIAMETER .............................................................................................................. 88.992-88.070
OUT OF ROUND
............................................................................................................. .02 Max.
TAPER-THRUST SIDE
................................................................................................. .02 Max.
Piston
CLEARANCE .................................................................................................................. .O 17-,043
Piston Ring

COMPRESSION Groove Clearance
............................................................................................................................ Top .030..070
................................................................................ Second .................................... .... .040.. 095
Gap ................................................................................................................................. Top .25..50
............................................................................................................................ Second .25..50
OIL
...................................................................................................... . Groove Clearance 0 199 Max
Gap
................................................................................................................................ 0.51-1.40
Piston Pin
DIAMETER ....................................................................................................... 22.9937-23.0015
........................................................................................................... CLEARANCE .0065-.009 1
FIT IN ROD
..................................................................................................... .0187-. 0515 Press
Camshaft
LIFT
Intake
................................................................................................................................... 6.67
Exhaust
.................................................................................................................................. 6.94
............................................................. ............................ JOURNAL DIAMETER .. 47.44-47.49
............................................................................................. JOURNAL CLEARANCE .026- . 101
Crankshaft
MAIN JOURNAL
Diameter All
67.241-67.265mm
............................................................................................................................. Taper 005 Max .
................................................................................................................ Out of Round 005
Max .
.................................................................................. MAIN BEARING CLEARANCE 04
1-.08 1
................................................................ MAIN THRUST BEARING CLEARANCE .054..084
...................................................................................... CRANKSHAFT END PLAY .06-. 2 1mm
CRANK PIN
Diameter
..................................... ... ......................................................................... 50.784-50.758
............................................................................................................................. Taper 005 Max .
............................................................................................................ Out of Round 005
Max .
.................................................... ROD BEARING CLEARANCE ......................... .. 03 5..095
................................................................................................ ROD SIDE CLEARANCE .16-. 44
Valve System
LIFTER ......................... .. ........................................................................................... Hydraulic
......................................................................................................... ROCKER ARM RATIO 1.5. 1
............................................................................... VALVE LASH 1- 1/2 Turns From Zero Lash
FACE ANGLE
........................................................................................................................... 45"
SEAT ANGLE ......................................................................................................................... 46"
....................................................................................................................... SEAT RUNOUT 05"
SEAT WIDTH
Intake
........................................................................................................................ 1.25-1.50
......................................................................................................................... Exhaust 1.60- 1.90
............................................................... STEM CLEARANCE ..................................... ... .026-. 068
VALVE SPRING
Free Length
......................................................................................................................... 48.5
Pressure N
. m
Closed
....................... .. .......................................................................................... 391 @40
Open
......................................................................................................................... 867 @30
Installed Height
........................................................................................................................ 40
DAMPER
........................................................................................................................... Free Length 47.2

Approx. # of Coils ................................... .... ............................................................................. 4
SPECIFICATIONS
................................................................................ Camshaft Sprocket 20-35 N-m, 15-25
ft. lbs.
................................................................................... Camshaft Rear Cover 8-12 N-m, 6-9 ft. 1bs.
......................................................................... . Connecting Rod Caps 46-60 N m, 34-45
ft. lbs.
............................................................................ Torsional Damper 90-1
15 N-m, 67-85 ft. lbs.
Dist. Hold Down Bolt ..................... ..... ............................................... 27-41 N.m, 20-3 1 ft. lbs.
................................................................................. Exhaust Manifold 25-42 N.m, 19-3 1 ft. lbs.
Water
Pump
M8~1.25~70.0 ........................................................................................ 18-30 N.m, 13-22 ft. lbs.
MlOx1.5x75.0 .......................... .. ........................................................ 27-48 Nem, 20-35 ft. lbs.
Thermostat Housing ........................................................................... 18-24 N-m, 13-18 ft. lbs.
Inlet Manifold Lower
........................................................................... 18-34 N-m, 13-25 ft. lbs.
............................................ ........................ Inlet Manifold Center .. 20-30 N.m (15-22 ft. lbs.) ............................................................................ Timing Chain Damper 18-24
N . m, 14- 19 ft. lbs.
Rocker Arm Nut
........................................................................................ 6-14 N-m, 5-1 1 ft. Ibs.
Rocker Arm Covers
.................................................................................... 8-20 N-m, 7-15 ft. lbs. ........................................................................................ Spark Plugs 9.5-20.3 N-m, 7-15
ft. lbs.
Oil Pan
M8~1.25x14.0 .................................................................................... 20-30 N.m, 15-22 ft. lbs.
M6xlx16.0 ............................................................................................... 8-12 Nem, 6-9 ft. lbs.
................................................................................ Main Bearing Caps 85-
112 N. m, 63-83 ft. lbs.
Oil Pump
............................................................................................. 35-47 Nem, 25-35 ft. lbs.

V-8 ENGINE BA3-1
SECVON 6A3
TER V8 V N CODE E
TER V8 V N CODE F
TER V8 V N CODE 8
CONTENTS
GENERAL DESCRIPTION .......................... 6A3- 1
ENGINE LUBRICATION .......................... 6A3-2
ON-VEHCILE SERVICE ............................... 6A3-5
...................................... Powertrain Mounts 6A3-5
Intake Manifold ........................................... 6A3-6
Dipstick Tube .............................................. 6A3-7
Exhaust Manifold ........................................... 6A3-7
........................................ Rocker Arm Cover 6A3-8
Rocker Arm and Push Rods ...................... 6A3-8
Valve Stem Oil Seal and/or
Valve Spring
................................................ 6A3-9
Valve Lifters .................................................. 6A3- 10
............................. Cylinder Head Assembly 6A3- 1 1
...................................... Rocker Arm Studs 6A3- 14
...................................... Valve Guide Bores 6A3- 14
Valve Seats .................................................. 6A3- 14
Valves ........................................................... 6A3- 15
Torsional Damper ........................................ 6A3- 15
.
............................. Crankcase Front Cover .... 6A3- 1 5
Oil Seal (Front Cover) ................................... 6A3- 16
Camshaft ...................................................... 6A3- 16
Camshaft Bearings ............................. .. ....... 6A3- 17
Oil Pan ......................................................... 6A3- 18
..................................................... Oil Pump 6A3- 18
............................. Connecting Rod Bearings 6A3- 19
.............................................. Main Bearings 6A3-20
........................................... Rear Main Seal 6A3-22
........... Connecting Rod & Piston Assemblies 6A3-23
............................................ Cylinder Block 6A3-26
............................... Oil Filter Bypass Valve 6A3-27
.......................................... Engine Assembly 6A3-27
................................................... Crankshaft 6A3-28
..................... Sprocket or Gear Replacement 6A3-28
......................................... SPECIFICATIONS 6A3-28
GENERAL DESCRIPTION
CYLINDER BLOCK CAMSHAFT AND DRIVE
The cylinder block is made of cast iron and has The
cast iron camshaft is supported by 5 bearings
8 cylinders arranged in a "V" shape with 4 cylinders and
is chain driven. A steel crankshaft sprocket drives
in each bank.
5 main bearings support the crankshaft the
timing chain which in turn drives the camshaft
which is retained by bearing caps that are machined through a cast iron 'procket.
with the block for proper alignment and clearances.
Cam lobes are ground, hardened and tapered
Cylinders are completely encircled by coolant Jackets, with the high side toward the rear. This, cou~led with
CYLINDER HEAD a sphericalYface on the lifter, causes the "alve lifters to
rotate.
Camshaft bearings are lubricated through oil
The cast iron cylinder heads feature individual
holes which intersect the main oil gallery. The main oil intake and exhaust Ports for each cylinder. Valve gallery is rifle drilled down the center of the block, guides are integral, and rocker arms are retained on above the individual pressed studs.
CRANKSHAFT AND BEARINGS
The crankshaft is cast nodular iron and is
supported by five main bearings
#5 is the end thrust
bearing.
Main bearings are lubricated from oil holes which
intersect the camshaft bearings. The camshaft bearings
are fed oil by the main oil gallery which is rifle drilled
down the center of the block, above the camshaft. Two
additional oil galleries are on either side of the main oil
gallery to provide an oil supply for the hydraulic lifters.
PISTONS AND CONNECTING RODS
The pistons are made of cast aluminum alloy
using two compression rings and one oil control ring.
Piston pins are offset 1/16"
(1.6mm) toward the thrust
side (right hand side) to provide a gradual change in
thrust pressure against the cylinder wall as the piston
travels its path. Pins are Chromium steel and have
a
floating fit in the pistons They are retained in the
connecting rods by a press fit. Connecting rods are
made of forged steel. Full pressure lubrication
is
directed to the connecting rods by drilled oil passages
from the adjacent main bearing journal.

6A3-2 V-8 ENGINE
VALVE TRAIN
A very simple ball pivot-type train is used.
Motion is transmitted from the camshaft through the
hydraulic lifter and push rod to the rocker arm. The
rocker arm pivots on its ball and transmits the
camshaft motion to the valve. The rocker-arm ball is
retained by a nut.
HYDRAULIC VALVE LIFTERS
Hydraulic Valve Lifters are used to keep all parts
of the valve train in constant contact.
The hydraulic lifter assembly consists of: a roller,
the lifter body, which rides in the cylinder block boss,
a plunger, a push rod seat, a metering valve, a plunger
spring, a check ball and spring, a check ball retainer
and a push rod seat retainer.
When the lifter is riding on the low point of the
cam, the plunger spring keeps the plunger and push rod
seat in contact with the push rod.
When the lifter body begins to ride up the cam
lobe, the check ball cuts off the transfer of oil from the
reservoir below the plunger. The plunger and lifter
body then rise as a unit, pushing up the push rod and
opening the valve.
As the lifter body rides down the other side of the
cam, the plunger follows with it until the valve closes.
The lifter body continues to follow the cam to its low
point, but the plunger spring keeps the plunger in
contact with the push rod. The ball check valve will then
move off its seat and the lifter reservoir will
remain full.
INTAKE MANIFOLD
The intake manifold for those engines with
carburetors are made of cast iron or aluminum double
level design for efficient fuel distribution. An Exhaust
Gas Recirculation (EGR) port is also cast into the
manifold for the mixture of exhaust gases with the fuel
air mixture.
The intake manifold for those vehicles equipped
with
PFI is a cast aluminum unit. It centrally supports
a fuel rail with
8 fuel injectors.
EXHAUST MANIFOLDS
Two cast iron exhaust manifolds are used to
direct exhaust gases from the combustion chambers to
the exhaust system. The left hand side manifold
receives a heat shield that is used to route heated air
to the air cleaner. for better fuel vaporization during
warm-up.
COMBUSTION CHAMBERS
Combustion Chambers are cast to insure uniform
shape for all cylinders. Spark plugs are located between
the intake and exhaust valves. The contoured wedge
shape of the combustion chamber minimizes the
possibility of detonation, facilitates breathing and
provides swirling turbulence for smooth, complete
combustion.
ENGINE LUBRICATION
Full pressure lubrication through a full flow oil through drilled passages, to the camshaft and
filter, is furnished by a gear-type oil pump. The crankshaft to lubricate the bearings. The valve lifter oil
distributor, driven by a helical gear on the camshaft,
gallery feeds the valve lifters which, through hollow
drives the oil pump. The main oil gallery feeds oil,
push rods, feed the individually mounted rocker arms.

V-8 ENGINE BA3-5
ON-VEHICLE SERVICE
Fig. 6A3-3 Engine Mounts
POWERTRAIN MOUNTS
Engine mounts (fig. 6A3-3) are the
non-adjustable type and seldom require service.
Broken or deteriorated mounts should be replaced
immediately, because of the added strain placed on
other mounts and drive line components.
Checking Engine Mounts
Front Mount
Raise the engine to remove weight from the
mounts and to place a slight tension in the rubber.
Observe both mounts while raising engine. If an engine
mount exhibits:
a. Hard rubber surface covered with heat
check cracks;
b. Rubber separated from a metal plate of the
mount;
c. Rubber split through center
replace the mount. If there is relative movement
between a metal plate of the mount and its attaching
points, lower the engine on the mounts and tighten the
screws or nuts attaching the mount to the engine,
frame, or bracket.
Rear Mount
Raise the vehicle on a hoist. Push up and pull
down on the transmission tailshaft while observing the
transmission mount. If the rubber separates from the
metal plate of the mount or if the tailshaft moves up
but not down (mount bottomed out) replace the mount.
If there is relative movement between a metal
plate of the mount and its attaching point, tighten the
screws or nuts attaching the mount to the transmission
or crossmember.
Front Mount Replacement
1. Remove mount retaining bolt from below frame
mounting bracket.
2. Raise front of engine and remove
mount-to-engine bolts and remove mount. Raise
engine only enough for sufficient clearance.
Check for interference between rear of engine and
cowl panel.
3. Replace mount to engine and lower engine into
place.
4. Install retaining bolt and torque all bolts to
specifications.
Rear Mount Replacement I
1. Support transmission weight to relieve rear
mounts.
2. Remove crossmember-to-mount nuts.
3. Remove mount-to-transmission bolts, raise
transmission, then remove mount.
4. Install new mount on transmission.
5. While lowering transmission, align mount to
crossmember.
6. Torque bolts to specifications.