check engine CHEVROLET DYNASTY 1993 Service Manual

CYLINDER BLOCK, PISTON AND CONNECTING ROD ASSEMBLY SERVICE
CYLINDER BLOCK PISTONÐREMOVAL
(1) Remove top ridge of cylinder bores with a reliable
ridge reamer before removing pistons from cylinder
block. Be sure to keep tops of pistons covered
during this operation. Pistons and connecting
rods must be removed from top of cylinder block.
When removing piston and connecting rod as-
semblies from the engine, rotate crankshaft so
that each connecting rod is centered in cylinder
bore. (2) Inspect connecting rods and connecting rod caps
for cylinder identification. Identify them if necessary.
(Fig. 2) (3) Remove connecting rod cap. Install connecting
rod bolt protectors on connecting rod bolts (Fig. 3).
Push each piston and rod assembly out of cylinder
bore. Be careful not to nick crankshaft journals.
(4) After removal, install bearing cap on the mat-
ing rod.
CLEANING AND INSPECTION
(1) Clean cylinder block thoroughly and check all
core hole plugs for evidence of leaking. (2) If new core plugs are installed, see Engine Core
Oil and Cam Plugs. (3) Examine block for cracks or fractures.
Fig. 1 Cylinder Block, Piston and Connecting Rod Assembly
Fig. 2 Identify Connecting Rod to Cylinder
Fig. 3 Connecting Rod Protectors
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CYLINDER BORE INSPECTION
The cylinder walls should be checked for out- of-
round and taper with Tool C-119 (Fig. 4). If the cylinder
walls are badly scuffed or scored, the cylinder block
should be replaced. Measure the cylinder bore at three levels in direc-
tions A and B (Fig. 4). Top measurement should be
12mm (.50 inch) down and bottom measurement
should be 12mm (.50 inch.) up from bottom of bore.
Refer to (Fig. 5) for specifications.
FINISHED PISTONS
All pistons are machined to the same weight in
grams, to maintain piston balance. For cylinder bores
which have been honed, new pistons and connecting
rod assemblies are available for service.
FITTING PISTONS
Piston and cylinder wall must be clean and dry.
Piston diameter should be measured 90 degrees to
piston pin at size location shown in (Fig. 6). Cylinder
bores should be measured halfway down the cylinder
bore and transverse to the engine crankshaft center
line shown in (Fig. 4). Refer to (Fig. 5) for specifica-
tions. Pistons and cylinder bores should be measured
at normal room temperature, 70ÉF (21ÉC)
PISTON PINS
The piston pin rotates in the piston only, and is
retained by the press interference fit of the piston pin
in the connecting rod. The piston pin is not to be
removed damage to the piston may result.
FITTING RINGS
(1) Wipe cylinder bore clean. Insert ring and push
down with piston to ensure it is square in bore. The
ring gap measurement must be made with the ring
positioning at least 12mm (.50 inch) from bottom of
cylinder bore. Check gap with feeler gauge (Fig. 7).
Fig. 5 Cylinder Bore and Piston Specifications
Fig. 6 Piston Measurements
Fig. 7 Check Gap on Piston Rings
Fig. 4 Checking Cylinder Bore Size
Ä 3.3/3.8L ENGINE 9 - 115

Refer to specifications (Fig. 8).
(2) Check piston ring to groove clearance: (Fig. 9).
Refer to specification (Fig. 8).
PISTON RINGSÐINSTALLATION
(1) The No. 1 and No. 2 piston rings have a differ-
ent cross section. Install rings with manufacturers
I.D. mark facing up, to the top of the piston (Fig. 10).
CAUTION: Install piston rings in the following or-
der:
(a) Oil ring expander.
(b) Upper oil ring side rail.
(c) Lower oil ring side rail.
(d) No. 2 Intermediate piston ring.
(e) No. 1 Upper piston ring.
(2) Install the side rail by placing one end between
the piston ring groove and the expander. Hold end
firmly and press down the portion to be installed un-
til side rail is in position. Do not use a piston ring
expander. (Fig. 11). (3) Install upper side rail first and then the lower
side rail. (4) Install No. 2 piston ring and then No. 1 piston
ring (Fig. 12).
Fig. 8 Piston Ring Specifications
Fig. 9 Measuring Piston Ring Side Clearance
Fig. 10 Piston Ring Installation
Fig. 11 Installing Side Rail
Fig. 12 Installing Upper and Intermediate Rings
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(5) Position piston ring end gaps as shown in (Fig.
13). (6) Position oil ring expander gap at least 45É from
the side rail gaps but noton the piston pin center or on
the thrust direction. Staggering ring gap is important
for oil control.
INSTALLING PISTON AND CONNECTING ROD AS-
SEMBLY
(1) Before installing pistons and connecting rod as-
semblies into the bore, besure that compression ring
gaps are staggered so that neither is in line with oil
ring rail gap. (2) Before installing the ring compressor, make sure
the oil ring expander ends are butted and the rail gaps
located as shown in (Fig. 14).
(3) Immerse the piston head and rings in clean
engine oil, slide the ring compressor, over the piston
and tighten with the special wrench. Be sure position
of rings does not change during this operation. (4) Install connecting rod bolt protectors on rod
bolts. (Fig. 3) (5) Rotate crankshaft so that the connecting rod
journal is on the center of the cylinder bore. Insert
rod and piston into cylinder bore and guide rod over
the crankshaft journal. (6) Tap the piston down in cylinder bore, using a
hammer handle. At the same time, guide connecting
rod into position on connecting rod journal. (7) The notch or groove on top of piston must be
pointing toward front of engine (Fig. 15). (8) Install rod caps. Install nuts on cleaned and
oiled rod bolts and tighten nuts to 54 N Im (40 ft. lb.)
Plus 1/4 turn.
Fig. 15 Piston I.D. Notches
Fig. 16 Checking Connecting Rod Bearing Clearance
Fig. 13 Piston Ring End Gap Position
Fig. 14 Installing Piston
Ä 3.3/3.8L ENGINE 9 - 117

CONNECTING RODS
INSTALLATION OF CONNECTING ROD BEAR- INGS
Fit all rods on one bank until complete.
The bearing caps are not interchangeable and should
be marked at removal to insure correct assembly. The bearing shells must be installed with the tangs
inserted into the machined grooves in the rods and
caps. Install cap with the tangs on the same side as the
rod. Limits of taper or out-of-round on any crankshaft
journals should be held to .025mm (.001 inch). Bear-
ings are available in .025mm (.001 inch), .051mm (.002
inch),.076mm (.003 inch), .254mm (.010 inch) and
.305mm (.012 inch) undersize. Install the bearings
in pairs. Do not use a new bearing half with an
old bearing half. Do not file the rods or bearing
caps. (1) Follow procedure specified in the Standard Ser-
vice Procedure Section for Measuring Main Bearing
Clearance and Connecting Rod Bearing Clearance
(Fig. 16). The rod bearing bolts should be examined be-
fore reuse. If the threads are necked down the
bolts should be replaced (Fig. 19). Necking can be checked by holding a scale or straight
edge against the threads. If all the threads do not
contact the scale the bolt should be replaced. (2) Before installing the nuts the threads should be
oiled with engine oil. (3) Install nuts on each bolt finger tight then alter-
nately torque each nut to assemble the cap properly. (4) Tighten the nuts to 54 N Im PLUS 1/4 turn (40 ft.
lbs. PLUS 1/4 turn). (5) Using a feeler gauge, check connecting rod side
clearance (Fig. 17). Refer to (Fig. 18) for specifications.
CRANKSHAFT SERVICE
CRANKSHAFT MAIN BEARINGS
Bearing caps are not interchangeable and should
be marked at removal to insure correct assembly.
(Fig. 1) Upper and lower bearing halves are NOT in-
terchangeable. Lower main bearing halves of 1, 3
and 4 are interchangeable. Upper main bearing
halves of 1, 3 and 4 are interchangeable.
CRANKSHAFT MAIN JOURNALS
The crankshaft journals should be checked for ex-
cessive wear, taper and scoring. (Fig. 6) Limits of
taper or out-of-round on any crankshaft journals
should be held to .025mm (.001 inch). Journal grind-
ing should not exceed .305mm (.012 inch) under the
standard journal diameter. Do NOT grind thrust
faces of Number 2 main bearing. Do NOT nick crank
pin or bearing fillets. After grinding, remove rough
edges from crankshaft oil holes and clean out all pas-
sages.
CAUTION: With the nodular cast iron crankshafts
used it is important that the final paper or cloth pol-
ish after any journal regrind be in the same direc-
tion as normal rotation in the engine.
Upper and lower Number 2 bearing halves are
flanged to carry the crankshaft thrust loads and are
NOT interchangeable with any other bearing halves
in the engine (Fig. 2). All bearing cap bolts removed
during service procedures are to be cleaned and oiled
Fig. 18 Connecting Rod Specifications
Fig. 19 Check for Stretched (Necked) Bolts
Fig. 17 Checking Connecting Rod Side Clearance
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before installation. Bearing shells are available in
standard and the following undersizes: 0.025mm (.001
inch), .051mm (.002 inch), .076mm (.003 inch), .254mm
(.010 inch), and .305mm (.012 inch). Never install an
undersize bearing that will reduce clearance below
specifications.
REMOVAL (1) Remove oil pan and identify bearing caps before
removal. (2) Remove bearing caps one at a time. Remove
upper half of bearing by inserting Special Main Bear-
ing Tool C-3059. (Fig. 3) into the oil hole of crankshaft. (3) Slowly rotate crankshaft clockwise, forcing out
upper half of bearing shell.
INSTALLATION Only one main bearing should be selectively
fitted while all other main bearing caps are prop-
erly tightened. When installing a new upper bearing shell, slightly
chamfer the sharp edges from the plain side. (1) Start bearing in place, and insert Main Bearing
Tool C-3059 into oil hole of crankshaft (Fig. 3). (2) Slowly rotate crankshaft counter-clockwise slid-
ing the bearing into position. Remove Special Main
Bearing Tool C-3059. (3) Install each main cap and tighten bolts finger
tight. (4) Tighten number 1, 3 and 4 main cap bolts to 41
N Im + 1/4 Turn (30 ft. lbs.+ 1/4 Turn).
(5) Rotate the crankshaft until number 6 piston is
at TDC. (6) To ensure correct thrust bearing alignment the
following procedure must be done: (a) Move crankshaft all the way to the rear of its
travel. (b) Then, move crankshaft all the way to the
front of its travel. (c) Wedge a appropriate tool between the rear of
the cylinder block and rear crankshaft counter-
weight. This will hold the crankshaft in it's most
forward position. (d) Tighten the #2 Thrust Bearing cap bolts to
41 N Im + 1/4 Turn (30 ft. lbs.+ 1/4 Turn). Remove
the holding tool.
CHECKING CRANKSHAFT END PLAY
(1) Mount a dial indicator to front of engine, locat-
ing probe on nose of crankshaft (Fig. 4). (2) Move crankshaft all the way to the rear of its
travel. (3) Zero the dial indicator.
(4) Move crankshaft all the way to the front and
read the dial indicator. Refer to (Fig. 5) for specifica-
tion.
CRANKSHAFT END PLAY CHECKÐOPTIONAL
(1) Move crankshaft all the way to the rear of its
travel using a lever inserted between a main bearing
Fig. 3 Removing and Installing Upper Main Bearing With Special Tool C-3059Fig. 1 Main Bearing Cap Identification
Fig. 2 Main Bearing Identification
Ä 3.3/3.8L ENGINE 9 - 119

cap and a crankshaft cheek using care not to damage
any bearing surface. Do notloosen main bearing cap.
(2) Use a feeler gauge between number 2 thrust
bearing and machined crankshaft surface to deter-
mine end play. Refer to (Fig. 5) for specification.
CRANKSHAFT OIL CLEARANCE
(1) Measure the journal outside diameter as shown
in (Fig. 6). Refer to specification (Fig. 5).
PLASTIGAGE (OIL CLEARANCE) MEASUREMENT
(1) Remove oil from journal and bearing shell.
(2) Install crankshaft.
(3) Cut plastigage to same length as width of the
bearing and place it in parallel with the journal axis
(Fig. 7). (4) Install the main bearing cap carefully and
tighten the bolts to specified torque.
CAUTION: Do not rotate crankshaft or the plasti-
gage will be smeared.
(5) Carefully remove the bearing cap and measure
the width of the plastigage at the widest part using
the scale on the plastigage package (Fig. 7). Refer to
specification (Fig. 5) for proper clearances. If the
clearance exceeds the specified limits. Replace the
main bearing(s) and if necessary have the crankshaft
machined to next undersize. Also see Measuring
Main and Connecting Rod Bearing Clearance in
Standard Service Procedures.
CAUTION: Do not rotate crankshaft or the Plasti-
gage may be smeared.
Fig. 4 Checking Crankshaft End Play
Fig. 5 Crankshaft specification
Fig. 6 Measure Crankshaft Journal O.D.
Fig. 7 Measuring Bearing Clearance with Plastigage
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(7) Place a straightedge across the face of the CCC,
between bolt holes. If a feeler gauge of .102mm (.004
inch) or more can be inserted between rotors and the
straightedge, replace pump assembly (Fig. 12). ONLY
if rotors are in specs. (8) Inspect oil pressure relief valve plunger for scor-
ing and free operation in its bore. Small marks may be
removed with 400-grit wet or dry sandpaper. (9) The relief valve spring has a free length of
approximately 49.5mm (1.95 inches) it should test
between 19.5 and 20.5 pounds when compressed to
34mm (1-11/32 inches). Replace spring that fails to
meet specifications (Fig. 5).
(10) If oil pressure is low and pump is within speci-
fications, inspect for worn engine bearings or other
reasons for oil pressure loss.
OIL PUMP ASSEMBLY AND INSTALLATION
(1) Assemble pump, using new parts as required.
Install the inner rotor with chamfer facing the
cast iron oil pump cover. (2) Tighten cover screws to 12 N Im (105 in. lbs.). (3) Prime oil pump before installation by filling ro-
tor cavity with engine oil. (4) Install chain case cover slowly refer to Timing
Chain Cover Installation of this section.
Fig. 9 Measuring Inner Rotor Thickness
Fig. 10 Measuring Outer Rotor Clearance in Housing
Fig. 11 Measuring Clearance Between Rotors
Fig. 7 Checking Oil Pump Cover Flatness
Fig. 8 Measuring Outer Rotor Thickness
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CHECKING ENGINE OIL PRESSURE
Check oil pressure using gauge at oil pressure
switch location. Oil pressure should be 34.47 kPa ( 5
psi.) at idle or 205 to 551 kPa (30 to 80 psi.) at 3000
RPM. (1) Remove pressure sending unit and install oil
pressure gauge (Fig. 13).
CAUTION: If oil pressure is 0 at idle, Do Not Run
engine at 3000 RPM .
(2) Warm engine at high idle until thermostat
opens.
OIL FILTER
CAUTION: When servicing the oil filter (Fig. 16)
avoid deforming the filter can by installing the re-
move/install tool band strap against the can-to-base
lockseam. The lockseam joining the can to the base
is reinforced by the base plate.
(1) Using Tool C-4065, unscrew filter from base
and discard (Fig. 14). (2) Wipe base clean, then inspect gasket contact
surface. (3) Lubricate gasket of new filter with clean en-
gine oil. (4) Install and tighten filter to 20 N
Im (15 ft. lbs.)
torque after gasket contacts base. Use filter wrench
if necessary. (5) Start engine and check for leaks.
Fig. 12 Measuring Clearance Over RotorsFig. 13 Checking Oil Pump Pressure
Fig. 14 Oil Filter
Ä 3.3/3.8L ENGINE 9 - 125

CLEANING AND INSPECTION
(1) Discard gaskets and clean all gasket surfaces
on both manifolds and on cylinder head. (2) Test gasket surfaces of manifolds for flatness
with a straight edge. Surfaces must be flat within
0.15mm per 300mm (.006 in. per foot) of manifold
length. (3) Inspect manifolds for cracks and distortion.
INSTALLATION
(1) Install a new intake and exhaust manifold gas-
ket. Coat steel gasket lightly with Gasket Sealer on
manifold side. Do notcoat composition gasket with
(any) sealer. (2) Set exhaust manifold in place. Tighten retain-
ing nuts starting at center and progressing outward
in both directions to 23 N Im (200 in. lbs.) torque. Re-
peat this procedure until all nuts are at specified
torque. (3) Set intake manifold in place.
(4) Raise vehicle and tighten retaining screws
starting at center and progressing outward in both
directions to 23 N Im (200 in. lbs.) torque (Fig. 3). Re-
peat this procedure until all screws are at specified
torque. (5) Reverse removal procedures 1-9 for installation.
(6) With the DRBII Scan Tool use ASD Fuel Sys-
tem Test to pressurize system to check for leaks.
CAUTION: When using the ASD Fuel System Test,
the Auto Shutdown (ASD) relay will remain ener-
gized for 7 minutes or until the ignition switch is
turned to the OFF position, or Stop All Test is se-
lected.
INTAKE AND EXHAUST MANIFOLDSÐFLEXIBLE
FUEL ENGINE
INTAKE MANIFOLD
The manifold is die-cast aluminum with upper ple-
num and 4 tubes lower runners. These attach to the
cylinder head, with each runner leading directly to a
cylinder. The manifold is also machined for fuel rail attach-
ment and injector installation. The throttle body is
installed on the upper plenum of the manifold.
EXHAUST MANIFOLD
All high strength iron casting that intermesh with
the intake manifold. For standard engines a four
branch design collects and directs exhaust gases to
the conical (articulated joint connection) outlet.
INTAKE/EXHAUST MANIFOLDS
SERVICEÐFLEXIBLE FUEL ENGINES
Intake and exhaust manifolds use a one piece gas-
ket. Service procedures requiring removal and instal-
lation of either must include both manifolds.
SERVICE PRECAUTIONS
Methanol is more toxic than gasoline. Always re-
lease fuel system pressure before servicing fuel sys-
tem components and wear methanol resistant gloves
and eye protection. Avoid breathing methanol vapors or ingesting
methanol. Headaches, dizziness and even uncon-
sciousness could result from breathing these vapors.
Serious injury, blindness and even death could result
from ingesting methanol. Methanol vapors are extremely flammable and can
travel along the ground. Service vehicles in well ven-
tilated areas and avoid ignition sources. Never
smoke while servicing the vehicle. Do not allow methanol to contact skin. Prolonged
contact with methanol can cause dry skin or an al-
lergic skin reaction. Also, prolonged contact could re-
sult in absorption through the skin.
FUEL SYSTEM PRESSURE RELEASE PROCEDURE
WARNING: RELEASE FUEL SYSTEM PRESSURE
BEFORE SERVICING FUEL SYSTEM COMPONENTS.
WEAR METHANOL RESISTANT GLOVES AND EYE
PROTECTION WHILE SERVICING THE FUEL SYS-
TEM.
(a) Disconnect negative cable from battery.
(b) Remove fuel filler cap.
(c) Remove the protective cap from the fuel pres-
sure test port on the fuel rail (Fig. 4).
(d) Place the open end of fuel pressure release
hose, tool number C-4799-1, into an approved gas-
oline container. Connect the other end of hose
C-4799-1 to the fuel pressure test port (Fig. 5).
Fuel pressure will bleed off through the hose into
the gasoline container. Fuel gauge C-4799-A con-
tains hose C-4799-1.
Fig. 4 Fuel Pressure Test Port
Ä EXHAUST SYSTEM AND INTAKE MANIFOLD 11 - 7