1993 CHEVROLET DYNASTY checking oil

(3) Apply light coating of engine oil to the entire
circumference of oil seal lip. (4) Install seal assembly on cylinder block and
tighten bolts to 12 N Im (104 in. lbs.)
FRONT CRANKSHAFT OIL PUMP AND OIL
SEAL
(1) Install oil pump gasket and oil pump case
(Figs. 1 and 14). CAUTION: Install bolts, depending on length in lo-
cations shown in (Fig. 14).
(2) Using front crankshaft oil seal installer Special
Tool MB998306 install oil seal in oil pump (Fig. 15).
CYLINDER BLOCK
Inspect cylinder block for scratches, cracks and rust
or corrosion, and repair or replace as required.
Fig. 10 Crankshaft Main Bearing Cap
Fig. 11 Checking Crankshaft End PlayFig. 12 Install Crankshaft Rear Oil Seal
Ä 3.0L ENGINE 9 - 89

(5) Replace if out of limits.
OIL RELIEF PLUNGER
(1) Check that the oil relief plunger slides
smoothly. (2) Check for broken relief spring.
INSTALLATION
(1) Clean block and pump surfaces.
(2) Install new gasket (Fig. 7) make sure correct
length bolts are used (Fig. 6). (3) Torque bolts to 13 N Im (120 in. lbs.).
CHECKING ENGINE OIL PRESSURE
Check oil pressure using gauge at oil pressure
switch location. Oil pressure should be 41 kPa ( 6
psi.) at idle or 241 to 517 kPa (35 to 75 psi.) at 3000
RPM. (1) Remove pressure sending unit and install oil
pressure gauge. (Fig. 11)
CAUTION: If oil pressure is 0 at idle, Do Not Run
engine at 3000 RPM .
(2) Warm engine at high idle until thermostat
opens.
Fig. 7 Oil Pump Components
Fig. 8 Inner Rotor to Case
Fig. 9 Checking Clearance-Between Outer Rotor and Case
Fig. 10 Checking Rotor End Clearance
Fig. 11 Checking Oil Pump Pressure
Ä 3.0L ENGINE 9 - 93

3.3/3.8L ENGINE INDEX
page page
Camshaft .............................. 112
Camshaft BearingsÐEngine Removed From Vehicle .............................. 113
Checking Engine Oil Pressure .............. 125
Connecting Rods ........................ 118
Crankshaft Oil Seals Service ............... 121
Crankshaft Service ...................... 118
Cylinder Block, Piston and Connecting Rod Assembly Service ...................... 114
Cylinder Heads ......................... 102
Engine Assembly ........................ 101
Engine Core Oil and Cam Plugs ............ 113
Engine Lubrication System ................ 122 Engine Mounts
.......................... 99
Engine Specifications ..................... 126
General Information ....................... 98
Hydraulic Tappets ....................... 108
Installing Piston and Connecting Rod Assembly . 117
Intake Manifold Sealing ................... 104
Oil Filter .............................. 125
Oil Pan Service ......................... 122
Oil Pump Service ....................... 123
Rocker Arms and Shaft Assembly ........... 102
Timing Chain Cover, Oil Seal and Chain ...... 109
Valve Service .......................... 104
Valve Timing ........................... 109
GENERAL INFORMATION
ENGINE IDENTIFICATION NUMBER OR CODE
The engine identification number is located on the
rear of the cylinder block just below the cylinder
head (Fig. 2). ENGINE: The 3.3L (201 Cubic. Inches.) and 3.8L
(231 Cubic. Inches.) displacement engines are 60É V
type six cylinder power plant with cast iron cylinder
block and aluminum cylinder heads (Fig. 1). Firing
order for these engines is 1-2-3-4-5-6. High turbu-
lence cylinder heads allow a 8.9-1 compression ratio. CRANKSHAFT: The nodular iron crankshaft is
supported by four main bearings, with number two being the thrust bearing. Crankshaft end sealing is
provided by front and rear rubber seal. PISTONS: The pistons are cast aluminum alloy.
Three rings are used. Piston pins, press fitted into
place, join the pistons to forged steel connecting rods. CAMSHAFT: The nodular iron camshaft is
mounted in four steel backed babbitt bearings. A
thrust plate located in front of the first bearing, and
bolted to the block, controls end play. Silent timing
chain drives the camshaft. This chain is enclosed by
a cast aluminum cover which also carries a front
crankshaft seal, provides front oil pan closure, water
pump mounting.
SPECIFICATIONS
9 - 98 3.3/3.8L ENGINE Ä

INSPECTION
(1) Before cleaning, check for leaks, damage and
cracks. (2) Clean cylinder head and oil passages.
(3) Check cylinder head for flatness (Fig. 8).
(4) Inspect all surfaces with a straightedge if there is
any reason to suspect leakage. If out of flatness exceeds
.019mm (.00075 inch). times the span length in inches
in any direction, either replace head or lightly machine
the head surface. As an example, if a 12 inch span is
1mm (.004 inch) out of flat, allowable is 12 x .019mm
(.00075 inch) equals .22mm (.009 in.) This amount of
out of flat is acceptable. *Maximum of 0.2 mm (.008 inch) for grinding is
permitted.
CAUTION: This is a combined total dimension of
stock removal from cylinder head and block top
surface.
INSTALLATION
(1) Clean all surfaces of cylinder block and cylinder
heads. (2) Install new gaskets on cylinder block (Fig. 9).
The Cylinder head bolts are torqued using the
torque yield method, they should be examined
BEFORE reuse. If the threads are necked down,
the bolts should be replaced (Fig. 10).
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. (3) Tighten the cylinder head bolts 1 thru 8 in the
sequence shown in (Fig. 11). Using the 4 step torque
turn method, tighten according to the following values:
² First-All to 61 N Im (45 ft. lbs.)
² Second-All to 88 N Im (65 ft. lbs.)
² Third-All (again) to 88 N Im (65 ft. lbs.)
² Fourth + 1/4 Turn Do not use a torque wrench
for this step (4) Bolt torque after 1/4 turn should be over 122
N Im(90 ft. lbs.). If not, replace the bolt.
(5) Tighten head bolt number 9 (Fig. 11) to 33 N Im
(25 ft. lbs.) after head bolts 1 thru 8 have been tighten
to specifications. (6) Inspect push rods and replace worn or bent rods.
(7) Install push rods, rocker arm and shaft assem-
blies with the stamped steel retainers in the four
positions, tighten to 28 N Im (250 in. lbs.) (Fig. 12).
Fig. 8 Check Cylinder Head
Fig. 9 Head Gasket Installation
Fig. 10 Checking Bolts for Stretching (Necking)
Fig. 11 Cylinder Head Tightening Sequence
Ä 3.3/3.8L ENGINE 9 - 103

length of the spring to be tested is 33.34mm (1-5/16
inches). Turn table of Tool C-647 until surface is in line
with the 33.34mm (1-5/16 inch) mark on the threaded
stud and the zero mark on the front. Place spring over
stud on the table and lift compressing lever to set tone
device. Pull on torque wrench until ping is heard. Take
reading on torque wrench at this instant. Multiply this
reading by two. This will give the spring load at test
length. Fractional measurements are indicated on the
table for finer adjustments. Refer to specifications to
obtain specified height and allowable tensions. Discard
the springs that do not meet specifications.
VALVE INSTALLATION
(1) Coat valve stems with clean engine oil and insert
them in cylinder head. (2) Check valve tip to spring seat dimension A after
grinding the valve seats or faces. Grind valve tip to give
49.541 to 51.271 mm (1.950 to 2.018 inch.) over spring
seat when installed in the head (Fig. 17). Check valve
tip for scoring, if necessary, the tip chamfer should be
reground to prevent seal damage when the valve is
installed. (3) Install new cup seals on all valve stems and over
valve guides (Fig. 24). Install valve springs and valve
retainers.
(4) Compress valve springs with Valve Spring Com-
pressor Tool C-3422-B, with adapter 6412 install locks
and release tool. If valves and/or seats are re-
ground, measure the installed height of springs
dimension B, make sure measurements is taken
from top of spring seat to the bottom surface of
spring retainer. If height is greater than 1-19/32
inches, (40.6mm), install a 1/32 inch (.794mm)
spacer in head counterbore to bring spring
height back to normal 1-17/32 to 1-19/32 inch (39.1
to 40.6mm) .
REPLACE VALVE STEM SEALS OR VALVE
SPRINGS, CYLINDER HEAD NOT REMOVED
(1) Perform fuel system pressure release procedure
before attempting any repairs (2) Disconnect negative battery cable. (3) Remove Air Cleaner Cover and hose assembly.
(4) Remove Intake Manifold; Refer to
Intake/Exhaust Manifold 3.3/3.8L Engine Group 11
Exhaust System and Intake Manifolds of this manual
for removal procedure. (5) Remove cylinder head covers and spark plugs.
(6) Remove connector wire from ignition coils.
(7) Using suitable socket and flex handle at crank-
shaft pulley retaining screw, turn engine so the num-
ber 1 piston is at Top Dead Center on the compression
stroke. (8) Remove rocker arms with rocker shaft and in-
stall a dummy shaft. The rocker arms should not be
disturbed and left on shaft. (9) With air hose attached to spark plug adapter
installed in number 1 spark plug hole, apply 90 to 100
psi air pressure (620.5 to 689 kPa). This is to hold
valves into place while servicing components. (10) Using Tool C-4682 or Equivalent compress
valve spring and remove retainer valve locks and valve
spring. (11) The intake valve stem seals should be pushed
firmly and squarely over the valve guide using the
valve stem as guide. Do Not Forceseal against top of
guide. When installing the valve retainer locks, com-
press the spring only enoughto install the locks.
CAUTION:Do not pinch seal between retainer and top
of valve guide .
(12) Follow the same procedure on the remaining 5
cylinders using the firing sequence 1-2-3-4-5-6. Make
sure piston in cylinder is at TDC on the valve
spring that is being covered. (13) Remove spark plug adapter tool .
(14) Remove dummy shaft and install rocker shaft
assembly and tighten screws to 28 N Im (250 in. lbs.).
Fig. 24 Checking Valve Installed Height
Fig. 25 Installing Valve, Cup Seal, Spring and Re-
tainer
Ä 3.3/3.8L ENGINE 9 - 107

(15) Install rocker arm covers tighten screws to 14
N Im (120 in. lbs.) and connector to ignition coils.
(16) Install Intake Manifold; Refer to Intake Mani-
fold Installation 3.3/3.8L Engine, Group 11 Exhaust
System and Intake Manifold.
HYDRAULIC TAPPETS
The valve train includes roller tappet assemblies,
aligning yokes and yoke retainer. Roller tappet alignment is maintained by machined
flats on tappet body being fitted in pairs into six
aligning yokes. The yokes are secured by an alignment
yoke retainer (Fig. 26).
PRELIMINARY STEP TO CHECKING THE HY- DRAULIC TAPPETS
Before disassembling any part of the engine to cor-
rect tappet noise, read the oil pressure at the gauge.
Install a reliable gauge at pressure sending unit if
vehicle has no oil pressure gauge and check the oil level
in the oil pan. The pressure should be between 30 and
80 psi (206.8 to 551.6 kPa) at 2000 rpm. The oil level in the pan should never be above the
MAX mark on dipstick, or below the MIN mark. Either
of these two conditions could be responsible for noisy
tappets. Oil Level Check: stop engine after reach-
ing normal operating temperature . Allow 5 min-
utes to stabilize oil level, check dipstick.
OIL LEVEL TOO HIGH
If oil level is above the MAX mark on dip stick, it is
possible for the connecting rods to dip into the oil while
engine is running and create foam. Foam in oil pan
would be fed to the hydraulic tappets by the oil pump
causing them to become soft and allow valves to seat
noisily.
OIL LEVEL TOO LOW
Low oil level may allow pump to take in air which
when fed to the tappets, causes them to become soft
and allows valves to seat noisily. Any leaks on intake
side of pump through which air can be drawn will
create the same tappet action. Check the lubri- cation system from the intake strainer to the pump
cover, including the relief valve retainer cap. When
tappet noise is due to aeration, it may be intermittent
or constant, and usually more than one tappet will be
noisy. When oil level and leaks have been corrected,
engine should be operated at fast idle to allow all of the
air inside of the tappets to be bled out.
VALVE TRAIN NOISE DIAGNOSIS
To determine source of valve train noise, operate
engine at idle with cylinder head covers removed and
listen for source of the noise. Worn valve guides or cocked springs are some-
times mistaken for noisy tappets. If such is the
case, noise may be dampened by applying side
thrust on the valve spring. If noise is not appre-
ciably reduced, it can be assumed the noise is in
the tappet. Inspect the rocker arm push rod
sockets and push rod ends for wear. Valve tappet noise ranges from light noise to a heavy
click. A light noise is usually caused by excessive
leakdown around the unit plunger which will necessi-
tate replacing the tappet, or by the plunger partially
sticking in the tappet body cylinder. A heavy click is
caused either by a tappet check valve not seating, or by
foreign particles becoming wedged between the
plunger and the tappet body causing the plunger to
stick in the down position. This heavy click will be
accompanied by excessive clearance between the valve
stem and rocker arm as valve closes. In either case,
tappet assembly should be removed for inspection and
cleaning.
TAPPET REMOVAL
(1) Refer to Cylinder Head Removal of this section to
remove intake manifold and cylinder heads for access
to tappets for service. (2) Remove yoke retainer and aligning yokes.
(3) Use Tool C-4129 to remove tappets from their
bores. If all tappets are to be removed, identify tappets
to insure installation in original location. If the tappet or bore in cylinder block is scored,
scuffed, or shows signs of sticking, ream the bore
to next oversize and replace with oversize tap-
pet.
CAUTION: The plunger and tappet bodies are not
interchangeable. The plunger and valve must always
be fitted to the original body. It is advisable to work on
one tappet at a time to avoid mixing of parts. Mixed
parts are not compatible. Do not disassemble a tap-
pet on a dirty work bench.
DISASSEMBLY (FIG. 27)
(1) Pry out plunger retainer spring clip.
Fig. 26 Roller Tappets Aligning Yoke and Retainer
9 - 108 3.3/3.8L ENGINE Ä

(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
9 - 118 3.3/3.8L ENGINE Ä