1993 CHEVROLET DYNASTY oil

(15) Install hood.
(16) Connect battery.
(17) Start engine and run until operating temper-
ature is reached. (18) Adjust transmission or linkage if necessary.
ROCKER ARMS AND SHAFT ASSEMBLY
REMOVAL
(1) Remove upper intake manifold assembly. Refer
to Intake and Exhaust Manifolds, Group 11. (2) Disconnect spark plug wires by pulling on the
boot straight out in line with plug. (3) Disconnect closed ventilation system and evap-
oration control system from cylinder head cover. (4) Remove cylinder head cover and gasket.
(5) Remove four rocker shaft bolts and retainers.
(6) Remove rocker arms and shaft assembly.
(7) If rocker arm assemblies are disassembled for
cleaning or replacement. Assemble rocker arms in
their original position.Refer to (Fig. 5) for rocker arm
for positioning on the shaft.
INSTALLATION
(1) Install rocker arm and shaft assemblies with
the stamped steel retainers in the four positions,
tighten to 28 N Im (250 in. lbs.) (Fig. 5).
WARNING: THE ROCKER ARM SHAFT
SHOULD BE TORQUED DOWN SLOWLY,
STARTING WITH THE CENTERMOST BOLTS.
ALLOW 20 MINUTES TAPPET BLEED DOWN
TIME AFTER INSTALLATION OF THE
ROCKER SHAFTS BEFORE ENGINE OPERA-
TION. (2) Clean cylinder head cover gasket surface. In-
spect cover for distortion and straighten if necessary. (3) Clean head rail if necessary. Install a new gas-
ket and tighten cylinder head cover fasteners to 12
N Im (105 in. lbs.).
(4) Install closed crankcase ventilation system and
evaporation control system. (5) Install spark plug wires.
(6) Install upper intake manifold assembly. Refer to
Exhaust Systems and Intake Manifolds Group 11.
CYLINDER HEADS
The alloy aluminum cylinder heads shown in (Fig. 6)
are held in place by 9 bolts. The spark plugs are located
in peak of the wedge between the valves.
REMOVAL
(1) Drain cooling system refer to Cooling System
Group 7 for procedure and disconnect negative battery
cable. Remove intake manifold, and throttle body. Refer to
Group 11 Exhaust System and Intake Manifold. (2) Disconnect coil wires, sending unit wire, heater
hoses and by-pass hose. (3) Remove closed ventilation system, evaporation
control system and cylinder head covers. (4) Remove exhaust manifolds.
(5) Remove rocker arm and shaft assemblies. Re-
move push rods and identify to insure installation
in original locations. (6) Remove the 9 head bolts from each cylinder head
and remove cylinder heads (Fig. 7).
Fig. 5 Rocker Arm Location Left Blank
Fig. 6 Cylinder Head Assembly
Fig. 7 Cylinder Head Bolts Location
9 - 102 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

(2) Clean varnish deposits from inside of tappet
body above plunger cap. (3) Invert tappet body and remove plunger cap,
plunger, flat or ball check valve, check valve spring,
check valve retainer and plunger spring. Check valve
could be flat or ball.
CLEANING AND ASSEMBLY
(1) Clean all tappet parts in a solvent that will re-
move all varnish and carbon. (2) Replace tappets that are unfit for further ser-
vice with new assemblies. (3) If plunger shows signs of scoring or wear, valve
is pitted, or valve seat on end of plunger indicates
any condition that would prevent valve from seating,
install a new tappet assembly. (4) Assemble tappets (Fig. 27).
INSTALLATION
(1) Lubricate tappets.
(2) Install tappets in their original positions.
(3) With roller tappets, install aligning yokes with
(Fig. 26). (4) Install yoke retainer and torque screws to 12
N Im (105 in. lbs.) (Fig. 26).
(5) Install cylinder heads. Refer to cylinder head
installation of this section for procedure. (6) Start and operate engine. Warm up to normal
operating temperature.
CAUTION: To prevent damage to valve mechanism,
engine must not be run above fast idle until all hy-
draulic tappets have filled with oil and have become
quiet.
VALVE TIMING
(1) Remove front valve cover and all 6 spark plugs.
(2) Rotate engine until the #2 piston is at TDC of
the compression stroke. (3) Install a degree wheel on the crankshaft pulley.
(4) With proper adaptor, install a dial into #2
spark plug hole. Using the indicator find TDC on the
compression stroke. (5) Position the degree wheel to zero.
(6) Remove dial indicator from spark plug hole. (7) Place a 5.08mm (.200 inch) spacer between the
valve stem tip of #2 intake valve and rocker arm
pad. Allow tappet to bleed down to give a solid tap-
pet effect. (8) Install a dial indicator so plunger contacts the
#2 intake valve spring retainer as nearly perpendic-
ular as possible. Zero the indicator. (9) Rotate the engine clockwise until the in take
valve has lifted .254mm (0.010 inch).
CAUTION: Do not turn crankshaft any further clock-
wise as intake valve might bottom and result in se-
rious damage.
(10) Degree wheel should read 3 degrees BTDC to
4 degrees ATDC.
TIMING CHAIN COVER, OIL SEAL AND CHAIN
COVER
REMOVAL
(1) Disconnect battery.
(2) Drain cooling system. Refer to Cooling System
Group 7 for procedure. (3) Support engine and remove right engine
mount. (4) Raise vehicle on hoist. Drain engine oil.
(5) Remove oil pan and oil pump pick-up. It may
necessary to remove transmission inspection cover. (6) Remove right wheel and inner splash shield.
(7) Remove drive belt. Refer to Cooling System
Group 7 for procedure. (8) Remove A/C compressor and set aside.
(9) Remove A/C compressor mounting bracket.
(10) Remove crankshaft pulley (Fig. 1).
(11) Remove idler pulley from engine bracket.
(12) Remove engine bracket (Fig. 2).
(13) Remove cam sensor from chain case cover
(Fig. 3).
Fig. 27 Hydraulic Roller Tappet Assembly
Fig. 1 Removing Crankshaft Pulley
Ä 3.3/3.8L ENGINE 9 - 109

(14) Remove chain case cover (Fig. 3).
MEASURING TIMING CHAIN FOR STRETCH
(1) Place a scale next to timing chain so that any
movement of chain may be measured. (2) Place a torque wrench and socket on camshaft
sprocket attaching bolt and apply torque in direction of
crankshaft rotation to take up slack; 41 N Im (30 ft. lb.)
with cylinder head installed or 20 N Im (15 ft. lb.) with
cylinder heads removed. With a torque applied to
the camshaft sprocket bolt, crankshaft should
not be permitted to move. It may be necessary to
block crankshaft to prevent rotation. (3) Holding a scale even, with dimension reading as
shown (Fig. 4 ), along edge of chain links. Apply torque
in the reverse direction to 41 N Im (30 ft. lbs.) with
cylinder heads installed, or 20 N Im (15 ft. lbs.) with
cylinder heads removed. Check amount of chain move-
ment (Fig. 4). (4) Install a new timing chain, if its movement
exceeds 3.175mm (1/8 inch) (Fig. 4). (5) If chain is not satisfactory, remove camshaft
sprocket attaching bolt, and remove timing chain with
camshaft sprocket. (6) Using a suitable puller remove the crankshaft
sprocket. Be careful not to damage the crankshaft
surface. (7) Position a new crankshaft sprocket on the shaft,
install sprocket with suitable tool and mallet. Be sure
sprocket is seated into position. (8) Rotate crankshaft so the timing arrow is to the
12 O'clock position. (9) Place timing chain around camshaft sprocket
and place the timing mark to the 6 O'clock position. (10) Align the dark colored links with the dot on the
camshaft sprocket, place timing chain around crank-
shaft sprocket with the dark colored link lined up with
the dot on the sprocket and install camshaft sprocket
into position. (11) Using straight edge to check alignment of tim-
ing marks (Fig. 5). (12) Install camshaft bolt and washer. Tighten to 54
N Im (40 ft. lbs.).
(13) Rotate crankshaft 2 revolutions. Timing marks
should line up. If timing marks do not line up remove
cam sprocket and realign. (14) Check camshaft endplay. With new thrust plate
specification is .0127 to .304 mm (.005 to .012 inches.).
Old thrust plate specification is .31 mm (.012 inch.)
maximum. If not within these limits install new thrust
plate. (15) Install timing chain snubber. Tighten retaining
screws to 12 N Im (105 in. lbs.). These bolts are
20mm long for this model year, they should not
be interchanged with previous year engines .
INSTALLATION (1) Be sure mating surfaces of chain case cover and
cylinder block are clean and free from burrs. Crank-
shaft oil seal must be removed to insure correct oil
pump engagement. (2) Use a new cover gasket, O-rings. (Fig. 6).
Fig. 3 Timing Chain Case Cover
Fig. 4 Measuring Timing Chain Wear and Stretch
Fig. 2 Engine Bracket
9 - 110 3.3/3.8L ENGINE Ä

(3) Rotate crankshaft so that the oil pump drive
flats are vertical. (4) Position oil pump inner rotor so the mating
flats are in the same position as the crankshaft drive
flats (Fig. 6). (5) Install cover onto crankshaft. Make sure the oil
pump is engaged on the crankshaft correctly or se-
vere damage may result. (6) Install chain case cover screws and torque to 27
N Im (20 ft. lbs.).
(7) Install crankshaft oil seal (Fig. 7).
(8) Install crankshaft pulley (Fig. 8).
(9) Install engine bracket (Fig. 2) torque screws to
54 N Im (40 ft. lbs.).
(10) Install idler pulley on engine bracket. (11) Install cam sensor Refer to Ignition System
Group 8D for installation procedure. (12) Install A/C compressor mounting bracket.
(13) Install A/C compressor.
(14) Install drive belt Refer to Cooling System
Group 7 for installation procedure. (15) Install inner splash shield and wheel.
(16) Install oil pump pick-up and oil pan and
transmission inspection cover if removed. (17) Install engine mount.
(18) Fill crankcase with oil to proper level.
(19) Fill cooling system Refer to Cooling System
Group 7 for procedure. (20) Connect battery.
TIMING CHAIN COVER EXTERNAL OIL SEAL
REMOVAL
(1) Raise vehicle on hoist. Remove right wheel and
inner splash shield. (2) Remove drive belt. (Refer to Cooling System
Group 7) for procedure. (3) Remove crankshaft pulley (Fig. 1).
Fig. 5 Alignment of Timing Marks
Fig. 6 Timing Chain Case Cover Gaskets and O-Rings
Fig. 7 Install Crankshaft Oil Seal
Fig. 8 Installing Crankshaft Pulley
Ä 3.3/3.8L ENGINE 9 - 111

(4) Using Tool C-4991 to remove oil seal (Fig. 9).
Be careful not to damage that crankshaft seal sur-
face of cover.
INSTALLATION (1) Install new seal by using Tool C-4992 (Fig. 7).
(2) Place seal into opening with seal spring to-
wards the inside of engine. Install seal until flush
with cover. (3) Install crankshaft pulley using plate L-4524.
Thrust Bearing/washer and 5.9 inch screw (Fig. 8). (4) Install drive belt (Refer to Cooling System
Group 7) for installation procedure. (5) Install inner splash shield and wheel.
CAMSHAFT
REMOVALÐENGINE REMOVED FROM VEHICLE
Remove intake manifold, cylinder head covers, cyl-
inder heads, timing chain case cover and timing
chain. (1) Remove rocker arm and shaft assemblies.
(2) Remove push rods and tappets; identify so each
part will be replaced in its original location. (3) Remove camshaft thrust plate (Fig. 10).
(4) Install a long bolt into front of camshaft to fa-
cilitate removal of the camshaft; remove camshaft,
being careful not to damage cam bearing with the
cam lobes.
INSTALLATION
(1) Lubricate camshaft lobes and camshaft bearing
journals and insert the camshaft to within 2 inches
of its final position in cylinder block. Whenever an engine has been rebuilt or a new
camshaft or tappets have been installed, add one
pint of Chrysler Crankcase Conditioner or
equivalent to engine oil to aid in break in. The oil
mixture should be left in engine for a minimum
of 805km (500 miles) and drained at the next
normal oil change. (2) Install camshaft thrust plate with two screws as
shown in (Fig. 10). Tighten to 12 N Im (105 in. lbs.)
torque. (3) Rotate crankshaft so the timing arrow is to the
12 O'clock position. (4) Place timing chain around camshaft sprocket
and place the timing mark to the 6 O'clock position. (5) Align the dark colored links with the dot on the
camshaft sprocket, place timing chain around crank-
shaft sprocket with the dark colored link lined up with
the dot on the sprocket and install camshaft sprocket
into position. (6) Using straight edge to check alignment of timing
marks (Fig. 5). (7) Install the camshaft bolt. Tighten bolt to 54 N Im
(40 ft. lbs.). (8) Rotate crankshaft 2 revolutions. Timing marks
should line up. If timing marks do not line up, remove
cam sprocket and realign.
Fig. 9 Removing Crankshaft Oil Seal
Fig. 10 Camshaft Thrust Plate
Fig. 11 Camshaft and Sprocket Assembly
9 - 112 3.3/3.8L ENGINE Ä