1993 CHEVROLET DYNASTY oil

valve spring retainer locks to become dislocated
when depressing the valve spring. Check and make
sure the locks are in their proper location. (3) Install valve cover as previously outlined in
this section.
VALVE SPRINGS AND VALVE STEM SEALS
REMOVAL
(1) Remove rocker arms as previously outlined in
this section. (2) Rotate crankshaft until piston is at TDC on
compression. (3) With air hose attached to adapter tool installed
in spark plug hole, apply 90-120 psi air pressure. (4) Using Special Tool C-4682 (Fig. 12) compress
valve springs and remove valve locks. (5) Remove valve spring.
(6) Remove valve stem seal by gently prying side-
to-side with a screwdriver blade. Once dislodged from
guide post, seal may be easily removed.
INSTALLATION
CAUTION: Flexible Fuel Vehicle Valve use unique
valve stem oil seals they are green in color. Stan-
dard valve stem oil seals are NOT to be interchanged
with Flexible Fuel Vehicles engines.
(1) Install valve seals (Fig. 13) as outlined in step
(2) of Valve Gear Reassembly - After Valve Ser-
vice in this section.
(2) Using Special Tool C-4682 compress valve
springs only enough to install locks. Correct align-
ment of tool is necessary to avoid nicking valve
stems (air pressure required), piston at TDC. (3) Install rocker arms as previously outlined in
this section.
CYLINDER HEAD
REMOVAL
(1) Perform fuel system pressure release procedure
before attempting any repairs. Refer to Fuel Sys-
tem Group 14 (2) Disconnect negative battery cable. Drain cool-
ing system. Refer to Cooling System, Group 7. (3) Remove air cleaner and disconnect all vacuum
lines, electrical wiring and fuel lines from throttle
body. (4) Remove throttle linkage.
(5) Loosen power steering pump and remove belt.
(6) Remove power brake vacuum hose from intake
manifold. (7) Remove water hoses from water crossover.
(8) Raise vehicle and remove exhaust pipe from
manifold. (9) Remove power steering pump assembly and set
aside. (10) Disconnect coil wiring connector and coil wire
from coil. (11) Disconnect dipstick tube from thermostat
housing and ROTATEbracket from stud. DO NOT
bend the bracket or tube. (12) See Solid Mount Compressor Bracket in
STANDARD SERVICE PROCEDURES, this Group. (13) Remove cylinder head bolts.
INSPECT HEAD AND CAMSHAFT BEARINGJOURNALS
(1) Cylinder head must be flat within 0.1mm (.004
inch) (Fig. 14). (2) Inspect camshaft journals for scoring and jour-
nal caps for oversize markings. When servicing cyl-
inder head or camshaft, it is necessary to be certain
that oversized camshafts are used only in oversized
heads. Identify oversize components as follows:
Fig. 12 Removing and Installing Valve SpringFig. 13 Valve Stem Seals
9 - 26 2.2/2.5L ENGINE Ä

Cylinder Head: Top of bearing caps painted green
and O/SJ stamped rearward of oil gallery plug on end
of head. Camshaft: Barrel of camshaft painted greenand
O/SJ stamped on end of shaft.
CLEANING
Remove all gasket material from cylinder head and
block. Be careful not gouge or scratch the aluminum
head sealing surface.
INSTALLATION
CAUTION: Head bolt diameter is 11mm. These bolts
are identified with 11 on the head of the bolt. 10mm
bolts will thread into the 11mm hole but will strip the
cylinder block bolt hole .
Since the Cylinder head bolts are torqued us-
ing a new procedure they should be examined
BEFORE reuse. If the threads are necked down
the bolts should be replaced (Fig. 16) .
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. (1) Before installing the bolts the threads should be
oiled with engine oil. (2) Install both bolts in each cap finger tight, then
alternately torque each bolt to assemble the cap prop-
erly. (3) Tighten the cylinder head bolts in the sequence
shown in (Fig. 17). 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. Bolt torque after 1/4 turn should be over 90 ft. lbs. If
not, replace the bolt. (4) Rotate dipstick tube or bracket onto stud.
Tighten bracket retaining nut to 23 N Im (200 in.
lbs.)
VALVE SERVICEÐCYLINDER HEAD REMOVED
VALVES AND VALVE SPRINGS
REMOVAL
(1) With cylinder head removed, compress valve
Fig. 15 Cylinder Head Gaskets
Fig. 16 Checking Bolts for Stretching (Necking)
Fig. 17 Cylinder Head Tightening Sequence
Fig. 14 Checking Cylinder Head Flatness
Ä 2.2/2.5L ENGINE 9 - 27

(8) Check the valve spring installed height after
refacing the valve and seat (Fig. 26).
CAUTION: If more than .5mm (.020 inch) must be
ground from the valve tip, check the clearance be-
tween the rocker arm and the valve spring retainer
if below 1.25mm (.050 inch), grind the rocker arm
ears according to the procedure described in Refac-
ing Valves and Valve Seats.
CLEANING
Clean all valve guides, valves and valve spring as-
semblies thoroughly with suitable cleaning solution
before reassembling.
VALVE GEAR REASSEMBLY AFTER VALVE SERVICE (1) Coat valve stems with lubrication oil and insert
in cylinder head. CAUTION: Flexible Fuel Vehicles use unique valve
stem oil seals they are green in color. Standard
valve stem oil seals are NOT to be interchanged with
Flexible Fuel Vehicles engines.
(2) Install new valve stem seals on all valves. The
valve stem seals should be pushed firmly and
squarely over valve guide. The lower edge of the seal
should be resting on the valve guide boss.
CAUTION: When oversize valves are used, the cor-
responding oversize valve seal must also be used.
Excessive guide wear may result if oversize seals
are not used with oversize valves.
(3) Install valve spring seats and springs and re-
tainers. Compress valve springs only enough to in-
stall locks, taking care not to misalign the direction
of compression. Nicked valve stems may result from
misalignment of the valve spring compressor.
CAUTION: When depressing the valve spring retain-
ers with Tool C-3422-B the locks can become dislo-
cated. Check to make sure both locks are in their
correct location after removing tool .
(4) Check installed height of springs. Measurement
is to be taken from the spring seat to the bottom of
the spring retainer. Correct height is 41.2mm to
42.7mm (1.62 to 1.68 inches). If seats have been re-
ground an additional spring seat may be required to
maintain correct installed spring height. (5) Install adjusters, rocker arms in order, and
camshaft as previously described, see Camshaft-In-
stall. Check for clearance between the projecting ears
(either side of valve tip) of the rocker arms and the
valve spring retainers. At least 1.25 mm (.050 inch)
clearance must be present, if necessary, the rocker
arm ears may be ground to obtain this clearance
(Fig. 26). (6) Checking dry lash. Dry lash is the amount of
clearance that exists between the base circle of an in-
stalled cam and the rocker arm roller when the ad-
juster is drained of oil and completely collapsed.
Specified dry lash is 0.62 to 1.52 mm (.024 to .060
inch). To completely collapse adjuster for dry lash
measurement, pry off retainer cap, disassemble,
drain the adjuster of oil, reassemble, and install. Af-
ter performing dry lash check, refill adjuster with oil
(do not reuse retainer cap/s) and allow 10 minutes for
adjuster/s to bleed down before rotating cam.
Fig. 25 Valve Tip to Spring Seat Dimensions
Fig. 26 Checking Spring Installed Height and Spring Retainer Clearance
9 - 30 2.2/2.5L ENGINE Ä

CYLINDER HEAD AND VALVE ASSEMBLY
SERVICEÐTURBO III
CYLINDER HEAD COVER SEALING
(1) Before installation, clean cylinder head and cover
mating surfaces. Make certain rails are flat.
Caution: Do not allow oil or solvents to contact the
timing belt as they can deteriorate the rubber and
cause tooth skipping.
(2) Install covers and gasket assembly to head and
torque to 12 N Im (105 in.lbs.).
CYLINDER HEAD
REMOVAL
Refer to Intake and Exhaust Manifold Service in
Exhaust Systems and Intake Manifold Group 11 for
removal procedure for the intake and exhaust mani-
folds. (1) The Timing Belt and Solid Mount Compressor
Mount Bracket must be removed before the cylinder
head can be removed. Refer to procedure outlined in
this group for service procedures. (2) Remove cylinder head bolts.
(3) Cylinder head must be flat within 0.1mm (.004
inch) (Fig. 2).
INSTALLATION
CAUTION: The Turbo III head gasket is not the same
as any other engine head gasket (Fig. 3).
CAUTION: Head bolt diameter is 11mm. These bolts
are Unique to this engine application they are not
interchangeable with other engines.
The Cylinder head bolts are torqued using a
new procedure they should be examined BE-
FORE reuse. If the threads are necked down the
bolts should be replaced. (Fig. 4 ). 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.
Fig. 2 Checking Cylinder Head Flatness
Fig. 3 Cylinder Head Gaskets
Fig. 4 Checking Bolts for StretchingÐNecking
Fig. 1 Cylinder Head Valve Cover and Gasket As- sembly
Ä 2.2/2.5L ENGINE 9 - 31

Before installing the bolts, the threads should be
cleaned and oiled. Tighten the cylinder head bolts in the sequence
shown in (Fig. 5 ). 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 torque wrench
for this step.
² Bolt torque after 1/4 turn should be over 90 ft. lbs.
If not, replace the bolt. Refer to Intake and Exhaust Manifold Service in
Exhaust Systems and Intake Manifold Group 11 for
installation procedure. Refer to the Timing Belt and Solid Mount Com-
pressor Mount Bracket service procedures in this
group for installations procedures.
TIMING BELT COVER SERVICEÐTURBO III
ENGINE
REMOVAL
(1) Remove PCV tube and upper timing belt cover
screws (Fig. 1). Remove upper cover. (2) Remove accessory drive belt. Refer to Cooling
System Group 7 for procedure. (3) Raise vehicle on a hoist and remove right
wheel and inner splash shield (Fig. 2).
(4) Remove water pump pulley and crankshaft pul-
ley retaining bolts (Fig. 3), remove pulleys. (5) Remove lower accessory drive belt idler and
tensioner pulley (Fig. 4).
Fig. 1 Timing Belt Cover Screws
Fig. 5 Cylinder Head Tightening Sequence
Fig. 2 Right Inner Splash Shield
Fig. 3 Crankshaft and Water Pump Pulleys
9 - 32 2.2/2.5L ENGINE Ä

CAMSHAFT AND CRANKSHAFT TIMING
PROCEDURE
INSTALLATION
(1) Remove air cleaner fresh air duct.
(2) Remove ignition cable cover (Fig. 7).
(3) Remove valve covers and loosen rocker arm as-
semblies about 3 turns as shown in (Fig. 8).
CAUTION: Check lash adjuster for loose or missing
retainers before continuing service procedure.
(4) Align and pin both intake and exhaust cam
sprockets with 3/32 drills or pin punches (Fig. 9). Ac-
cessory Shaft does not need to be timed. (5) Remove spark plugs.
(6) Install a dial indicator in Number 1 spark plug
hole (Fig. 10). (7) Rotate crankshaft till number 1 piston is at
Top Dead Center. Mark the engine block for TDC
reference. (8) Install timing belt and idler pulley in sequence
shown in (Fig. 11). (9) Remove dial indicator from cylinder head (Fig.
10). Remove drills or pins from camshaft sprockets
(Fig. 11). (10) Adjust tension to 445 N (110 lbs.)
New beltor
311 N (70 lbs.) Used belt. Install belt tension gauge on
timing belt (Fig. 12) adjust tensioner until specified
tension is achieved.
CAUTION: Belt tension gauge must be installed be-
tween the belt teeth to get a accurate reading .
(11) Rotate crankshaft clockwise 2 full revolutions
and check alignment of camshaft and crankshaft tim-
ing marks. Do not reverse rotate crankshaft or
attempt to rotate engine using cam or accessory
shaft attaching screw.
CAUTION: Do not allow oil or solvents to contact the
timing belt as they can deteriorate the rubber and
cause tooth skipping.
Fig. 7 Ignition Cable Cover
Fig. 8 Rocker Arm Shaft Assemblies
Fig. 9 Camshafts Pinned Into Position
Fig. 10 Dial Indicator Located in Number 1 Cylinder
9 - 34 2.2/2.5L ENGINE Ä

(12) Recheck belt tension, adjust if necessary.
(13) Torque rocker arm shafts in sequence shown
(Fig. 13) to 12 N Im (105 in. lbs.) then to 24 N Im (210
in. lbs.). (14) Install valve covers, spark plugs, ignition cables
and ignition cable cover. (15) Install air cleaner fresh air duct.
(16) Raise vehicle. Install lower timing belt cover
and accessory drive belt tensioner pulley. Refer to
procedure in this section. (17) Lower vehicle. Install right engine mount (Fig.
5). (18) Inspect foam stuffer block condition and posi-
tion (Fig. 14). Stuffer block should be intact and secure
within the engine bracket tunnel. (19) Install upper timing belt cover and PCV tube.
Refer to procedure in this section. (20) Install accessory drive belt. Refer to procedure
in this section.
SERVICING OIL SEALS
Refer to servicing oil seals in this group for proce-
dures. To service the intake cam seal (Turbo III) the
right engine mount must be removed. Refer to
engine mount removal of this Group.
Fig. 13 Rocker Arm ShaftÐInstallation
Fig. 14 Foam Stuffer Block Location
Fig. 11 Camshafts and Crankshaft Timing Marks
Fig. 12 Belt Tension Gauge Location
Ä 2.2/2.5L ENGINE 9 - 35

CAMSHAFTS SERVICE
Cylinder Head must be removed from vehicle. Re-
fer to cylinder head removal for procedure.
REMOVAL
(1) Mark rocker arms shafts for reinstallation in
the same position (Fig. 1). (2) Remove rocker arm assembly attaching bolts in
sequence (Fig. 1 ). (3) Remove thrust plates from rear of camshafts
(Fig. 2).The intake camshaft uses a wider thrust
plate than exhaust camshaft.
CAUTION: Thrust plates are not the same thickness
and cannot be interchanged.
(4) Before camshaft can be removed from cylinder
head the cam seal must be removed first. Becareful
not to damage seal surface of the camshaft. (5) Using a screwdriver place it against the side of
the cam lobe push the cam out of the head. The cam
seal will be pushed out by the cam (Fig. 3). (6) Slide the camshaft out of the cylinder head. Be-
careful not scratch the bearing surfaces in the head
(Fig. 4).
CAUTION: Intake and Exhaust camshafts are not in-
terchangeable .
INSPECTION
Camshaft lobe wear should not exceed .25mm (.010
inch). To measure cam lobe wear (Fig. 4), measure
lobe diameter in two places at the largest diameter
(over the nose). Take first reading with micrometer
in unworn area at the edge of the lobe. Take second
reading in the worn area where rocker arm contacts
the lobe. Subtract second reading from the first. The
difference is the cam lobe wear.
INSTALLATION
(1) Lubricate camshaft journals with clean engine
oil. Carefully install camshaft into the head.
CAUTION: Camshafts are not interchangeable. The
intake cam has a wider thrust plate groove.
Fig. 3 Removing Camshaft Oil Seal
Fig. 1 Rocker Arm Shaft Removal Sequence
Fig. 2 Camshaft Thrust Plates
Fig. 4 CamshaftÐRemoval or Installation
9 - 36 2.2/2.5L ENGINE Ä