service CHEVROLET DYNASTY 1993 Service Manual

CYLINDER HEAD AND VALVE ASSEMBLY SERVICEÐEXCEPT TURBO III
Fig. 1 Cylinder Head and Valve Assembly Service
9 - 22 2.2/2.5L ENGINE Ä

CYLINDER HEAD COVER AND CURTAIN
A curtain aiding air/oil separation is installed on
the cylinder head below the cylinder head cover
(Figs. 1 and 2).
REMOVAL
(1) Remove the cylinder head cover bolts (Fig. 2).
(2) Remove cylinder head cover and curtain from
cylinder head. Do not misplace the rubber bumpers
on curtain.
CLEANING
Before installation, clean cylinder head and cover
mating surfaces. Make certain the rails are flat.
CURTAIN INSTALLATION
Install curtain manifold side first with cutouts over
cam towers and contacting cylinder head floor, then
press opposite distributor side into position below cyl-
inder head rail. Curtain is retained in position with rubber
bumpers (Fig. 1).
COVER SEALING AND INSTALLATION
Before installation, clean cylinder head and cover
mating surfaces. Make certain rails are flat. (1) Install new end seals on valve cover.
(2) Apply form-in-place Mopar Silicone Rubber Ad-
hesive Sealant or equivalent gasket material to cyl-
inder head cover rail (Fig. 3). Refer to procedure
detailed in form-in-place gasket section of Standard
Service Procedures, in this Group.
Caution: Do not allow oil or solvents to contact the
timing belt as they can deteriorate the rubber and
cause tooth skipping.
(3) Install curtain, cover and end seal assembly to
head and tighten to 12 N Im (105 in.lbs.) torque.
CYLINDER HEAD COMPONENTSÐIN-VEHICLE
SERVICE
Removal and installation of cylinder head or cam-
shaft require separation of camshaft timing sprocket
from camshaft. To maintain camshaft, intermediate
shaft, and crankshaft timing during service proce-
dures, the timing belt is left indexed on the sprocket
while the assembly is suspended under light tension
(Fig. 4). When removing the sprocket from the camshaft,
you must maintain adequate tension on the sprocket
and belt assembly to prevent the belt from disengag-
ing with the intermediate or crankshaft timing
sprockets. Refer to Timing System and Seals for re-Fig. 2 Cylinder Head Cover and Curtain
Fig. 3 Cylinder Head Valve Cover Rail SealingFig. 4 Suspending Camshaft Sprocket
Ä 2.2/2.5L ENGINE 9 - 23

moval and installation of camshaft sprocket proce-
dure and to Camshaft Service for removal and
installation of camshaft procedures.
CAUTION: Failure to maintain adequate tension on
camshaft, intermediate, and crankshaft sprocket
belt can result in lost engine timing. If timing is
lost, refer to Timing System and Seals and (Fig. 4).
CAMSHAFT SERVICE
Refer to TIMING SYSTEM AND SEALS for cam- shaft timing belt and sprocket removal and installa-
tion, and CYLINDER HEAD In Vehicle Service.
REMOVAL
(1) Remove the cylinder head cover and curtain.
(2) Mark rocker arms for reinstallation in the
same position (Fig. 6). (3) Loosen camshaft bearing cap screws several
revolutions (Fig. 7). (4) Jar camshaft at rear of cam to loosen (break
free) the bearing caps. Use a soft faced mallet.
CAUTION: Care should be exercised not to cock the
camshaft during removal. Cocking of the camshaft
could cause damage to the cam or bearing thrust
surfaces.
(5) Remove screws and caps such that cam does
not cock.
INSPECTION
Check bearing cap and oil feed holes for blockage.
Inspect bearing cap and cylinder head journals for
wear and/or oversize, Refer to CYLINDER HEAD,
Inspect and Specifications.
Fig. 5 Engine Sprocket Timing
Fig. 6 Rocker Arm and Lash Adjuster
Fig. 7 Camshaft Cap Removal Sequence
Fig. 8 Camshaft
9 - 24 2.2/2.5L ENGINE Ä

Camshaft bearing journals and lobe wear. Lobe
wear should not exceed .25mm (.010 inch). To mea-
sure cam lobe wear (Fig. 8), 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. Sub-
tract second reading from the first. The difference is
the cam lobe wear.
CAMSHAFT END PLAY
(1) Oil camshaft journals and install camshaft
without cam followers. Tighten screws to specified
torque. (2) Using a suitable tool, move camshaft as far
rearward as it will go. (3) Zero dial indicator (Fig. 9).
(4) Move camshaft as far forward as it will go.
(5) End play travel: 0.13 - 0.33mm (0.005 - 0.013
inch.). (6) Remove bearing caps and camshaft.
INSTALLATION
(1) Install cam followers in correct order as re-
moved. (2) Align camshaft bearing caps in proper sequence
with Cap No. 1 at timing belt end and Cap No. 5 at
transmission end. Arrows on Caps No. 1, 2, 3, 4
must point toward timing belt to prevent cap break-
age (Fig. 11). (3) Apply Mopar Gasket Maker to No.1 and No.5
bearing cap (Fig. 10). (4) Caps must be installed before camshaft seals
are installed.
LASH ADJUSTER (TAPPET) NOISE
A tappet-like noise may be produced from several
items. Refer to Lash Adjuster and Tappet Noise - Di-
agnosis in Standard Service Procedures, this Group.
VALVE COMPONENTS REPLACEÐCYLINDER HEAD NOT REMOVED
ROCKER ARM AND HYDRAULIC LASH ADJUSTER
REMOVAL
(1) Remove valve cover.
(2) For each rocker arm, rotate cam until base cir-
cle is in contact with rocker arm. Depress valve
spring using Special Tool C-4682 (Fig. 12) and slide
rocker arm out. Keep rocker arms in order for reas-
sembly. (3) Remove hydraulic lash adjuster.
INSTALLATION
(1) Install hydraulic lash adjusters making sure
that adjusters are at least partially full of oil. This is
indicated by little or no plunger travel when the lash
adjuster is depressed. (2) Rotate cam until base circle is in contact posi-
tion with rocker arm. Depress valve spring with Spe-
cial Tool C-4682 (Fig. 12) and slide rocker arm in
place. Keep rockers in order. It is possible for the
Fig. 9 Camshaft End Play
Fig. 10 Cam Tower Cap Sealing
Fig. 11 Camshaft Bearing Caps Installation
Ä 2.2/2.5L ENGINE 9 - 25

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

springs using Tool C-3422-B. (2) Remove valve retaining locks, valve spring re-
tainers, valve stem seals and valve springs. (3) Before removing valves, remove any burrs
from valve stem lock grooves to prevent damage
to the valve guides. Identify valves to insure instal-
lation in original location.
VALVE INSPECTION (1) Clean valves thoroughly and discard burned,
warped and cracked valves. (2) Measure valve stems for wear.
(3) If valve stems are worn more than 0.05 mm (.002
inch.) replace valve.
VALVE GUIDES
(1) Remove carbon and varnish deposits from inside
of valve guides with a reliable guide cleaner. (2) Checking Valve Guide Wear:
² Insert valve with valve head positioned 10 mm (.400
inch) above cylinder head gasket surface.
²
Move valve to and from the indicator (Fig. 17). The
total dial indicator reading should not exceed the amount
specified in (Fig. 18). Readings should be taken for length-
wise and crosswise (with respect to cylinder head) move-
ment for each valve. Ream the guides for valves with
oversize stems if dial indicator reading is excessive or if
the stems are scuffed or scored.
(3) Service valves with oversize stems and oversize
seals are available in 0.15mm, (.005 inch) 0.40mm,
(.015 inch) and 0.80mm(.031 inch) oversize. Oversize seals must be used with oversize
valves. Reamers sizes to accommodate the oversize valve
stem are shown in (Fig. 18)
(4) Slowly turn reamer by hand and clean guide thor-
oughly before installing new valve. Do not attempt to
ream the valve guides from standard directly to
0.80mm (.030 inch). Use step procedure of 0.15mm
(.005 inch), 0.40mm (.015 inch) and 0.80mm (.030 inch) so the valve guides may be reamed true in
relation to the valve seat. After reaming guides, the
seat runout should be measured and resurfaced if
necessary. Refer to Refacing Valves and Valve Seats.
Replace cylinder head if guide does not clean
up with 0.80 mm (.030 inch) oversize reamer, or if
guide is loose in cylinder head.
TESTING VALVE SPRINGS
(1) Whenever valves have been removed for inspection,
reconditioning or replacement, valve springs should be
tested. As an example, the compression 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 (Fig. 20). 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 mea-
surements are indicated on the table for finer adjust-
ments. Refer to specifications to obtain specified height
and allowable tensions. Discard the springs that do not
meet specifications.
Fig. 18 Checking Wear on Valve GuideÐTypical
Fig. 19 Valve Guide Specification
Fig. 20 Testing Valve Spring with Tool C-647
9 - 28 2.2/2.5L ENGINE Ä

(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