check engine CHEVROLET DYNASTY 1993 Owners Manual

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

(2) Inspect each valve spring for squareness with a
steel square and surface plate, test springs from both
ends. If the spring is more than 1.5mm (1/16 inch)
out of square, install a new spring.
REFACING VALVES AND VALVE SEATS (1) The intake and exhaust valve seats and valve
face have a 45 degree angle.
(2) Inspect the remaining margin after the valves are
refaced (Fig. 23). Exhaust valves with less than
1.191mm (3/64 inch) margin and intake valves with less
than .794mm (1/32 inch) margin should be discarded. (3) When refacing valve seats, it is important that
the correct size valve guide pilot be used for reseating
stones. A true and complete surface must be obtained.
(4) Measure the concentricity of valve seat using a
valve seat dial indicator. Total runout should not ex-
ceed. 051mm (.002 inch) (total indicator reading).
(5) Inspect the valve seat with Prussian blue to deter-
mine where the valve contacts the seat. To do this, coat
valve seat LIGHTLY with Prussian blue then set valve
in place. Rotate the valve with light pressure. If the
blue is transferred to the center of valve face, contact is
satisfactory. If the blue is transferred to top edge of the
valve face, lower valve seat with a 15 degrees stone. If
the blue is transferred to the bottom edge of valve face
raise valve seat with a 65 degrees stone.
² Intake valve seat diameter 40.45mm (1.593 inch)
² Exhaust valve seat diameter 34.84mm (1.371 inch)
Valve seats which are worn or burned can be re-
worked, provided that correct angle and seat width are
maintained. Otherwise cylinder head must be replaced.
(6) When seat is properly positioned the width of
intake seats should be 1.75 to 2.25mm (0.69 to .088
inch) The width of the exhaust seats should be 1.50
to 2.00mm (.059 to .078 inch) (Fig. 24 Dimension 1).
(7) Check valve tip to spring seat dimensions after
grinding the valve seats or faces. Grind valve tip to get
49.76 to 51.04mm (1.960 to 2.009 inch) over spring seat
when installed in the head (Fig. 25). The valve tip di-
ameter should be no less than 7.0mm (0.275 inch), if
necessary, the tip chamfer should be reground to pre-
vent seal damage when the valve is installed.
Fig. 21 Intake and Exhaust Valves
Fig. 22 Valve Dimensions
Fig. 23 Refacing Intake and Exhaust Valves
Fig. 24 Refacing Valve Seats
Ä 2.2/2.5L ENGINE 9 - 29

(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

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

(2) Install thrust plates and tighten retaining nuts
to6N Im (55 in. lbs.).
(3) Install new camshaft oil seals flush with cylin-
der head surface. Using seal installing special tool C-4680.
CAMSHAFT END PLAY
(1) Using a suitable tool, move camshaft as far
rearward as it will go. (2) Zero dial indicator (Fig. 6).
(3) Move as far forward and backward as camshaft
will go. (4) End play travel: 0.025-0.200mm (.001-.008
inch).
LASH ADJUSTER (TAPPET) NOISE
A tappet-like noise may be produced from several
items. See Lash Adjuster and Tappet Noise-DIAG-
NOSIS in STANDARD SERVICE PROCEDURES,
this Group.
VALVE COMPONENTS REPLACEÐCYLINDER HEAD
NOT REMOVED
ROCKER ARM AND HYDRAULIC LASH
ADJUSTER
REMOVAL
(1) Remove valve cover. Refer to procedure previ-
ously outlined in this section.
(2) Remove rocker arm shaft(s) in sequence shown
in (Fig. 6). Slide rocker off the shaft. Keep rocker
arms in order for reassembly.
CAUTION: Check lash adjusters for loose or miss-
ing retainers before continuing service procedure.
(3) Remove hydraulic lash adjuster.
Fig. 5 Measuring Camshaft Lobe Wear
Fig. 6 Checking Camshaft End Play
Fig. 7 Rocker Arm ShaftÐRemoval
Fig. 8 Rocker Arm and Lash Adjuster AssemblyÐRight and Left
Ä 2.2/2.5L ENGINE 9 - 37

REFACING VALVES AND VALVE SEATS
(1) The intake and exhaust valve seats and valve
face have a 45 degree angle. (2) Inspect the remaining margin after the valves
are refaced (Fig. 11). Exhaust valves with less than
1.07mm (3/64 inch) margin and intake valves with
less than 1.06mm (3/64 inch) margin should be dis-
carded. (3) When refacing valve seats, it is important that
the correct size valve guide pilot be used for reseat-
ing stones. A true and complete surface must be ob-
tained. (4) Measure the concentricity of valve seat using a
valve seat dial indicator. Total runout should not ex-
ceed. 0.1 mm (.004 inch) (total indicator reading). (5) Inspect the valve seat with Prussian blue to de-
termine where the valve contacts the seat. To do
this,coat valve seat LIGHTLYwith Prussian blue
then set valve in place. Rotate the valve with light
pressure. If the blue is transferred to the center of
valve face, contact is satisfactory. If the blue is trans-
ferred to top edge of the valve face, lower valve seat
with a 15 degrees stone. If the blue is transferred to
the bottom edge of valve face raise valve seat with a
65 degrees stone.
² Intake valve seat diameter 34.0mm (1.338 inch)
² Exhaust valve seat diameter 29.4mm (1.157 inch) Valve seats which are worn or burned can be re-
worked, provided that correct angle and seat width
are maintained. Otherwise cylinder head must be re-
placed. (6) When seat is properly positioned the width of
intake seats should be 1.87mm (0.73 inch) The width
of the exhaust seats should be 2.00mm (.078 inch)
(Fig. 16 Dimension 1). (7) Check valve tip to spring seat dimensions A af-
ter grinding the valve seats or faces. Grind valve tip
to give 55.62 to 55.88 mm (2.190 to 2.200 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. (8) Check the valve spring installed height B after
refacing the valve and seat (Fig. 17). Measurement B
is to be taken from the spring seat to the bottom of
the spring retainer. Correct height is 44.0mm (1.73
inches).
Fig. 13 Measuring Valve Guides
Fig. 14 Valve Dimensions
Fig. 15 Refacing Intake and Exhaust Valves
Fig. 16 Refacing Valve Seats
Ä 2.2/2.5L ENGINE 9 - 39

VALVE GEAR REASSEMBLY AFTER VALVE SERVICE
(1) Coat valve stems with lubrication oil and insert
in cylinder head. (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. (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 Valve Spring Compressor Tool C-3422-B
with adopters 6537 and 6526 (Fig. 11) the locks can
become dislocated. Check to make sure both locks
are in their correct location after removing tool.
(4) Check installed height of springs. Measurement
B is to be taken from the spring seat to the bottom of
the spring retainer. Correct height is 44.0mm (1.73
inches). If seats have been ground an additional
spring seat may be required to maintain correct in-
stalled spring height (Fig. 17). (5) Install camshaft and rocker arms as previously
described, see Camshaft-Install.
Fig. 17 Checking Valve Tip Height and Spring Installed Height
9 - 40 2.2/2.5L ENGINE Ä