Page 101
Pistons, Connecting Rods, Cylinder Bores
212-5
Table c. Piston Ring Specifications
Top compression ring
Second compression ring
Oil scraper ring
end gap
0.35-0.55 mm
(0.0138-0.0217 in.)
0.30-0.45 mm
(0.0118-0.0177 in.)
0.38-1.40 mm
(0.0150-0.0551 in.)'
width (thickness)
1.73-1.75 mm
(0.0681-0.0689 in.)
1.98-1.99 mm
(0.0780-0.0783 in.)
2.63-2.73 mm
(0.1035-0.1075 in.)"
side clearance in piston groove
0.05-0.09 mm
(0.0020-0.0035 in.)
0.04-0.07 mm
(0.0016-0.0028 in.)
-
•Applies to segment part of ring
"Oil scraper ring segment width (thickness): 0.58-0.64 mm (0.022-0.025 in.)
When installing the rings, install the second compression
ring so that the word "TOP" found on the ring faces up. See
Fig. 7. Make sure the ring end gaps are offset as shown in Fig.
8. Lightly coat the cylinders and the rings with engine oil before installation.
1
1. Compression rings
2. Oil scraper rings
Fig. 8.
Fig. 7.
1
87052 ·S/7871
Position compression ring end gaps 180" apart and directly
above piston pin. Position scraper ring end gaps evenly
around piston and not in line with each other.
"TOP" marking on second compression ring correctly installed.
CYLINDER BLOCK AND PISTON RECONDITIONING
Page 102
Cylinder Head and Valve Mechanism
214-1
214 Cylinder Head and Valve Mechanism
General
214-1
Hydraulic Cam Followers
214-1
Checking and Replacing Hyd raulic
Cam Followers
Bleeding Air Trapped in Cylinder Head
(from Mid-1988 modelsengine no. J082586 and later)
To bleed lubrication system
Valve Mechanism
To remove and install valve cover
To remove and install camshafts
(cylinder head installed)
To replace valve stem oil seals
(cylinder head installed)
To disassemble valve mechanism
(cylinder head removed)
214-7
214-9
214-2
Valve Mechanism Reconditioning
214-3
214-3
214-4
214-4
214-5
Cylinder Head Assembly
Camshafts
Valve Guides
To replace valve guides
Valves and Valve Seats
Scrapping Sodium Filled Valves
To scrap sodium-filled exhaust valves
Valve Springs
214-11
214-11
214-11
214-12
214-12
214-13
214-14
214-14
214-15
GENERAL
Some special tools may be required to disassemble and repair the valve mechanism owing to the cylinder head design.
Read the procedures carefully before starting the job to determine what tools and equipment will be needed.
HYDRAULIC CAM FOLLOWERS
.,
,<\
The valve gear mechanism uses hydraulic cam followers to
keep the valve clearances within a limited working range of
2.055 mm (0.081 in.). See Fig. 1. The cam followers are
sealed units and require no maintenance or adjustment.
Under some circumstances, such as removal and installation of the cylinder head, the cam followers may become
noisy. Hydraulic cam follower noise usually makes a tapping
or chattering sound. In most instances, this is considered normal as long as the noise goes away after a few minutes (maximum of 30 minutes). If the noise does not go away, either the
follower is faulty, the oil pressure to the follower is too low, or
there is trapped air in the system. Some of the common conditions that can cause follower noise are listed below.
1. Starting the engine after an oil change. If the noise was
not present before the oil change, it should go away as
soon as the oil pressure is restored.
....... ',
t<·
'.
:-..
Fig. 1. Cutaway of hydraulic cam follower. Each cam follower consists of two adjacent storage chambers (1), a leakage passage (2), a check valve (3), a high pressure chamber (4), and
a spring (5).
GENERAL
Page 103
214-2
Cylinder Head and Valve Mechanism
2. Starting a cold engine or starting an engine that has
been sitting for long periods. This noise is normal and
should disappear as soon as the oil reaches normal operating pressure.
3. After doing work that required cranking the engine by
hand or by the starter motor. This can cause the oil in
the follower to be forced out. Again, the noise should go
away as soon as the oil pressure is restored. Under severe conditions where the follower has been totally
drained, it may take as long as 30 minutes at engine
speeds between 2,000 and 3,000 rpm to fully expel the
air from the follower.
CAUTION
When trying to restore oil pressure to a hydraulic lifter, do not
raise the engine speed above 3,000 rpm, as cam follower
damage may result.
4. After installing a new replacement cam follower. The oil
in a new follower may drain out if the follower is incorrectly stored. This situation is the same as the drained
follower described above.
5. After a short period of idling (engine hot). Run the engine at 1,500 rpm or above. The noise should disappear. The noise is due to low oil pressure in the
hydraulic cam followers when the engine is idling.
Check the external oil feed pipe connectors and 0rings in the top of the cylinder head, where applicable.
NOTE
On cylinder heads used on mid-1988 and later models, the extemal supply pipes were discontinued owing to a new cylinder
head design. The oil to the followers is now supplied via internal oil passages.
6. Only at high engine speeds. Noise goes away at idle.
This is due to excessive amounts of air in the oil at high
engine speeds. The intake of air into the lubrication
system is most likely caused by a leak on the suction
side of the oil pump. Check the oil pump's suction pipe
O-ring and the suction pipe itself for damage.
HYDRAULIC CAM FOLLOWERS
NOTE
The oil pump suction pipe is in the engine oil sump of the
transmission. To reach the suction pipe, the engine and transmission assembly needs to be removed and the engine separated from the transmission. See 201 Engine Removal and
Installation.
7. Noise at all times, regardless of engine speed or temperature. A noisy follower at all times usually means
that the follower is faulty and should be replaced.
NOTE
On cylinder heads introduced on mid-1988 models, with internal oil passages, it is possible for air to become trapped in the
system, causing cam follower noise. If more than one follower
is exhibiting noise, try bleeding the lubrication system before
checking and/or replacing noisy cam followers as described
below.
Checking and Replacing Hydraulic
Cam Followers
To check for a faulty cam follower, run the engine briefly to
build up oil pressure. Then turn the engine off and remove the
valve cover as described below under Valve Mechanism. Using a wooden stick, press down on the top of the follower. If the
follower feels spongy or can be pressed down at all, it is most
likely faulty and should be replaced. A faulty cam follower can
be easily removed after removing the camshaft as described
below. Use a magnetic tool to remove the cam followers.
NOTE
• Keep in mind that a damaged or poorly sealed oil passageway to the follower may be the cause of the noise rather than
the follower itself.
• Do not mix up cam followers between cylinders. Used cam
followers should always be installed in their original positions.
• Be sure to inspect the cam follower lobe for scoring or wear
when replacing a faulty lifter. Camshaft specifications can
found below under Valve Mechanism Reconditioning.
Page 104
Cylinder Head and Valve Mechanism
Bleeding Air Trapped in Cylinder Head
(from Mid-1988 models-engine no.
J082586-and later)
The cylinder head introduced on mid-1988 and later models
uses small drilled oil passages to supply oil to the camshaft
and cam followers. In some cases, it is possible for air to become trapped due to the tight tolerances of the passages. If
more than one follower is noisy even after running the engine
for more than a half-hour, try bleeding the lubrication system
as described below.
NOTE
• On earlier cylinder heads (up to engine no. J082585), oil to
the followers is supplied via oil pipes. Trapped air has not
been a problem on cylinder heads with external oil pipes.
• See 100 Fundamentals for the Do-it-yourself Owner for
engine number location.
To bleed lubrication system
1. Remove the valve cover as described below in Valve
Mechanism.
2. Loosen (three or four turns) the black bolt on the no. 5
intake camshaft bearing cap. See Fig. 2.
214-3
NOTE
Place some clean shop towels in the spark plug recesses to
catch any spilled oil.
4. Disable the ignition by removing the harness connector
from the EZK amplifier (normally-aspirated models) or
the ignition control unit (turbo models).
NOTE
The EZK amplifier and the ignition control unit are mounted on
the left-hand (driver's) side fender. See 340 Ignition System
for exact component location.
5. Make sure the car is in neutral. Then crank the starter
motor for 15 seconds. Wait about 30 seconds. Repeat
this procedure two or three times.
6. Remove the valve cover and inspect the loosened
camshaft bearing cap bolt. There should be evidence
that oil has been forced passed the bolt. Tighten the
bolt.
Tightening torque
• camshaft bearing cap
to cylinder head
15 Nm (11 ft-Ib)
7. Remove the shop towels from the spark plug area and
clean up any spilled oil.
8. Thoroughly clean the valve cover gasket surface and
reinstall the valve cover using a high-temperature silicone sealer as described below in Valve Mechanism.
9. Start the engine. The noise should go away within a
few minutes.
NOTE
If the cam follower noise does not go away, it is most likely
faulty and should be replaced as described earlier.
Fig. 2. Black bolt on no. 5 intake camshaft bearing cap (arrow).
3. Install the valve cover using at least one top bolt and
one bottom bolt.
HYDRAULIC CAM FOLLOWERS
Page 105
214-4
Cylinder Head and Valve Mechanism
VALVE MECHANISM
Fig. 3 is an exploded view of the valve mechanism and cylInder head assembly.
To remove and install valve cover
1. Remove the two screws and center cover from above
the spark plugs. See Fig. 4.
2. Remove the spark plug wires from the spark plugs and
remove the wires with the grommet from the valve cover.
3. Remove the outer and inner valve cover mounting bolts
and remove the cover and two cover gaskets.
4. Thoroughly clean the gasket surfaces of the cover and
cylinder head. Install the new gaskets to the cylinder
head. Then apply a 1/8 in. bead of high-temperature silicone sealer (Bostik Silicone 2680 or equivalent) at the
three split plugs and above the distributor. See Fig, 5.
5. The remainder of installation is the reverse of removal.
Tighten the mounting bolts in stages until the final
torque is reached.
Valve cover
Oil spray bar assembly
(1985-mid 1988)
Camshaft bearing cap
1--+-----:7 Camshafts
Valve guide
~
. .,.,~_ --_J Camshaft timing
~- '~~q-) chain tensioner
Valves
87015-5211561
Fig. 3.
Exploded view of valve mechanism and cylinder head,
VALVE MECHANISM
Page 106
---Cylinder Head and Valve Mechanism
214-5
CAUTION
If the camshaft timing marks shown below are not exactly
aligned, the timing chain or one of the sprockets may be severely worn or the timing chain may have jumped out of position. See 215 Camshaft Timing Chain. for additional
information.
I--------·---------======;::::--------j
Fig. 4.
I
i
I
I
I
'
Center spark plug cover being removed.
L
.
Fig. 6.
B7243
B_7~244 -S2~~~
Flywheel 0° TOC mark aligned with timing mark on engine
end plate (arrows).
I
Fig. 5. Areas of valve cover gasket requiring high-temperature silicone sealer.
Tightening Torque
• valve cover to cylinder head
15 Nm (11 ft-Ib)
To remove and install camshafts (cylinder
head installed)
1. Remove the valve cover as described above.
2. Set the engine to TOG by rotating the crankshaft in
normal engine rotation until the "0'" mark on the flywheel is aligned with the timing mark on the end plate.
See Fig. 6.
NOTE
Check also that the marks on the camshafts are aligned with
their matching marks on the bearing caps. See Fig. 7. If the
marks are not aligned, tum the engine over an additional 360°
(1 revolution).
B7245-S2/267
Fig. 7. Camshaft timing mark aligned with mark on camshaft bearing
cap.
3. Remove the ignition distributor as described in 340 Ignition System.
4. Remove the external oil supply pipes from the cylinder
head. if applicable. See Fig. 8
VALVE MECHANISM
Page 107
214-6
Cylinder Head and Valve Mechanism
CAUTION
Do not rotate the engine if the camshaft timing chain is removed from either camshaft. The pistons can hit the valves
and damage them.
CAUTION
Do not twist the pipes when removing them. This may damage
the sealing surfaces between the pipes and the fittings.
NOTE
Beginning in mid-1988, a new cylinder head was used and the
extemal oil supply pipes were discontinued.
NOTE
If removing both camshafts, insert a stiff wire through the
chain to prevent it from falling into the timing chain cover area.
Installation is the reverse of removal. If removed, be sure to
refit the hydraulic cam followers in their original positions.
Make sure the flywheel is set at the TOC mark (shown in Fig.
6 above). Install the camshafts such that the timing marks are
correctly aligned (shown in Fig. 7 above) before tightening the
camshaft bearing caps. When installing the camshaft bearing
caps, make sure all numbers on the caps align with their numbers on the cylinder head, if applicable. Install the black camshaft bearing cap bolts on the spark plug side of the cap. See
Fig. 10. Make sure the oil spray bar is correctly aligned with
the bar's fittings (see Fig. 22 given later).
CAUTION
The black camshaft bearing cap bolts are drilled to provide oil
passages to the hydraulic cam followers and must always be
installed on the spark plug side of the cap ..
Fig. 8. Oil supply pipes for hydraulic cam followers being removed
on mid-1 988 and earlier cars.
5. Working from the side of the cylinder head, remove the
camshaft timing chain tensioner. See Fig. 9.
--;'1
I
I
I
87247-52/259
"-----___________________
I
Fig. 10. Special black camshaft bearing cap bolts must be installed
on spark plug side of cap.
Fig. 9. Camshaft timing chain tensioner being removed.
6. Carefully unbolt the camshaft bearing caps evenly until
all valve spring pressure is relieved. Remove the camshaft by lifting the chain off the sprocket.
VALVE MECHANISM
NOTE
Bearing caps marked with numbers 1 through 5 are used on
the intake camshaft and 6 through 10 are used on the exhaust
camshaft.
Page 108
Cylinder Head and Valve Mechanism
214-7
Make sure all of the timing chain slack is on the tensioner
side of the chain and install the chain tensioner. Turn the engine over several revolutions in the direction of normal rotation and bring it back to TDC. Double check all timing marks. If
necessary, remove the tensioner and reposition the chain on
the sprockets. Install the valve cover using new gaskets and
sealer as described earlier. Install the distributor and ignition
wires as described in 340 Ignition System.
CAUTION
Correct camshaft timing is critical. If the timing chain is off by
as little as two teeth on the sprocket, the pistons can contact
the valves. Always check and recheck camshaft timing by
turning the engine over by hand.
Tightening Torques
• camshaft bearing caps
to cylinder head
• camshaft timing chain tensioner
to timing case
• valve cover to cylinder head
15 Nm (11 ft-Ib)
63 Nm (46 ft-Ib)
15 Nm(ll ft-Ib)
Fig. 11. Cam follower being removed from cylinder head.
To replace valve stem oil seals
(cylinder head installed)
The procedure below covers valve stem oil seal replacement with the cylinder head installed, using Saab special tools
and a source of compressed air. The oil seals can also be replaced as part of the disassembly/assembly procedure described later under this repair group.
1. Set the engine to TDC and remove the camshafts as
described earlier.
2. Using a magnetic tool, extract the cam followers. Label
each follower so that they can be reinstalled in their
original positions. See Fig. 11
CAUTION
The cam follower bores create a sealing surface for the cam
followers. These surfaces must not be scratched or scored.
Special plastic protector sleeves are available from an authorized Saab dealer (special tool no. 83 93746). See Fig. 12.
3. Remove a spark plug from the cylinder head. Thread
an appropriate adapter into the spark plug hole and
connect the compressed air line to the adapter. Raise
the air pressure in the cylinder.
Fig. 12. Plastic sleeves being installed in cylinder head to protect cam
follower bores,
NOTE
The spark plug hole adapter is available under Saab special
tool no. 8392 326.
4. Place Saab special tool 83 94 181 on top of the valve
spring retainer. See Fig. 13.
5. Firmly tap the tool so that the valve spring keepers
come free and follow the tool out. See Fig. 14.
VALVE MECHANISM
Page 109
214-8
Cylinder Head and Valve Mechanism
Fig. 13. Special Saab tool installed on top of valve spring retainer,
Fig. 14. Removed valve spring keepers in special tool.
Fig. 15. Valve stem oil seal removed with special pliers,
Fig. 16. Valve stem oil seal being installed into special tool.
6. Lift out the valve spring retainer and the spring. Then
using valve stem oil seal removal pliers, remove the
seal. See Fig. 15.
7. Using Saab special tool83 93 803, insert the new valve
stem oil seal into the tool. See Fig. 16.
8. Fit the seal into position and gently tap on the tool until
the seal is firmly seated. See Fig. 17.
9. Install the spring and the spring retainer. Fit the valve
keepers into position on the valve spring retainer.
10. Place Saab special tools 83 94 181 and 83 94207 onto
the valve spring retainer and tap the tool firmly to seat
the keepers in the keeper grooves. See Fig. 18.
Fig. 17. Valve stem oil seal being installed on valve guide,
11. Repeat the above procedures for the remaining valve
stem oil seals.
VALVE MECHANISM
Page 110
Cylinder Head and Valve Mechanism
214-9
CAUTION
The cam follower bores create a sealing surface for the cam
followers. These surfaces must not be scratched or scored.
Special plastic protector sleeves are available from an authorized Saab dealer (special tool no. 8393746). See Fig. 12 given earlier.
6. Remove the valves, the valve spring retainers, the
valve springs, and the spring seats. Label each complete assembly as it is removed.
NOTE
A valve spring compressor adaptor or a special valve spring
Fig. 18. Hammer and special tools being used to install valve
spring keepers.
compressor is needed to depress the valve springs. Saab
special valve spring compressor (Saab tool no. 83 93 761 or
KD tool no. 308) and special anvil (tool no. 83 93 779) are
shown below in Fig. 19.
12. Remove the plastic sleeves and fit the cam followers
into their original positions. Install the camshafts and
valve cover as described above.
To disassemble valve mechanism
(cylinder head removed)
NOTE
Cylinder head removal and installation is covered under 211
Cylinder Head Removal and Installation.
1. Remove the ignition distributor as described in 340 Ig
nition System.
2. Remove the intake and exhaust manifolds from the cylinder head.
Fig. 19. Special valve spring compressor (A) and anvil (B) being used
to remove valve.
3. If applicable, pull the oil spray bar assembly from the
top of the cylinder head.
WARNING
CAUTION
Do not twist the spray bars during removal. This can cause
damage to the mating surfaces between the bars and the fittings.
4. Remove the camshaft bearing caps. Label each cap so
that they can be reinstalled in their original positions.
Remove the camshafts.
5. Using a magnetic tool, extract the cam followers. Label
each follower so that they can be reinstalled in their
original positions.
The valve springs are under considerable pressure. Use extreme care when removing the valves. Wear hand and eye
protection.
7. Remove the valve stem oils seals using valve stem oil
seal removal pliers. See Fig. 20.
Cylinder head assembly is the reverse of disassambly. Prior to installation, inspect all components for wear as desCribed below. Be sure all parts are installed in their original
positions. Lubricate the camshaft, the valve stems, and the
valve stem oil seals prior to installation. Always use new valve
VALVE MECHANISM