oil pressure OPEL MANTA 1973 Owner's Manual

6A- 261973 OPEL SERVICE MANUAL
rear of cylinder head. Remove camshaft toward
front, supporting camshaft with one hand through
access hole and taking care not to damage bearing
surfaces. See Figure 6A-43.12345 6
I. OLD PRESSURE
4. COVER GASKET
RELIEF
~~- \SSEMBLY5. COVER 8 VALVE
ASSEMBLYVALVE I
2. TIMING CASE
6. COVER ATTACHING
3. OIL PUMP GEARS
SCREWS
123” 45Figure 6A-44 Oil Pump Components
1.CAMSHAFT
2. FRONT ACCESS HOLE
3. LATERAL ACCESS HOLE
4. CYLINDER HEAD
5. REAR ACCESS HOLEISA-43
Figure 6A-43 Removing Camshaft
Installation
1. Liberally lubricate camshaft journals and install
camshaft from front into cylinder head. Support
shaft through access hole in left side of head to pre-
vent damaging bearings.
2. Reinstall valve lifters, rocker arms and self- lock-
ing rocker arm nuts.
3. Install rear and side access plates.
4. Reinstall cylinder head.
OIL PUMP COVER AND GEARSRemoval and Installation of Oil Pump
Cover and Gears
1. Remove screws attaching oil pump cover assembly
to timing chain cover. Remove cover assembly and
slide out oil pump gears. See Figure 6A-44.
2. Wash off gears and inspect for wear, scoring, etc.
Replace any gears not found serviceable. Discard
pump covers scored by gear action. If pump housing
or distributor drive shaft bushing are worn (this is
only possible after a long service life), the timing case
together with all exchangeable pump parts have to be
discarded.In isolated cases, timing cases are installed in pro-
duction having
.008 in. oversize bores for pump gears
and shafts. Oversize bores may exist either for one or
both gears; these timing cases are identified by the
number “0.2” stamped into pump flange on left and-
/or right-hand side. Oversize replacement gears
should be selected according to Part Catalog specifi-
cations.
3. Liberally lubricate spindles and gear teeth and use
new cover gasket. Install oil pump cover.
If new gears are installed, their end clearance in a dry
pump housing should be checked with a straight
edge and a feeler gauge. The gears must not protrude
more than X04 in. over pump housing. See Figure6A-45.
FEELER
AUGESTRAIGHTIEDGE
Figure 6A-45 Checking Oil Pump Gear End Clearance

ENGINE MECHANICAL AND MOUNTS6A- 27
With feeler gauge, check gear backlash. It should be
between
.I?04 in. and .C!OS in. See Figure 6A-46.3. Remove (2) bolts holding pipe and screen assem-
bly to cylinder block. See Figure 6A-47.
FEELERGAUGE6A-46
Figure 6A-46 Measuring Oil Pump Gear Backlash
Checking Oil Pump Relief Valve
For Proper Functioning
1. Unscrew plug and check spring and relief valve
plunger in oil pump cover for dirt particles and free
operation. If required, carefully clean plunger and
seat. Pressure relief plunger sticking as a result of
foreign material or sludge build-up in the oil pump
cover can cause loss of oil pressure.
Removal and Inspection of Oil Pump
Pipe and Screen Assembly
1. Remove oil pan.
2. Clean oil pan. Make sure the gasket surfaces and
pan and block are clean.
Figure 6A-47 Installation of Pipe and Screen
Assembly4. Clean the screen and housing thoroughly in sol-
vent and blow dry with air stream.
Installation of Oil Pump and Screen Assembly
Install by reversing removal procedures, paying par-
ticular attention to the following points.
1. Make sure oil pump pipe flange gasket surface of
block is smooth and free of dirt.
2. Use a new gasket and install assembly.
3. Tighten pan bolts evenly. Do not over-tighten.
Torque to 5 lb. ft.
SPECIFICATIONSBOLT TORQUE SPECIFICATIONS
Use a reliable torque wrench to tighten all parts listed, to insure proper
tightness without straining or distorting parts. These specifications are for
clean and lightly-lubricated threads only; dry or dirty threads produce in-
creased friction which prevents accurate measurement of tightness.

6A- 28 1973 OPEL SERVICE MANUAL
Part
ConnectingRod Bolts..........................................................
Crankshaft Main Bearing Bolts
..........................................
FlywheeltoCrankshaft AttachingBolts..........................
Cylinder Head Attaching Bolts....Cold 72 -Warm 58
Camshaft Sprocket Attaching Bolts................................
Generator Bracket to Cylinder Block
Attaching Bolts ..................................................................
Generator Bracket to Timing Case Attaching Bolts
....
Crankshaft Pulley Attaching Bolts ....................................
Rocker Arm Stud in Cylinder Head ..................................
Spark Plugs ........................................................................\
....
Clutch Housing to Cylinder Block Attaching Bolts
......
Timing Case to Cylinder Block AttachingBolts ............
Water Pump to Timing Case AttachingBolts................
Engine Support to Cylinder Block Attaching Bolts
......
Rear Engine Suspension to Transmission Rear Bearing Retainer Bolts ....................................................
Transmission to Clutch Housing Attaching Bolts
........
Starter to ClutchHousing AttachingBolts....................
Support to Starter Attaching Nut
....................................
Intake and Exhaust Manifold to Cylinder Head Attaching Bolts ..................................................................
Unless Otherwise Noted:
10
@i Bolt (15 MM Hall.....................................................................- -
36
72
43
18
;i
72
29
30
36
14
11
40
22
29
40
4
33 ............30
8 MM Bolt (13 MM Head)........................................................................\
........................................................................\
........................................15
6 MM Bolt (10 MM Head)
30 Lb.In.
Torque
Lb.Ft.
GENERAL SPECIFICATIONS
Type - No. of Cylinders
Valve Arrangement........................................................................\
........................................................................\
......................................................I;nlinzai
Bore and Stroke Piston Displacement Cu. In.
........
3.66 x1:;:;
Compression Ratio......................................................................................\
........................................................................\
........................................................................\
........................................
\fô\
²…..............7.6:1Octane Requirement........................................................................\
..........
Firing Order........................................................................\
........................
Regular - Lo;-?::
....................Cylinder Block Material....... ...............................................................................\
..............................................Cast Iron
Crankshaft Bearings Number and Type 5 Removable Steel Backed
In-Metal Babbitts
Bearing Which Takes End Thrust
........................................................................\
...................5
Connecting Rod Bearing Material
........................................................................\
..................
Steel Backed Tri-Metal Babbttts
Piston Material and Surface Aluminum Alloy, Lead Coated
Piston Pin Offset
........................................................................\
............,031 In. to the RightCompression Rings Material and Surface Treatment
No.
1....... ........... ............... ........ ............. ................Chrome-plated, Cast Iron
- Rectangular
No. 2
........................................................................\
..............................Cast Iron - Tapered
Oil Ring
........................................................................\
..................Chrome-plated, Cast Ir?n
Location of All Piston Rings
........................................................................\
Above Ptston Pm
Camshaft Material
........................................................................\
....................Alloy Cast Iron
Camshaft Drive........................................................................\
........................................Chajn
Number and Type of Camshaft Bearings 4 Steel-Backed Babbttt
Valve Lifter Type
..............................................................................................\
..........................................~..........Hydraulic
Oiling System Tvoe........................................................................\
Circulatmg High Pressure
Oil
&ppiied to: - .
Bearing Surfaces, Crankshaft, Camshaft and Connecting Rods............................Pressure
Piston, Pins
........................................................................\
............................................Vapor
Cvlinder Walls........................................................................\
..........................Nozzle Spray
Rocker Arms _,,,..,,....,._..___.,,..,,..............,,,,...,.......,..,,,.,.,,.....\
....,,...,.,.................~...... Pressure
Oil Reservoir Capacity
- Quarts .,,,...,,__.,,..,..,,..,...,..,,,...,,..............,,,... 3 l/4 With Dry Fdter
Oil Filter
- Type ,,....,__.,,...,....,....,,..,,,..,,...........,........................\
............ Throw Away Element

ENGINE MECHANICAL AND MOUNTS6A- 29
Cooling System - Type ,._...___..___..___........................... Liquid Cooling With Circulating Pump
Filler Cap Type
- Pressure _,._.,,._.,,...,,.........,..,.....,.,.................,,......................... 13.2-15.2 PSI
Water Temperature Control
._,..__,,._.,,__.,,...,.,.,,.,,.,,.,...............,,...,,,... Thermostat and Bypass
Thermostat Open At
._,,.,,.......,__.,.........,,...,...,,..,.,,.,,...................................................... 189 F.
Cooling System Capacity
. . . . . . . . . . . . .._...__..............,,.,,.,,..,...................................,,................6 Qts.
Fan Drive
.,,...,,,....,,.,..,..,,........,..,,..,,,.............,..,,.,..,,.................,,............... Water Pump Shaft
ENGINE DIMENSIONS AND FITS
Cylinder, Crankcase, Pistons, Cylinder Head, Valves
Cyg;te; Bore Limits for Standard Size Pistons:3.659-3.660 In.
Size 23.661-3.663 In.Size 3
3.664-3.668 In.Cylindey Bore Limits for Oversize Pistons,
.02 In.Oversm
. .._............,..,,...,................................,,.,,.,,.........................................3.679-3.681 In.
Max.PermissibleCylinderBoreOut-of-Roundness
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..~.OOO5In.Max.Permissible Cylinder Bore Taper
,.., ,.,, ,.,._,__. ,_, ,.. .__... ..__. ,__. .____. ..__. .._..0005In.Piston Clearance, Nominal (on skirt bottom)
_..__,,_.,.___.__.._...........,.......................... .0014 In.No. 1 Compression Ring Side Clearance in
Piston Groove
,...,,,.,,,.,,...,__..........,,..,,...,,...,..,.,,.,,..,,..,,..,,..................,,,..,,,..., .0024-.0034 In.
No. 2 Compression Ring Side Clearance in
Piston Groove
_..,,..,,,..,,..,,..,,....,.......,...,,,.,.,,,..,..,..,,..,,..,,,..,,,.,,,..,,,...,,,..,,,,..., .0013-.OO24 In.
Oil Control Ring Side Clearance in Piston
Groove
__..__..._..,,,..,...,,,..,....,..,,..,.........,..,,...,,.,,.,,..,..,,..,,...,,...,,,..,,,..,,,...,,..... .0013-X024 In.
Piston Ring Gap:
No. 1 Compression Ring
..,,.,,,..,,,..,,..,,,.,,.,,,..,......,,.,..............,......................... .014-,022 In.
No. 2 Compression Ring
_..___..__.,,..,,..,,,..,.,,,..,,.,,....................,......................... .014-,022 In.
Oil Control Ring
,...,,...,___.___.._..................,,,..,..,,..,,.,,,..,,,.,,..,,,..,,,...,,,,..,,,...,.... ,015.,055 In.
Piston Pin in Connecting Rod
..____.___..._,,__.,,,,,..,,.,,..,.................,,............................... Press Fit
IntakeExhaust
Valve Spring Pressure
Valve Closed
_______........___..,,,,,,............1.57 In. at 93 Lbs.1.36 In. at 97
Lbs.
ValveOpen. . . . . . . . . . . . . . .1.18 In. at 182 Lbs..96 In. at 180
Lbs.
Valve Stem Diameters
Standard
Size. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..3538-.3543 In..3524-.3528 In.,003 In. Oversize
____.....__.._..,,,,,,.........3567-.3572 In..3553-.3559 In..0059 In.
Oversze .__......_______...............3597-.3602 In..3583-.3588 In.
.O 1 18 In. Oversize
_._...._._____...............3656-.3661 In..3642-.3647 In.
Valve Length, Nominal
..___.............4.843 In.4.92 In.
Valve Head Diameter
___.......____...,,,........1.574 In.1.34 In.Valve Guide Bores in Cylinder Head (Intake and Exhaust)
Standard Size
,,...,,...,,..,,..,,,..,,....................................,..,,...,,.,,,,..,,,,..,,...,,,,.., .3553-.3562 In.003 in Oversjze
.,..__,,._.,__..___....,,...,,..,,...,,,,,,.,,.,,..,................,.....,................. .3582-.3592 In.
,006 in Overslze
..,...,,..,,.......................................,.........................................3615-.3622 In.
.0118 in Oversize ,._.,,..,............,,...,,........................................,,.................... .3671-.3681 In.
Valve Stem Clearance
Intake .
.._........___..___.....,............,...,,..........................................,,...................... .OOl-.0029 In.
Exhaust
._.,,........,,...,,..,,...........,,...,................,..,,..,,................,,.....,.,........................ 0039 In.
Max. Permissible Head to Stem Runout
Intake
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..OO16In.Exhaust
.,...........,,...,...,.,,...........,,...,....,....,.,,,..,,.,,,........................................,.......... .0019 In.

GA. xl1973 OPEL SERVICE MANUAL
Valve Seat and Correction Angle in Cylinder Head
Intake
Valve Seat Angle ..,._,..__....,,..,,,..,.,.,.,..............,............................................................... 45”Outer Correction
.,,,.,,._.,._..___,,,.,,,,,.......,,.,..,...,,..,..,,..,,..,,,.............................................. 30”
Exhaust
Valve Seat Angle
,,,.,,.__,.__..___.,..,,..,...,,....,..,..,..,,..,..,...,..,,,...,,......................................... 45”
Outer Correction
.,,..,,...,._.,.__....,,,.....,,,........................................................................... 30”
Valve Face Angle
,,..,,,..,.__..__.._..,,,..,,...,,......,.,..,..,..,,.,,,..,..,,,..,,,..,,,...,,................................ 44”Valve Seat Width in Cylinder Head
Intake
. . . . . . . . . . .._..._._.................,,..,.....,,..,............,...,..,,,..,,..,,...,,...,,,..,..................049-,059 In.
Exhaust
.,..,,,..,,.___..,,..,,...,..,,,..,,...,,...,,...............,,..,,..........,,....,,...,..................... .063-,073 In.Valve Head Contact Area
,,..,,,..,,___.__.,,..,,..,.,,..........,...,,..,,............,,,...,....... Aim at Centricity
Valve Clearance at 176°F. Coolant and 140°F. to 176”
Oil Temperature
Intake and Exhaust
_.,,..,,,,,,..,,....,...,,,.,.,,,.,..........................,,,..,,,,.... Zero Plus One Turn
Cranking MechanismMax. Permissible Out-of-Roundness of Connecting Rod Bearing
Journals
.....................................................................................................................OC02 In.
Max. Permissible Taper of Connecting Rod and Crankshaft Bearing
Journals
.....................................................................................................................ooO4 In.
Max. Permissible Radial Runout of Center Main Bearing
JournalsWhenSupportedinEndBearings
...........................................................0012In.Max. Permissible UnparalYelism of Connecting Rod Bearing
Journals When Crankshaft is Placed in V-Blocks so That
Main Bearing Journals Next to Each Other Are Supported
................................0005 In.
Max. Permissible Runout of Crankshaft to Flywheel
Contact Area
...........................................................................................................0008 In.
Crankshaft End Play
.........................................................................................GOl7-.CO61 In.
MainBearingClearance
.....................................................................................ooO9-.@I25In.Connecting Rod Bearing Clearance
.................................................................ooO6-.0025 In.
Connecting RodEnd PlayonBearing Journal
...............................................0043-.0095In.Connecting Rod Bearing Length
.......................................................................7785-.7992 In.
CrankshaftThrustBearingLength
..............................................................................1.08In.
Valve MechanismCamshaft Bearing Clearance
.................................................................................OOl-,003 In.
Camshaft End Play
...............................................................................................004-038 In.
Max. Permissible Radial Runout of Camshaft Center Bearing
- Camshaft Supported in Outer Bearings................................................................,001 In.
ValveLifter Clearance in Cylinder HeadBore
...............................................0003-.OOl3In.
Engine Lubricating SystemOil Pump Gear Backlash
......................................................................................0%.008 In.
Oil Pump Gear End Play in Housing
........................................Gears Protruding Over Edge
of Housing: Not More Than
,004 In.
Clearance of Spindle in Bore of Oil Pump Driven
Gear
...............................................................................................................OCO3-.0015 In.
Clearance Between Oil Pump Drive Gear and
Bushing
.........................................................................................................00035-.OOl5 In.
Oil Pump Relief Valve Spring Pressure at a Spring Length
of
.8 In..................................................................................................................44-.66 Lbs.

66.321973 OPEL SERVICE MANUAL
COOLING SYSTEM
CONTENTS
Subject
DESCRIPTION AND OPERATION:
Cooling System and Water Pump
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .DIAGNOSIS: (Not Applicable)
MAINTENANCE AND ADJUSTMENTS:
Checking and Filling Cooling System
. . . . . . . . . . . . . . . . . . . . . . . .Draining
andFlushingCoolingSystem. . . . . . . . . . . . . . . . . . . . . .Conditioning the Cooling System
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Using and Testing Anti-Freeze Solutions
. . . . . . . . . . . . . . . . . .Fan Belt Adjustment or Replacement
. . . . . . . . . . . . . . . . . . . . . . . .Radiator Thermostat Inspection and Test
. . . . . . . . . . . . . . . .MAJOR REPAIR:
Water Pump Removal
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Radiator
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SPECIFICATIONS:
Cooling System Capacities
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page No.
68-32
6B-32
68-32
68-33
68-33
68-33
68-33
68-34
68-34
6B-35
DESCRIPTION AND OPERATION
COOLING SYSTEM AND WATER PUMPThe coiling system is of the conventional pressurized
type. A centrifugal pump arranged in timing case
serves to circulate the coolant.
When the thermostat is closed, the coolant will re-
turn to the pump via a by-pass for swift and uniform
warming up of the engine the coolant circulates
through the radiator, only when the engine has
reached normal operating temperature.
The heater system branches off the cooling system
ahead of thermostat in flow direction so that the
heater is in operation before engine has reached full
operating temperature.
MAINTENANCE AND ADJUSTMENTS
Checking and Filling Cooling SystemThe coolant level should be checked only when the
engine is cold and only enough coolant should be
added to bring the level halfway between core andtank top. It is unnecessary and undesirable to remove
the radiator cap and check the coolant level each
time the car stops at a filling station for gasoline or
oil, since the engine is usually hot at such times.
WARNING: Never remove the radiator cap quickly
when engine is HOT Sudden release of cooling
sys-
tern pressure may cause the coolant to boil and some
of it may be ejected from the radiator
filler neck,
resulting in
inl’ury to persons or damage to the car
finish.If it is necessary at any time to remove the radiator
cap when engine is hot, rotate the cap counterclock-
wise until first stop is reached. Leave cap in this
position until all pressure in cooling system has been
released, then turn cap past the first stop and remove
it.
Draining and Flushing
Cooling SystemThe cooling system should be completely drained
and the recommended coolant installed every two (2)
years.To drain the cooling system, remove radiator cap,
remove lower radiator hose from the lower tank and

6G- 661973 OPEL SERVICE MANUAL
6. Check compression of each cylinder. Repeat
compression check and record highest reading ob-
tained on each cylinder during the two pressurechecks.The recorded compression pressures are to be con-
sidered normal if the lowest reading cylinder is more
than 75 percent of the highest reading cylinder. See
the following example and the “Compression Pres-
sure Limit Chart.” See Figure
6G-2.Seventy-five percent of 140 (highest) is 105. Thus,
cylinder No. 4 is less than 75 percent of No. 3. This
condition, accompanied by low speed missing, indi-
cates an improperly seated valve or worn or broken
piston ring. See Figure 6G-1.
23
I
SO-1Figure 6G-1 Example of Compression Check
7. If one or more cylinders read low, inject about a
tablespoon of engine oil on top of pistons in low
reading cylinders through spark plug port. Repeat
compression check on these cylinders.
a: If compression improves considerably, rings are
lV0*tl.b. If compression does not improve, valves are stick-
ing or seating poorly.
c. If two adjacent cylinders indicate low compression
and injecting oil does not increase compression, the
cause may be the head gasket leaking between the
cylinders. Engine coolant and/or oil in cylinders
could result from this defect.
Compression Pressure Limit ChartThis chart may be used when checking cylinder com-
pression pressures. It has been calculated so that the
lowest reading number is 75 percent of the highest
reading number. See Figure 6G-2.
EXAMPLE: After checking the compression pressures
in all cylinders, it was found that the highest pressure
obtained was 182 psi The lowest pressure reading
was 145psi.
By locating 182 in the maximum col-
umn, it is seen that the minimum allowable pressure
r-.__MAXIMUM
PRESSURE
POIJNWW. INCH
--
134
136
138
140
142
146148
150
152
154
156
158160lb2
164166168170172
174
176
178
180182184
186MINIMUM
PRESSURE
POUNDS/
SQ. INCHHAXIMUM
‘RESSURE
‘OUNWiQ. INCHMINIMUM
PRESSURE“OUNWX?. INCH
101188I41I02190142104192144105194145107196147II0198148Ill200150
113202151
114204153
115206154
117208156118210157120212158
121214160123216162
124218163
126220165127222166129224168131226169132228171133230172
135232174136234175138236177140238178
Figire 6G.2 Compression Pressure Limit Chart
is 136psi. Since the lowest reading obtained was 145
psi,
the car is within limits and the compression is
considered satisfactory.
Spark Plugs1. Inspect, clean and regap or replace spark plugs as
required. Correct gap is
,030.2. Install spark plugs. Tighten to 30 lb.ft.
Secondary Ignition System1. Inspect ignition cables for broken, swollen or
deteriorated insulation.
2. Check terminal ends and condition of rubber
boots. Replace as required.
3. Inspect the condition of the distributor cap and
rotor.
4. Clean the ignition coil and inspect for cracks or
carbon paths which could cause high voltage leak-
age.
Distributor Contact Points1. Inspect distributor contact points and replace or
adjust as necessary
(.016 gap).

2. If inspection of contact points indicates excessive
burning, pitting or wear, check condenser and re-
place if necessary.
3. Inspect all connections and wires in the primary
ignition circuit. Correct any abnormal conditions
found.Carburetor1. Clean fuel strainer in fuel pump. To prevent fuel
leakage in pump, disconnect “IN” line from pump
and raise end above fuel level. The in-line fuel filter
should be replaced every 12,000 miles or every 12
months.
2. Check for freedom of choke valve operation and
clean shaft if necessary, with suitable solvent.
3. Inspect throttle cable or linkage bracket and re-
turn spring for wear. With helper depressing acceler-
ator pedal to floor, check for wide open throttle.
Adjust accelerator pedal height so wide open throttle
is obtained when pedal is within
l/2 inch from floor.
Lubricate linkage pivot points with engine oil.
Air CleanerCheck paper element every 6,000 miles and replace
every
24,ooO miles. If a vehicle is operated in dusty
territory, check condition of air cleaner element
more frequently and replace if necessary.
Fan Belt1. Inspect belt for wear, cracks or frayed points.
Replace and/or adjust as necessary. Specified ten-
sion for belt using Gauge J-23600 is 45 lbs.
Cooling System1. Inspect the radiator, water pump, cylinder head
areas and all radiator and heater hose connections
for evidence of engine coolant leaks.
2. Inspect all hoses for deterioration from gas and oil
contact. Correct as required.
Inspection should be made with engine operating at
normal temperature, cooling system completely
filled, temperature control lever fully open and nor-
mal pressure in the system. Normal pressure should
be 13.2 to 15.2 psi.
Engine Lubrication SystemInspect engine for evidence of oil leakage. Correctany abnormal condition with sealastic or new seals
and gaskets.
Battery
1. Inspect battery, battery mount and cables and
check electrolyte level. Proper level should be just
above the cell plates.
CAUTION:Do not over fill.
2. Determine the serviceability of the battery by ap-
plying the 421 Battery Test.
Positive Crankcase VentilationClean crankcase ventilator metered orifice in the in-
take manifold fitting every 6,000 miles. Also all hoses
and fittings should be inspected, cleaned and re-
placed, if necessary.
To clean, remove rubber hose from metered orifice
and apply air pressure to orifice to remove any for-
eign particles that may be trapped.
Valve Lifter AdjustmentRefer to Engine Mechanical and Mounts section for
valve lifter adjustment procedure.
Engine Tune-Up Instrument ChecksThe following instrument checks and adjustments
serve as a final check on engine condition. These
checks may discover some new problems that may
not have been obvious before. The engine is also
given its final adjustments that will assure maximum
performance, reliability, and proper emission con-
trol.
Refer to Electrical Group for checking procedures of
the following:
Cranking Voltage Check
Ignition Timing
Distributor Advance
Ignition Output
Secondary Resistance
Current Output and Voltage Setting
Idle Speed and Mixture AdjustmentsRefer to carburetor section.

7A- 21973 OPEL SERVICE MANUALDIAGNOSIS
CLUTCH TROUBLE DIAGNOSIS
ConditionPossible Cause
CorrectionFails to release (pedal
1. Improper cable1. Adjust cable.
pressed to floor
- shiftadjustment.
lever does not move
freely in and out of
“Reverse” gear.
2. Faulty pilot bearing.2. Replace bearing.
3. Faulty driven plate.3. Replace driven plate.
4. Yoke off ball stud.4. Install properly.
5. Clutch driven plate hub5. Repair or replace main drive
binding on main drive gear
gear.spline.
Slipping1. Improper adjustment (no1. Adjust cable.
lash).2. Oil-soaked driven plate.2. Install new driven plate and
correct oil leak at its source.
3. Worn facing or facing3. Replace driven plate.tofn from driven plate.
4. Warped pressure plate or4. Replace same.
flywheel.
5. Weak diaphragm spring.5. Replace cover assembly.
6. Driven plate not seated6. Make 20-50 normal starts.
in.7. Driven plate overheated.7. Allow to cool
- check lash.
Grabbing1. Oil on facing or burned1. Repair oil leak and install
or glazed facings.new driven plate.
2. Worn splines on main2. Replace transmission main drive
drive gear.gear.
3. Loose engine mountings.3. Tighten or replace mountings.
4. Warped pressure plate or4. Replace pressure plate or
flywheel.flywheel.
5. Burned or smeared resin5. Sand off if superficial, replace
on flywheel or pressureburned or heat checked parts.
plate.

CLUTCH7A- 3Possible CauseCorrectionRattling
- Transmission
Click1. Yoke loose on ball stud
in bearing groove.1. Check ball stud and retaining
spring and replace if necessary.
2. Oil in driven plate
damper.2. Replace driven plate.
3. Driven plate damper
spring failure.3. Replace driven plate,
Throw-out bearing noise
with clutch fully
engaged.1. Improper adjustment.1. Adjust cable.
2. Throw-out bearing bind-
ing on transmission bearing
retainer.2. Clean, relubricate, check for
burrs, nicks, etc.3.
InsuffIcient tension
between yoke and ball stud.3. Replace yoke.
4. Yoke improperly
installed.4. Install properly.
5. Weak linkage return
spring.5. Replace spring.
Noisy1. Worn throw-out bearing.1. Replace bearing.
2. Fork off ball stud
(heavy clicking).2. Install properly.
Pedal stays on floor
when disengaged.1. Bind in cable.1. Lubricate and free up cable.
2. Spring weak in pressure
plate.2. Replace
3. Weak linkage return
spring.3. Replace
High Pedal Effort1. Bind in cable.
2. Driven plate worn.1. Lubricate and free up cable.
2. Replace driven plate.
Clutch facings worn near
rivets.1. Normal wear.1. Replace driven plate assembly
only, and readjust clutch pedal and
cable.
Pressure plate assembly
friction surface badly
scored or rough.1. Improper clutch pedal
lash causing pressure plate
to come in contact with
rivets.1. If roughness can be smoothed with
fine emery cloth, do not replace
pressure plate assembly; if it cannot,
replace the pressure plate and driven
plate assembly. Adjust clutch.