1973 OPEL GT-R check engine

6A. 61973 OPEL SERVICE MANUALDIAGNOSIS
EXCESSIVE OIL CONSUMPTION
ConditionCorrectionExternal Oil Leaks at:Tighten attaching bolts. If leaks
Rocker Arm Coverspersist, remove cover (or pan),
Crankcase Front Covercheck sealing surfaces for burrs
Oil Pan and Gasketor scoring, replace gasket, and
seal bolts with silastic sealer or
equivalent. Make sure oil level
,is not overfull.
Improper Reading of Dip-Car may not be level when taking r
StickInsuffIcient oil “drain-back” time
after stopping engine (three
minutes must be allowed). Dip-
stick may not be completely pushed
down against stop. Dipstick may
be bent.
Oil Viscosity Too LightUse recommended SAE viscosity for
prevailing temperatures.
Continuous High-SpeedAt speeds above 60 mph, increased
Drivingsumption can be expected with any
Inform customer of this fact.
High-Speed DrivingWhen principal use of automobile i
Following Normal Slowcity driving, crankcase dilution f
Speed City Drivingcondensation occurs. High speed a
temperatures will remove water,
resulting in what appears to be
rapid lowering of oil level.
Inform customer of this fact.
Piston Rings NotAllow engine to accumulate at leas
“Broken In”
4,OCO miles before attempting any
engine disassembly to correct for
oil consumption.
NOISY VALVES AND LIFTERSIf the preceding check indicates valve mechanism is
abnormally noisy, remove the rocker arm cover so
that the various conditions that cause noise may be
The noise level of the valve mechanism cannot bechecked. A piece of heater hose of convenient length
properly judged where the engine is below operatingmay be used to pick out the particular valves or valve
temperature when the hood is raised, or when thelinkages
thit are causing abnormal noise. With the
valve rocker arm covers are removed.engine running at a speed where the noise is pro-
nounced; hold the end of hose to an ear and hold
Before attempting to judge valve noise level, the en-other end about
l/2 inch from point of contact be-
gine must be thoroughly warmed up (at least 20tween rocker arm and valve stem. Mark or record the
minutes of operation at
1200 to 1500 RPM) to stabil-noisy valves for investigation of following causes:ize oil and coolant temperatures and bring all engine
parts to a normal state of expansion. When the
en-1. Sticking, Warped, or Eccentric Valves, Worngine is warmed up, listen for engine noise while
sit-Guides Sticking valves will cause irregular engine
ting in the driver’s seat with the hood closed. Run theoperation or missing on a low speed pull and will
engine at idle and at various higher speeds.usually cause intermittent noise.

ENGINE MECHANICAL AND MOUNTS6A- 7
Pour penetrating oil over the valve spring cap andengine off. It makes no difference whether the engine
allow it to drain down the valve stem. Apply pressureis cold or is at operating temperature. Set piston of
to the one side of the valve spring and then the other,the respective cylinder to upper top center on the
and then rotate the valve spring about l/2 turn. Iffiring stroke. This can be accomplished by removing
these operations affect the valve noise, it may bethe distributor cap and observing the rotor. Check
assumed that valves should be reconditioned.position of the rotor and follow spark path for the
2.Worn or Scored Parts in the Valve Train Inspectrotor tip through the distributor cap, high tension
rocker arms, push rod ends for scoring. Check pushwire to spark plug. This determines which cylinder
rods for bends, valve lifters, and camshaft surfacesis at upper top center on the firing stroke. Adjust the
for scoring. Replace faulty parts.hydraulic lifters of the two valves for that cylinder at
this time. When they are adjusted, turn engine so
MAINTENANCE AND ADJUSTMENTSthat another.cylinder is at upper top center on the
firing stroke and adjust the two valve lifters for that
VALVE LIFTER ADJUSTMENTcylinder. Repeat process until all valves are adjusted.
See Figure 6A-6 for correct rotor position for each
Perform hydraulic valve lifter adjustment with thecylinder.
CORRECT ROTOR POSITION TO ADJUSTCORRECT ROTOR POSITION TO ADJUST
VALVES ON CYLINDER NO. 1VALVES ON CYLINDER NO. II
CORRECT ROTOR POSITION TO ADJUSTCORRECT ROTOR POSITION TO ADJUST
VALVES
ON CYLINDER NO. IllVALVES ON CYLINDER NO. ,VW-6Figure
6A-6 Rotor Positions for Valve Lifter Adjustment

RECESSES VERTICAL FOR
REMOVAL OF LEFT ROW OF
CYLINDER HEAD BOLTS6A-16
Figure 6A-18 Recesses in Camshaft
2. Clean piston tops and combustion chambers.
Thoroughly clean all gasket surfaces on the cylinder
block and cylinder head.
3. Lightly lubricate cylinder walls with engine oil.
Install coolant passage rubber gasket ring in timing
case. See Figure 6A-19.I. TIMING CHAIN
2. CAMSHAFT SPROCKET
3. SPROCKET TIMING MARK
4. TIMING CASE5. SUPPORT TIMING MARK
6. SUPPORT
7. CYLINDER BLOCK
6. RUBBER GASKET RING6A-19
Figure 6A-19 Coolant Passage Rubber Gasket Ring in
Timing CaseENGINE MECHANICAL AND MOUNTS
6A- 13
4. Apply silastic sealer or equivalent to both sides of
the cylinder head gasket where the gasket mates with
the timing chain cover, place new cylinder head gas-
ket onto cylinder block.
5. Install cylinder head. Be careful to place head
squarely over guide pins.
Rotate camshaft so that recesses are in vertical posi-
tion to allow installation of left row of bolts.
6. Install 10 head bolts. Tighten the bolts a little at
a time in the sequence shown in Figure 6A-20. Give
bolts a final torque in the same sequence. Torque to
72 lb. ft. (cylinder head cold). Use same procedure
for cylinder head to timing chain cover bolts with
final torque at 17
lb.ft. See Figure 6A-20. These
torques apply to lightly oiled threads.
Figure 6A-20 Cylinder Head Bolt Tightening
sequence7. Slide camshaft sprocket with assembled chain onto
camshaft and guide pin and fasten with bolts. Install
nylon adjusting screw. After sprocket has been at-
tached to camshaft, recheck alignment to see that
chain has not slipped. Close front access hole.
8. Check camshaft end clearance between cover and
nylon screw with feeler gauge. Clearance should be
.004” - .008” Excess clearance can be eliminated by
carefully readjusting cover with a suitable drift.
Reconditioning Valves and Guides1. Remove cylinder head. Place on clean surface.
Place head on bench supported at each end by a
block of wood to prevent damage to valves.
2. Using suitable spring compressor, such as J-8062,
compress valve spring and remove cap retainers. Re-
lease tool and remove spring and cap. See Figure 6A-
21.3. Remove valves. Place valves in numerical order so
that they can be reinstalled in original location.
4. Remove all carbon from combustion chambers,
piston heads, and valves. When using scrapers or

6A- 161973 OPEL SERVICE MANUALInspection of Connecting Rod Bearings and
Crankshaft JournalsRemove oil pan.
After removal of oil pan, disconnect two connecting
rods at a time from crankshaft and inspect the bear-
ings and crankpin journals. While,tuming crankshaft
it is necessary to
t&porarily reconnect the rods to
crankshaft to avoid possibility of damaging the jour-
nals through contact with loose rods.
If connecting rod bearings are chipped or scored they
should be replaced. If bearings
are in good physical
condition check for proper clearance on crankpins as
described under, checking clear$nce and selecting
replacement connecting rod beartngs.
If crankpin journals are scored or ridged, the crank-
shaft must be replaced, or reground for undersize
bearings, to insure satisfactory life of connecting rod
bearings. Slight roughness may be polished out withfine grit polishing cloth thoroughly wetted with en-
gine oil. Burrs may be honed off with a fine oil stone.
Use an outside micrometer to check crankpins for
out- of-round. If crankpins are mpre than
,002” out-
of- round, satisfactory life of new ,bearings cannot be
expected.
Checking Clearance and Selecting Replacement
Connecting Rod BearingsService bearings are furnished in standard size and
several undersizes. The clearance of connecting rod
(and crankshaft) bearings may be checked by use of
Plastigage, Type PG-1 (green), or equivalent, which
is soluble in oil.
1. Remove connecting rod cap with bearing shell.
Wipe off oil from bearing and crankpin journal, also
blow oil out of hole in crankshaft.
2. Place a piece of the plastic-type gauge material
Figure 6A-25 Checking Bearing
Cleatance WithPlastic-Type Gaugelengthwise along the bottom center of the lower bear-
ing shell (Figure 6A-25, view A), then install cap
with shell and tighten nuts to 36 lb. ft. Do not turn
crankshaft with gauge type material in bearing.
3. Remove bearing cap with bearing shell, the flat-
tened piece of gauge will be found adhering to either
the bearing shell or the crankpin. Do not remove it.
4. Using the scale printed on the envelope, measure
the flattened piece of gauge at its widest point. The
number within the graduation which closely corre-
sponds to the width of the gauge, indicates the bear-
ing clearance in thousandths of an inch. See Figure6A-25, View B.
5. The desired clearance with a new bearing is.0006”- .0025”. If bearing has been in service it is
advisable to install a new bearing if the clearance
exceeds .003”, however if bearing is in good condi-
tion and is not being checked because of bearing
noise, it is not necessary to replace the bearing.
6. After the proper size bearing has been selected,
clean off the gauge, oil thoroughly, reinstall cap with
bearing shell and tighten nuts to 36 lb. ft.
CRANKSHAFT BEARINGS AND SEALS
Replacement of Crankshaft BearingsA crankshaft bearing consists of two halves or shells
which are identical and are interchangeable in cap
and crankcase. All crankshaft bearings except the
rear main bearing are identical. The crankshaft end
thrust is taken up the rear (No. 5) main bearing.
Figure 6A-26 Engine Crankshaft Bearings
When the shells are placed in crankcase and bearing
cap, the ends extend slightly beyond the parting
sur-faces so that when cap bolts are tightened the shells
will be clamped tightly in place to insure positive

ENGINE MECHANICAL AND MOUNTS6A- 17
seating and to prevent turning.The ends of she//s
must never be tiled flush with parting surface of
crankcase or bearing cap.Crankshaft bearings are the precision type which do
not require reaming to size. Shims are not provided
for adjustment since worn bearings are readily re-
placed with new bearings of proper size. Bearings for
service replacement are furnished in standard size
and undersizes. Under no circumstances should
crankshaft bearing caps be tiIed to adjust for wear in
old bearing.After removal of oil pan, pipe and screen assembly,
perform the following removal, inspection and in-
stallation operations on each crankshaft bearing in
turn so that the crankshaft will be well supported by
the other bearings.
If crankshaft has been removed to check straightness
the following procedure is suggested. Rest crank-
shaft on “V-blocks” at number one and number live
main bearing journals. Check indicator runout at
No. 3 main bearing journal. Total indicator reading
should not exceed
.C012”.1. Since any service condition which affects the
crankshaft bearings may also affect the connecting
rod bearings, it is advisable to inspect connecting rod
bearings
first. If crankpins are worn to the extent
that crankshaft should be replaced or reground, re-
placement of crankshaft bearings only will not be
satisfactory.
If replacement of cylinder block or crankshaft is re-
quired, always check main bearing clearance with
plastic-type gauge to obtain specified limits.
2. Remove one bearing cap, then clean and inspect
lower bearing shell and the crankshaft journal. If
journal surface is scored or ridged, the crankshaft
must be replaced or reground to insure satisfactory
operation with new bearings. Slight roughness may
be polished out with tine grit polishing cloth
thoroughly wetted with engine oil, and burrs may be
honed off with a tine stone.
3. If condition of lower bearing shell and crankshaft
journal is satisfactory, check the bearing clearance
with a plastic-type gauge.
4. When checking a crankshaft bearing with plastic-
type gauging material, turn crankshaft so that oil
hole is up to avoid dripping of oil on the gauge
material. Place paper shims in lower halves of adja-
cent bearings and tighten cap bolts to take the weight
of crankshaft
off the lower shell of beating being
checked.5. If bearing clearance exceeds
.C03”, it is advisable
to install a new bearing; however, if bearing is in
good condition and is not being checked because ofbearing noise, it is not necessary to replace the bear-
ing.6. Loosen all crankshaft bearing cap bolts
l/2 turn,
and remove cap of bearing to be replaced.
7. Remove upper bearing shell by inserting Bearing
Shell Remover and Installer J-8080 in oil hole in
crankshaft, then slowly turning crankshaft so that
the tool rotates the shell out of place by pushing
against the end without the tang. See Figure
6A-27.When turning crankshaft with rear bearing cap
removed hold oil seal to prevent it from rotating out
of position in crankcase.
8. The crankshaft journal cannot be measured with
an outside micrometer when shaft is in place; how-
ever, when upper bearing shell is removed the jour-
nal may be checked for out-of-round by using a
special crankshaft caliper and inside micrometer.
Figure 6A-27 Removing and Installing Crankshaft
Bearing Upper Shell
The caliper should not be applied to journal in line
with oil hole.
If crankshaft journal is more than
.M)12” out-of-
round, the crankshaft should be replaced since the
full mileage cannot be expected from bearings used
with an excessively out-of-round crankshaft.
9. Before installation of bearing shells make sure that
crankshaft journal and the bearing seats in crankcase
and cap are thoroughly cleaned.
10. Coat inside surface of upper bearing shell with
engine oil and place shell against crankshaft journal
so that tang on shell will engage notch in crankcase
when shell is rotated into place.
11. Rotate bearing shell into place as far as possible
by hand, then insert Installer J-8080 in crankshaft oil
hole and rotate crankshaft to push shell into place.
Bearing shell should move into place with very little

6A- 18 1973 OPEL SERVICE MANUAL
pressure. If heavy pressure is required, shell was not
started squarely and will be distorted if force into place.
12. Place lower bearing shell in bearing cap, then
check clearance
with plastic-type gauge, as previ-
ously described.
13. The desired clearance with a new bearing is
.0009” to .0025”. If this clearance cannot be obtained
with a standard size bearing, insert an undersize
bearing and check again
w&h plastic-type gauge
material.
14. When the proper size bearing has been selected,
clean out all plastic gauge material, oil the lower
shell and reinstall bearing cap. Clean the bolt holes
and lube bolts, then torque cap bolts to 72 lb. ft. The
crankshaft should turn freely at flywheel rim; how-
ever, a very slight drag is permissible if an undersize
bearing is used.
15. If the thrust bearing shell is disturbed or replaced
it is necessary to line up the thrust surfaces of the
bearing shell before the cap bolts are tightened. To
do this, move the crankshaft fore and aft the limit of
its travel several times (last movement fore) with the
thrust bearing cap bolts finger tight.
16. After bearing is installed and tested, loosen all
bearing cap bolts
l/2 turn and continue with other
bearings. When bearings have been installed and
tested, tighten all bearing cap bolts to 72 lb. ft.
17. Replace rear bearing oil seals.
18. Install pipe and screen assembly and oil pan.
Installation of Rear Bearing Oil
Seals (Engine in Vehicle)
1. Remove transmission, bell housing and clutch.
Refer to appropriate section for removal procedures.
Figure 6A-28 Removing Rear Main Oil Seal
2. Remove flywheel.
3. Punch a hole into oil seal and screw in a sheet
metal screw and pull out oil seal. See Figure
6A-28.
4. To insure proper sealing, lubricate seal with a
suitable protective grease and install on taper ring
J-22928. Turn seal to ensure lip of seal is not turned
back. See Figure
6A-27.
OIL SEAL’6A-29
Figure
6A-29 Installing Oil Seal on Tool J-22928
5. Place tapered ring with oil seal on crankshaft
flange and move lip of seal
over rear of crankshaft.
Be careful not to tilt seal.
Figure 6A-30 Installing Rear Main Bearing Oil Seal
6. Drive in oil seal using Tool J-22928-2. See Figure
6A-30.
7. Install flywheel, clutch, bell housing and transmis-
.

ENGINE MECHANICAL AND MOUNTS6A- 19
sion. When replacing flywheel use new bolts and
torque to 43 lb.ft.
PISTON, RINGS AND CONNECTING RODS
Removal and Disassembly of Piston
and Rod Assemblies
1. Drain oil.
2. Remove oil pan. 3. Remove cylinder head.
4. Examine the cylinder bores above the ring travel.
If bores are worn so a ridge exists, remove the ridges
with a ridge reamer to avoid damaging rings or
cracking ring lands in pistons during removal.
5. Mark the cylinder number on all pistons, connect-
ing rods and caps. Starting at the front end of the
crankcase, the cylinders are numbered l-2-3-4,
6. Remove cap and bearing shell from number 1
connecting rod.
7. Push the piston and
rod assembly up and out of
top cylinder. Then reinstall cap and bearing shell on
rod.
0
-J-23436-4
J-23436-2+
J-6047
Figure
6A-3 1 Piston Pin Removal Tool Layout - 1 .S
Engine
8. Remove other rod and piston assemblies in the
same manner.
9. Remove compression rings and oil rings.
10. Remove piston pin in following manner:
a. Position base support J-6047 on hydraulic press.
b. Place tool J-23436-2 in base support with large
diameter bore facing upward. See Figure
6A-31.
c. Position piston and rod assembly on tool
J-
23436-2 making certain the pin is aligned on tool.
d. Position tool J-23436-4 in opposite end of piston
pin and press pin out.
Inspection of Cylinder Bores
Inspect cylinder walls for scoring, roughness, or
ridges which indicate excessive wear. Check cylinder
bores for taper and out-of-round with an accurate
cylinder gage at top, middle and bottom
ofbore, both
parallel and at right angles to the centerline of the
engine. The diameter of the cylinder bores at any
point may be measured with an inside micrometer or
by setting the cylinder gauge dial at “0” and measur-
ing across the gauge contact points with outside mi-
crometer while the gauge is at the same “0” setting.
If a cylinder bore is moderately rough or slightly
scored but is not out-of-round or tapered, it is possi-
ble to repair the bore by honing to accept a standard
service piston. If cylinder bore is very rough or deeply scored, it may be necessary to rebore the cyl-
inder to fit an oversize piston in order to insure satis-
factory results.
If a cylinder bore is tapered
.ooO5” or more, or is
out-of-round
.0005” or more, it is advisable to hone
or rebore for the smallest possible oversize piston and
rings.
Visual Inspection of Pistons, Rings, and Pins
Clean carbon from piston surfaces and under side of
piston heads. Clean carbon from ring grooves with a
suitable tool and remove any gum or varnish from
piston skirts with suitable solvent.
Carefully examine pistons for rough or scored bear-
ing surfaces, cracks in skirt, head cracked or broken
ring lands, and chipping or uneven wear which
would cause rings to seat improperly or have exces-
sive clearance in ring grooves. Damaged or faulty
pistons should be replaced.
Fitting Pistons to Cylinders
The pistons are cam ground, which means that the

ENGINE MECHANICAL AND MOUNTS6A- 21
2.. Expand a telescope gage to fit the cylinder bore at
right angles to the piston pin 2-l/2” from top. See
Figure 6A-33.cylinders, the glazed cylinder walls should be slightly
dulled without increasing the bore diameter by
means of the finest grade honing stones.
TELESCOPE GAUGE1
Figure 6A-33 Checking Cylinder Bores
TELESCOPE/GAUGE
MICROMETER
Figure
6A-34 Measuring Telescope Gage3. Measure the piston to be installed. See Figure6A-32. The piston must be measured at right angles
to the piston pin
2-l/2” below the top of piston. The
piston must be between
.C008” and .0012” smaller
than the cylinder bore.
Both block and piston must be at approximately the
same temperature when measurements are made or
expansion errors will occur. A
dif.ference of 10 de-
grees F between parts is sufficient to produce a varia-
tion of .0005”.
Fitting New Piston RingsWhen new piston rings are installed without reboringNew piston rings must be checked for clearance in
piston grooves and for gap in cylinder bores; how-
ever, the flexible oil rings are not checked for gap.
The cylinder bores and piston grooves must be clean,
dry, and free of carbon and burrs.
To check the end gap of compression rings, place the
ring in the cylinder in which it will be used and
square it in the bore by tapping with the lower end
of a piston. Measure the gap with feeler gages.
Piston ring end gap should be
,014” - ,022” (top) and
,014” - ,022” (2nd) and the oil ring end gap should
be
.015” - ,055”.
If gap is less than specified, file the ends of rings
carefully with a smooth tile to obtain proper gap.
Install piston rings as follows:
1. Upper ring is chrome plated and can be installed
either way up. Number two (2) ring has to be in-
stalled with the marking “top” up. Oil ring can be
installed either way
up. See Figure 6A-35.
1. PISTON
2. NO.
I COMPRESSION RING - INSTALLED
WITH EITHER SIDE UP.
3. NO. 2 COMPRESSION RING - INSTALLED
WITH “TOP” MARKING TOWARDS THE TOP.
4. UPPER AND LOWER STEEL BAND RING
-
INSTALLED WITH EITHER SIDE UP.5. INTERMEDIATED RING
- INSTALLED WITH
EITHER SIDE UP.
6A-35
Figure 6A.35 Arrangement of Piston Rings2. Install piston rings so gaps are positioned as shown
in Figure 6A-36.