engine OPEL FRONTERA 1998 Workshop Manual
Page 1009 of 6000
6A–53
ENGINE MECHANICAL
2. Remove  camshaft  bracket  fixing  bolt  (5),  camshaft
bracket  (6),  then  camshaft  exhaust  (7),  and  intake
side (8).
3. Remove tappet with shim (11).
4. Use  the  5–8840–2446–0  valve  spring  compressor
and  5–8840–2547–0  valve  spring  compressor
adapter  to  remove  the  split  collar  (12),  valve  spring
with upper seat (13) and valve (14).
014RW042
5. Remove spark plug (1).
CAUTION: Do not remove the spark plugs when the
head  and  plugs  are  hot.  Clean  dirt  and  debris  from
spark plug recess areas before removal.
Clean
Cylinder head
Carefully  remove  all  varnish,  soot  and  carbon  from  the
bare  metal.  Do  not  use  a  motorized  wire  brush  on  any
gasket sealing surface.
Inspection and Repair
1. Cylinder head gasket and mating surfaces for leaks,
corrosion  and  blow–by.  If  the  gasket  has  failed,
determine the cause.
– Insufficient torque on head bolts.
– Improper installation
– Loose or warped cylinder head
– Missing dowel pins
– Warped case surface
2. Cylinder  head  for  cracks,  especially  between  valve
seats and in the exhaust ports.3. Cylinder  head  deck  for  corrosion,  sand  particles  in
head and porosity.
CAUTION:
Do not attempt to weld the cylinder head. Replace
it.
Do not reuse cylinder head bolts.
4. Cylinder head deck, common chamber and exhaust
manifold  mating  surfaces  for  flatness.  These
surfaces  may  be  reconditioned  by  milling.  If  the
surfaces are “out of flat” by more than specification,
the surface should be ground to within specifications.
Replace the head if it requires machining beyond the
repairable limit.
Head surface and manifold surface
Standard: 0.05 mm (0.002 in) or less
Warpage limit: 0.2 mm (0.0079 in)
Maximum Repairable limit: 0.2 mm (0.0079 in)
Head height
Standard height : 133.2 mm (5.2441 in)
Warpage limit : 0.2 mm (0.0079 in)
Maximum Repairable limit : 133.0 mm (5.2362 in)
011RW019
5. Water jacket sealing plugs seating surfaces.
Reassembly
1. Install  Spark  plug  and  tighten  all  the  spark  plugs  to
specified torque.
Torque: 18 Nꞏm (1.8 Kgꞏm/13 lb ft)
2. Tighten sub gear setting bolt.
1. Use 5–8840–2443–0 gear spring lever to turn sub
gear to right direction until the M5 bolt aligns with
the hole between camshaft driven gear and sub
gear. 
Page 1010 of 6000
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ENGINE MECHANICAL
2. Tighten the M5 bolt to a suitable torque to prevent
the sub gear from moving .
014RW025
3. Install  camshaft  drive  gear  assembly  and  tighten
three bolts to the specified torque.
Torque: 10 Nꞏm (1.0 Kgꞏm/89 lb in)
4. Install  camshaft  assembly  and  camshaft  brackets,
tighten twenty bolts on one side bank to the specified
torque.
1. Apply engine oil to camshaft journal and bearing
surface of camshaft bracket.
2. Align timing mark on intake camshaft (one dot for
right  bank,  two  dots  for  left  bank)  and  exhaust
camshaft (one dot for right bank, two dots for left
bank) to timing mark on camshaft drive gear (one
dot).
014RW020
Legend
(1) Intake Camshaft Timing Gear for Right Bank
(2) Intake Camshaft Timing Gear for Left Bank
(3) Exhaust Camshaft Timing Gear
(4) Discrimination Mark
LI: Left Bank Intake
RI: Right Bank Intake
LE: Left Bank Exhaust
RE: Right Bank Exhaust
014RW023
Legend
(1) Right Bank Camshaft Drive Gear
(2) Left Bank Camshaft Drive Gear
(3) Timing Mark on Drive Gear
(4) Dowel Pin 
Page 1011 of 6000
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ENGINE MECHANICAL
014RW024
Legend
(1) Right Bank
(2) Left Bank(3) Alignment Mark on Camshaft Drive Gear
(4) Alignment Mark on Camshaft
(5) Alignment Mark on Retainer
3. Tighten  twenty  bolts  in  numerical  order  on  one
side bank as shown in the illustration.
Torque: 10 Nꞏm (1.0 Kgꞏm/89 lb in)
014RW031
5. Tighten bolt for camshaft drive gear assembly pulley
to the specified torque.
Torque: 98 Nꞏm (10.0 Kgꞏm/72 lb ft) 
Page 1012 of 6000
6A–56
ENGINE MECHANICAL
Valve Spring, Oil Controller, Valve, Valve Guide
Valve Spring, Oil Controller, Valve, Valve Guide and Associated Parts
014RW039
Legend
(1) Camshaft Bracket Fixing Bolts
(2) Camshaft Assembly Inlet
(3) Camshaft Assembly Exhaust
(4) Shim
(5) Tappet
(6) Split Collar(7) Spring Upper Seat
(8) Valve Spring
(9) Oil Controller
(10) Spring Lower Seat
(11) Valve Guide
(12) Valve
Disassembly
1. Remove camshaft bracket fixing bolts (1).
2. Remove camshaft assembly (intake).3. Remove camshaft assembly (Exhaust side).
4. Remove shim (4) and tappet (5). 
Page 1013 of 6000
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ENGINE MECHANICAL
5. Use  5–8840–2446–0  valve  spring  compressor  and
5–8840–2547–0 valve spring compressor adapter to
remove split collar.
014RW042
6. Remove valve spring.
7. Remove valve.
8. Remove oil controller and spring lower seat.
9. Remove  the  valve  guide  using  the  5–8840–2442–0
valve guide replacer.
Inspection and Repair
Valve Spring
CAUTION: Visually  inspect  the  valve  springs  and
replace them if damage or abnormal wear is evident.
1. Measure the free height of the springs. The springs
must  be  replaced  if  the  free  height  is  below  the
specified limit.
Standard : 44.6 mm (1.7559 in)
Limit : 43.6 mm (1.7165 in)
014RS004
2. Measure  the  valve  spring  squareness  with  a  steel
square and replace the valve springs if the measured
value exceeds the specified limit.
Limit : 2 mm (0.0787 in)
014RS005
3. Using a spring tester to compress the springs to the
installed  height,  measure  the  compressed  spring
tension,  and  replace  the  springs  if  the  measured
tension is below the specified limit.
At installed height: 35.0 mm (1.38 in)
Standard: 196 N (44 lb)
Limit: Less than 181 N (41 lb)
014RS006
Valve Guide
CAUTION: Take  care  not  to  damage  the  valve  seat
contact surface, when removing carbon adhering to
the  valve head.  Carefully  inspect  the valve stem for
scratchs  or  abnormal  wear.  If  these  conditions  are
present,  the  valve  and  the  valve  guide  must  be
replaced as a set. 
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ENGINE MECHANICAL
1. Measure the valve stem diameter with a micrometer.
If the valve stem diameter is less than the specified
limit, the valve and the valve guide must be replaced
as a set.
Diameter of Valve Stem
Intake
Standard : 5.977 mm–5.959 mm
(0.2353 in–0.2346 in)
Limit : 5.90 mm (0.2323 in)
Exhaust
Standard : 5.952 mm–5.970 mm
(0.2343 in–0.2350 in)
Limit : 5.90 mm (0.2323 in)
014RS007
2. Measure the inside diameter of the valve guide with a
micrometer. Subtract the measured outer diameter of
the valve stem from the measured inner diameter of
the  valve  guide.  If  the  value  exceeds  the  specified
limit, the valve and the valve guide must be replaced
as a set.
Inside Diameter of the Vale Guide
Inlet clearance
Standard : 0.023 mm–0.056 mm
(0.0009 in–0.0002 in)
Limit : 0.20 mm (0.00787 in)
Exhaust clearance
Standard : 0.030 mm–0.063 mm
(0.0012 in–0.0025 in)
Limit : 0.20 mm (0.00787 in)
Valve Guide Replacement
1. Using  Valve  guide  replacer:  5–8840–2442–0,  drive
out  the  valve  guide  from  the  combustion  chamber
side.
014RS008
2. Apply  engine  oil  to  the  outside  of  the  valve  guide.
Using valve guide replacer 5–8840–2442–0, drive in
a new valve guide from the camshaft side, and check
the valve guide height.
Valve guide upper end height: 13.0 mm (0.5118
in)
(Measured from the cylinder head upper face)
014RW046
3. Check the clearance. If the clearance is less than the
specified  value,  ream  the  inside  diameter  of  valve
guide.  Using  a  sharp  6  mm  reamer,  ream  the  valve
guide to obtain the specified clearance.
Va l v e   S e a t
1. Measure the protrusion of the valve stem when a new
valve is installed in the cylinder head. If the protrusion
of the valve stem exceeds the limit, replace the valve
seat insert or the cylinder head assembly.
Protrusion of valve stem
Intake
Standard: 39.32 mm (1.5480 in) 
Page 1015 of 6000
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ENGINE MECHANICAL
Limit: 39.47 mm (1.5539 in)
Exhaust
Standard: 39.30 mm (1.5472 in)
Limit: 39.45 mm (1.5531 in)
014RW047
2. Measure  the  valve  seat  contact  width.  Make  the
necessary  corrections  if  the  seat  contact  surface  is
damaged  or  rough  or  if  the  contact  width  wear
exceeds the limit.
Valve seat contact width
Standard: 1.1 mm (0.0433 in)
Limit: 1.7 mm (0.0669 in)
014RS011
Contact Surface Angle on Valve Seat on
Va l v e
1. Measure contact surface angle on valve seat.2. If  the  measured  value  exceeds  the  limit,  replace
valve, valve guide and valve seat as a set.
Valve contact surface angle: 45
014RS012
Valve Seat Insert Correction
1. Remove  the  carbon  from  the  valve  seat  insert
surface.
2. Use  a  valve  cutter  to  minimize  scratches  and  other
rough areas. This will bring the contact width back to
the standard value. Remove only the scratches and
rough areas. Do not cut away too much. Take care not
to  cut  away  unblemished  areas  of  the  valve  seat
surface.
Valve seat angle degree: 90
014RW059
3. Apply  abrasive  compound  to  the  valve  seat  insert
surface.
4. Insert the valve into the valve guide.
5.Turn the valve while lapping it to fit the valve seat
insert. 
Page 1016 of 6000
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ENGINE MECHANICAL
6. Check that the valve contact width is correct.
7. Check that the valve seat insert surface is in contact
with the entire circumference of the valve.
014RS014
Valve Seat Insert Replacement
1. Arc weld the rod at several points. Be careful not to
damage the aluminum section.
2. Allow the rod to cool for a few minutes. This will cause
the valve seat to shrink.
3. Strike the rod and pull it out.
014RS015
4. Carefully clean the valve seat press–fit section on the
cylinder head side.
5. Heat the press–fit section with steam or some other
means to cause expansion. Cool the valve seat with
dry ice or some other means.
6. Insert  the  press–fit  section  into  the  valve  seat
horizontally.
Standard fitting interference: 0.14 mm–0.09 mm
(0.0055 in–0.0035 in)7. After insertion, use a seat grinder to grind finish the
seating  face.  Carefully  note  the  seating  angle,  the
contact width, and the depression.
8. Lap the valve and the seat.
Reassembly
1. Install valve guide (1) to cylinder head. Apply engine
oil to the outside of the valve guide. Using valve guide
replacer 5–8840–2442–0, drive in a new valve guide
from the camshaft side.
2. Install  oil  controller  (3)  and  spring  lower  seat  (2).
Using oil controller replacer 5–8840–0623–0, drive in
a new oil controller.
014RW058
3. Install valve to valve guide. Before install valve guide
apply engine oil to the outside of the valve stem.
4. Install valve spring to cylinder head. Attach the valve
spring to the lower spring seat. The painted area of
the valve spring should be facing downward.
014RS020 
Page 1017 of 6000
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ENGINE MECHANICAL
5. Install lower valve spring seat, valve spring and upper
valve  spring  seat  then  put  split collars  on  the  upper
spring  seat,  using  the  5–8840–2446–0  valve  spring
compressor  and  5–8840–2547–0  valve  spring
compressor adapter to install the split collars.
014RW042
6. Install tappet with shim.
7. Install camshaft assembly.
Refer to installation procedure for Camshaft in this
manual.
Valve Clearance Adjustments
NOTE: To adjust valve clearance, apply engine oil to the
cam as well as to the adjusting shim (2) with the cylinder
head  built  on  the  cylinder  block,  give  a  few  turns  to  the
camshaft by means of timing pulley tightening bolt, and
measure  valve  clearance  when  the  nose  of  cam  is  just
opposite to maximum cam lift (1) as shown in illistration
below.
014RW081
Legend
(1) Cam
(2) Shim
(3) Tappet
Valve Clearance Standard Value (cold)
Intake: 0.23 mm–0.33 mm
(0.0091 in–0.0130 in)
Exhaust: 0.25 mm–0.35 mm
(0.0098 in–0.0138 in)
Selection of Adjusting Shim
Shim  to  be  selected  =  (Thickness  of  removed  shim)  +
(Valve clearance measurement – Standard valve)
Based on the above formula, the best suited shim should
be  selected  from  41  sorts  of  shim  (differently  thick  at
0.02mm  (0.0008  in)  intervals  from  2.40mm  (0.0945  in)
through  3.2mm  (0.1260  in)  thick).  Install  the  shim  and
check valve clearance. 
Page 1018 of 6000
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ENGINE MECHANICAL
Replacement of Shim
Let  the  cam  push  down  the  edge  of  tappet  by  using
5–8840–2444–0 valve clearance adjusting tool and push
out  the  shim  with  a  flat  blade  screw  driver  as  shown  in
illustrations below.
014RW082
014RW083
014RW084