1998 OPEL FRONTERA seat

6A–59
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.

6A–60
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

6A–61
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.

6A–75
ENGINE MECHANICAL
4. Piston and connecting rod assembly (8)
Apply engine oil to the cylinder bores, the
connecting rod bearings and the crankshaft pins.
Check to see that the piston ring end gaps are
correctly positioned.
015RS019
Legend
(1) No.1 Compression Ring
(2) No.2 Compression Ring
(3) Oil Ring Side Rail Upper
(4) Oil Ring Side Rail Lower
(5) Piston Front Mark
Insert the piston/connecting rod assemblies into
each cylinder with the piston ring compressor. The
front marks must be facing the front of the engine.
Match the numbered caps with the numbers on the
connecting rods. Align the punched marks on the
connecting rods and caps.
Apply engine oil to the threads and seating faces of
the nuts.
Tighten the nuts.
Torque: 54 Nꞏm (5.5 Kgꞏm/40 lb ft)
After tightening the cap nuts, check to see that the
crankshaft rotates smoothly.
NOTE: Do not apply engine oil to the bearing back faces.
015RS020
5. Install oil gallery (7) and tighten the bolts in 2 steps, in
the order shown.
1st step: 29 Nꞏm (3.0 Kgꞏm/22 lb ft)
2nd step: 55
65
051RS009
6. Cylinder block side bolts (6)
Tighten all the bolts to the specified torque in the
order shown.
NOTE: Do not apply engine oil to the crank case side
bolts.
Torque: 39 Nꞏm (4.0 Kgꞏm/29 lb ft)

6B–10
ENGINE COOLING
6. Disconnect the reserve tank hose(4) from radiator.
7. Remove bracket(5).
110RW004
8. Lift up and remove the radiator assembly with hose,
taking care not to damage the radiator core with a fan
blade.
9. Remove rubber cushions on both sides at the bottom.
Inspection
Radiator Cap
Measure the valve opening pressure of the pressurizing
valve with a radiator filler cap tester.
Replace the cap if the valve opening pressure is outside
the standard range.
Valve opening pressure kPa (psi) 88.3
117.7
(12.8
17.1)
Cap tester: 5–8840–0277–0
Adapter: 5–8840–2603–0
Check the condition of the vacuum valve in the center of
the valve seat side of the cap. If considerable rust or dirt is
found, or if the valve seat cannot be moved by hand, clean
or replace the cap.Valve opening vacuum kPa (psi) 1.96
4.91
(0.28
0.71)
110RS006
Radiator Core
1. A bent fin may result in reduced ventilation and
overheating may occur. All bent fins must be
straightened. Pay close attention to the base of the fin
when it is being straightened.
2. Remove all dust, bugs and other foreign material.
Flushing the Radiator
Thoroughly wash the inside of the radiator and the engine
coolant passages with cold water and mild detergent.
Remove all signs of scale and rust.
Cooling System Leakage Check
Use a radiator cap tester to force air into the radiator
through the filler neck at the specified pressure of 196 kPa
(28.5 psi) with a cap tester:
Leakage from the radiator
Leakage from the coolant pump
Leakage from the water hoses
Check the rubber hoses for swelling.

6E–60
ENGINE DRIVEABILITY AND EMISSIONS
Electronic Ignition System Diagnosis
If the engine cranks but will not run or immediately stalls,
the Engine Cranks But Will Not Start chart must be used
to determine if the failure is the ignition system or the fuel
system. If DTC P0341, or P0336 is set, the appropriate
diagnostic trouble code chart must be used for diagnosis.
If a misfire is being experienced with no DTC set, refer to
the
Symptoms section for diagnosis.
Fuel Metering System Check
Some failures of the fuel metering system will result in an
“Engine Cranks But Will Not Run” symptom. If this
condition exists, refer to the
Cranks But Will Not Run
chart. This chart will determine if the problem is caused
by the ignition system, the PCM, or the fuel pump
electrical circuit.
Refer to
Fuel System Electrical Test for the fuel system
wiring schematic.
If there is a fuel delivery problem, refer to
Fuel System
Diagnosis
, which diagnoses the fuel injectors, the fuel
pressure regulator, and the fuel pump. If a malfunction
occurs in the fuel metering system, it usually results in
either a rich HO2S signal or a lean HO2S signal. This
condition is indicated by the HO2S voltage, which causes
the PCM to change the fuel calculation (fuel injector pulse
width) based on the HO2S reading. Changes made to the
fuel calculation will be indicated by a change in the long
term fuel trim values which can be monitored with a Tech
2. Ideal long term fuel trim values are around 0%; for a
lean HO2S signal, the PCM will add fuel, resulting in a fuel
trim value above 0%. Some variations in fuel trim values
are normal because all engines are not exactly the same.
If the fuel trim values are greater than +23%, refer to
DTC
P0131, DTC P0151, DTC P0171, and DTC 1171
f o r i t e m s
which can cause a lean HO2S signal.
Idle Air Control (IAC) Valve
The Tech 2 displays the IAC pintle position in counts. A
count of “0” indicates the PCM is commanding the IAC
pintle to be driven all the way into a fully-seated position.
This is usually caused by a large vacuum leak.
The higher the number of counts, the more air is being
commanded to bypass the throttle blade. Refer to IAC
System Check in order to diagnose the IAC system.
Refer to
Rough, Unstable, or Incorrect Idle, Stalling in
Symptoms for other possible causes of idle problems.
Fuel System Pressure Test
A fuel system pressure test is part of several of the
diagnostic charts and symptom checks. To perform this
test, refer to
Fuel Systems Diagnosis.
Fuel Injector Coil Test Procedure and
Fuel Injector Balance Test Procedure
T32003
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart:
2. Relieve the fuel pressure by connecting the
5-8840-0378-0 Fuel Pressure Gauge to the fuel
pressure connection on the fuel rail.
CAUTION: In order to reduce the risk of fire and
personal injury, wrap a shop towel around the fuel
pressure connection. The towel will absorb any fuel
leakage that occurs during the connection of the fuel
pressure gauge. Place the towel in an approved
container when the connection of the fuel pressure
gauge is complete.
Place the fuel pressure gauge bleed hose in an
approved gasoline container.
With the ignition switch “OFF,” open the valve on the
fuel pressure gauge.
3. Record the lowest voltage displayed by the DVM
after the first second of the test. (During the first
second, voltage displayed by the DVM may be
inaccurate due to the initial current surge.)
Injector Specifications:
Resistance Ohms
Voltage Specification at
10
C-35C (50F-95F)
11.8 – 12.65.7 – 6.6
The voltage displayed by the DVM should be within
the specified range.
The voltage displayed by the DVM may increase
throughout the test as the fuel injector windings
warm and the resistance of the fuel injector windings
changes.

6E–89 ENGINE DRIVEABILITY AND EMISSIONS
The valve or valve seat within the fuel pressure
regulator.
The fuel injector(s).
4. Fuel pressure that drops off during acceleration,
cruise, or hard cornering may case a lean condition.
A lean condition can cause a loss of power, surging,
or misfire. A lean condition can be diagnosed using
a Tech II Tech 2. If an extremely lean condition
occurs, the oxygen sensor(s) will stop toggling. The
oxygen sensor output voltage(s) will drop below 500
mV. Also, the fuel injector pulse width will increase.
IMPORTANT:Make sure the fuel system is not
operating in the “Fuel Cut-Off Mode.”
When the engine is at idle, the manifold pressure is
low (high vacuum). This low pressure (high vacuum)
is applied to the fuel pressure regulator diaphragm.
The low pressure (high vacuum) will offset the
pressure being applied to the fuel pressure regulator
diaphragm by the spring inside the fuel pressure
regulator. When this happens, the result is lower fuel
pressure. The fuel pressure at idle will vary slightly as
the barometric pressure changes, but the fuel
pressure at idle should always be less than the fuel
pressure noted in step 2 with the engine “OFF.”
16.Check the spark plug associated with a particular
fuel injector for fouling or saturation in order to
determine if that particular fuel injector is leaking. If
checking the spark plug associated with a particular
fuel injector for fouling or saturation does not
determine that a particular fuel injector is leaking,
use the following procedure:
Remove the fuel rail, but leave the fuel lines and
injectors connected to the fuel rail. Refer to
Fuel Rail
Assembly
in On-Vehicle Service.
Lift the fuel rail just enough to leave the fuel injector
nozzles in the fuel injector ports.
CAUTION: In order to reduce the risk of fire and
personal injury that may result from fuel spraying on
the engine, verify that the fuel rail is positioned over
the fuel injector ports and verify that the fuel injector
retaining clips are intact.
Pressurize the fuel system by connecting a 10 amp
fused jumper between B+ and the fuel pump relay
connector.
Visually and physically inspect the fuel injector
nozzles for leaks.
17.A rich condition may result from the fuel pressure
being above 376 kPa (55 psi). A rich condition may
cause a DTC P0132 or a DTC P0172 to set.
Driveability conditions associated with rich
conditions can include hard starting (followed by
black smoke) and a strong sulfur smell in the
exhaust.20.This test determines if the high fuel pressure is due
to a restricted fuel return line or if the high fuel
pressure is due to a faulty fuel pressure regulator.
21.A lean condition may result from fuel pressure
below 333 kPa (48 psi). A lean condition may
cause a DTC P0131 or a DTC P0171 to set.
Driveability conditions associated with lean
conditions can include hard starting (when the
engine is cold ), hesitation, poor driveability, lack of
power, surging , and misfiring.
22.Restricting the fuel return line causes the fuel
pressure to rise above the regulated fuel pressure.
Command the fuel pump “ON” with Tech 2. The fuel
pressure should rise above 376 kPa (55 psi) as the
fuel return line becomes partially closed.
NOTE: Do not allow the fuel pressure to exceed 414 kPa
( 6 0 p s i ) . F u e l p r e s s u r e i n e x c e s s o f 4 1 4 k P a ( 6 0 p s i ) m a y
damage the fuel pressure regulator.
CAUTION: To reduce the risk of fire and personal
injury:
It is necessary to relieve fuel system pressure
before connecting a fuel pressure gauge. Refer to
Fuel Pressure Relief Procedure, below.
A small amount of fuel may be released when
disconnecting the fuel lines. Cover fuel line
fittings with a shop towel before disconnecting, to
catch any fuel that may leak out. Place the towel in
an approved container when the disconnect is
completed.
Fuel Pressure Relief Procedure
1. Remove the fuel cap.
2. Remove the fuel pump relay from the underhood
relay center.
3. Start the engine and allow it to stall.
4. Crank the engine for an additional 3 seconds.
Fuel Gauge Installation
1. Remove the shoulder fitting cap.
2. Install fuel gauge 5-8840-0378-0 to the fuel feed line
located in front of and above the right side valve train
cover.
3. Reinstall the fuel pump relay.

6E–93 ENGINE DRIVEABILITY AND EMISSIONS
Idle Air Control (IAC) System Check
Circuit Description
The powertrain control module (PCM) controls engine
idle speed with the idle air control (IAC) valve. To increase
idle speed, the PCM retracts the IAC valve pintle away
from its seat, allowing more air to bypass the throttle bore.
To decrease idle speed, it extends the IAC valve pintle
towards its seat, reducing by pass air flow. Tech 2 will
read the PCM commands to the IAC valve in counts.
Higher counts indicate more air bypass (higher idle).
Lower counts indicate less air is allowed to bypass (lower
idle).
Diagnostic Aids
A slow, unstable, or fast idle may be caused by a non-IAC
system problem that cannot be overcome by the IAC
valve. Out of control range IAC Tech 2 counts will be
above 60 if idle is too low, and zero counts if idle is too
high. The following checks should be made to repair a
non-IAC system problem:
Vacuum leak (high idle) – If idle is too high, stop the
engine. Fully extend (low) IAC with the Tech 2. Start
the engine. If idle speed is above 800 RPM, locate and
correct the vacuum leak, including the PCV system.
Check for binding of the throttle blade or linkage.
Lean heated oxygen sensor signal (high air/fuel ratio) –
The idle speed may be too high or too low. Engine
speed may vary up and down, and disconnecting the
IAC valve does not help. Diagnostic trouble codes
P0131, P0151, P0171, or P0174 may be set. Tech 2
oxygen (O2) voltage will be less than 100 mV (0.1 V).
Check for low regulated fuel pressure, water in fuel, or
a restricted injector.
Rich heated oxygen sensor signal (low air/fuel ratio) –
The idle speed will be too low. Tech 2 IAC counts will
usually be above 80. The system is obviously rich and
may exhibit black smoke in the exhaust.
Tech 2 O2 voltage will be fixed at about 750 mV (0.75
V). Check for high fuel pressure, or a leaking or
sticking injector. A silicon-contaminated heated
oxygen sensor will show an O2 voltage slow to
respond on Tech 2.
Throttle body – Remove the IAC valve and inspect the
bore for foreign material.
IAC valve electrical connections – IAC valve
connections should be carefully checked for proper
contact.
PCV valve – An incorrect or faulty PCV valve may
result in an incorrect idle speed. Refer to
Diagnosis,
Rough Idle, Stalling.
If intermittent poor driveability or
idle symptoms are resolved by disconnecting the IAC,
carefully recheck the connections and valve terminal
resistance, or replace the IAC.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
1. The Tech 2 is used to extend and retract the IAC
valve. Valve movement is verified by an engine
speed change. If no change in engine speed
occurs, the valve can be resettled when removed
from the throttle body.
2. This step checks the quality of the IAC movement in
step 1. Between 700 revolutions per minute (RPM)
and about 1500 RPM, the engine speed should
change smoothly with each flash of the tester light
in both extend and retract. If the IAC valve is
retracted beyond the control range (about 1500
RPM), it may take many flashes to extend the IAC
valve before engine speed will begin to drop. This
is normal on certain engines. Fully extending the
IAC may cause engine stall. This may be normal.