Opel Frontera UBS. Manual - part 1267

ENGINE MECHANICAL 6A – 1

SECTION 6A

ENGINE MECHANICAL

CONTENTS

PAGE

Cylinder Head ..................................................................................................................

6A-  2

Valve Springs, Valve Stem Oil Seal, Valve, Valve Guide, Push rod ...........................

6A-  7

Camshaft, Tappet ............................................................................................................

6A-14

Rocker Arm Assembly ....................................................................................................

6A-19

Oil pump ..........................................................................................................................

6A-21

Crankshaft ........................................................................................................................

6A-25

Piston and Connecting Rod ............................................................................................

6A-34

Cylinder Block ..................................................................................................................

6A-42

SECTION

6A – 2 ENGINE MECHANICAL

CYLINDER HEAD

NOTE:

•

During disassembly, be sure that the valve train
components are kept together and identified so that
they can be re-installed in their original locations.

•

Before removing the cylinder head from the engine
and before disassembling the valve mechanism, make
a compression test and note the results.

DISASSEMBLY

1.

Thermostat Housing Assembly

2.

Injection Nozzle Holder

3.

Glow Plug and Glow Plug Connector

4.

Rocker Arm Shaft and Rocker Arm

5.

Push Rod

6.

Cylinder Head

•

Refer to Section 6A2 “Cylinder Head”

CLEAN

•

Cylinder head bolts

•

Cylinder head
Carefully remove all varnish, soot and carbon to the
bare metal.  Do not use a motorized wire brush on any
gasket sealing surface.

ENGINE MECHANICAL 6A – 3

INSPECTION AND REPAIR

Make the necessary adjustments, repairs, and part re-
placements if excessive wear or damage is discovered
during inspection.

•

Cylinder head gasket and mating surfaces for leaks,
corrosion and blow-by.  If the gasket has failed,
determine the cause;
– Improper installation

Loose or warped cylinder head

– Insufficient torque on head bolts
– Warped case surface

1.

Cylinder head bolts for damaged threads or stretch-
ing and damaged heads caused by improper use of
tools.

CAUTION:

Suspected bolts must be replaced.

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.

4.

Cylinder head deck, intake and exhaust manifold
mating surfaces for flatness.

These surfaces may be re-conditioned by milling.  If
the surfaces are “out of flat” by more than specifica-
tion, the surface should be grinded to within specifi-
cations.  If more than limit of specification, it should
be replaced.

5.

Water jacket sealing plugs seating surfaces.

6.

Use a straight edge and a feeler gauge to measure
the manifold cylinder head fifting face warpage.
Regrind the exhaust manifold cylinder head fifting
surfaces if the measured values are between the
specified limit and the standard.
If the measured values exceed the specified limit, the
manifold must be replaced.

Cylinder Head
Lower Face
Warpage

mm (in)

0.05 (0.0020)
or less

0.20 (0.0079)

Cylinder Head
Height

92 (3.6220)

–

Standard

Limit

Standard

Limit

mm(in)

0.05 (0.0020) or less

0.20 (0.0079)

Exhaust Manifold Warpage

6A – 4 ENGINE MECHANICAL

Hot plug depression

1.

Clean the cylinder head lower side, taking care not to
damage the hot plug surfaces.

2.

Use a straight edge and feeler gauge to measure hot
plug depression in a straight line from the No.1 hot
plug to the No.4 hot plug.

If the measured value exceeds the limit, the hot plugs
must be replaced.

Hot plug removal

1.

Insert a 3.0 – 5.0 (0.12 – 0.20 in.) diameter bar into the
nozzle holder fitting hole unit it makes contact with
the hot plug.

2.

Lightly tap the bar with a hammer to drive the hot
plug free.

If the measured value exceeds the limit, the hot plugs
must be replaced.

mm(in)

0.02 (0.0008)

Depression Limit

Combustion chamber inspection

1.

Remove the carbon adhering to the inside of the
combustion chamber.  Take care not to damage the
hot plug fitting positions.

2.

Inspect the inside of the combustion chamber, the hot
plug hole, and the hot plug machined faces for
cracking and other damage.
If cracking or damage is present, the cylinder head
must be replaced.

Note:

Be absolutely certain that there are no scratches or
protuberance on the combustion chamber surfaces which
will be in contact with the hot plug after it is installed.
There flaws will prevent the hot plug from seating
correctly.

Hot plug inspection

Inspection the hot plugs for excessive wear and other
damage.  Replace the hot plugs if either of these condi-
tions are discovered.

Hot plug installation

1.

Align the hot plug knock ball ➀ with the cylinder head
groove ➁ and tap it temporarily into position with a
plastic hammer.