Using A Tap To Clean Out The Threads In The Cylinder Block; Check Dowels Are In Position To Locate Cylinder Head Gasket; Ensuring Gasket Is Fitted With Its Oben/Top Marking Uppermost; Tightening Cylinder Head Down Through Its Stages, Using An Angle Gauge - Opel Zafira B MPV 2006 Owners Workshop Manual

10.16 Using a tap to clean out the threads
in the cylinder block
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11 The mating faces of the cylinder head and
cylinder block/crankcase must be perfectly
clean before refitting the head. Use a hard
plastic or wood scraper to remove all traces
of gasket and carbon; also clean the piston
crowns. Take particular care, as the surfaces
are damaged easily. Also, make sure that the
carbon is not allowed to enter the oil and
water passages - this is particularly important
for the lubrication system, as carbon could
block the oil supply to any of the engine's
components. Using adhesive tape and
paper, seal the water, oil and bolt holes in the
cylinder block/crankcase. To prevent carbon
entering the gap between the pistons and
bores, smear a little grease in the gap. After
cleaning each piston, use a small brush to
remove all traces of grease and carbon from
the gap, then wipe away the remainder with
a clean rag. Clean all the pistons in the same
way.
12 Check the mating surfaces of the cylinder
block/crankcase and the cylinder head for
nicks, deep scratches and other damage. If
slight, they may be removed carefully with a
file, but if excessive, machining may be the
only alternative to renewal (see your local
specialist for machining).
13 Ensure that the cylinder head bolt holes
in the crankcase are clean and free of oil.
Syringe or soak up any oil left in the bolt holes.
This is most important in order that the correct
bolt tightening torque can be applied and
to prevent the possibility of the block being
cracked by hydraulic pressure when the bolts
are tightened.
14 The cylinder head bolts must be discarded
and renewed, regardless of their apparent
condition.
15 If warpage of the cylinder head gasket
surface is suspected, use a straight-edge to
check it for distortion. Refer to Part E of this
Chapter if necessary.
16 Using a tap, clean out the thread in the
four bolt holes at the timing chain end of the
cylinder block (see illustration). Wipe clean
the mating surfaces of the cylinder head and
cylinder block/crankcase.
17 Check that the locating dowels are in
2.2 litre petrol engine in-car repair procedures 28•13
10.17a Check the dowels are in position to
locate the cylinder head gasket ...
10.17b •.• ensuring the gasket is fitted
with its OBEN/TOP marking uppermost
10.21 Cylinder head bolt tightening sequence
position then fit the new gasket to the cylinder
block (see illustrations).
18 Ensure the crankshaft is positioned
approx 60° BTDC (this is to prevent any
damage to the valves or pistons when refitting
the cylinder head).
19 With the aid of an assistant, carefully
refit the cylinder head assembly to the block,
aligning it with the locating dowels.
20 Apply a smear of oil to the threads and
the underside of the heads of the new cylinder
head bolts and carefully enter each bolt into
its relevant hole (do not drop them in). Screw
all bolts in, by hand only, until finger-tight.
21 Working progressively and in sequence,
tighten the cylinder head bolts to their Stage 1
torque setting, using a torque wrench and
suitable socket (see illustration).
22 Once all bolts have been tightened to
the Stage 1 torque, working again in the
specified sequence, go around and tighten
all bolts through the specified Stage 2 angle.
It is recommended that an angle-measuring
gauge is used to ensure accuracy (see
illustration). If a gauge is not available, use
white paint to make alignment marks prior
10.22 Tightening the cylinder head down
through its stages, using an angle gauge