14 Unscrew the two nuts to disconnect the
exhaust system front downpipe from the
manifold (Chapter 4); disconnect the oxygen
sensor wiring, so that it is not strained by the
weight of the exhaust system.
15 Remove the auxiliary drivebelt (see
Chapter 1).
16 Support the weight of the
engine/transmission using a trolley jack, with
a wooden spacer to prevent damage to the
sump.
17 Unscrew the six nuts securing the
engine/transmission right-hand mounting
bracket, then withdraw the bracket. Unbolt
the auxiliary drivebelt’s idler pulley (see
illustration).
18 Unbolt the cylinder head front and rear
support plates (see illustrations).
19 Remove the timing belt and both
camshafts (see Sections 10 and 13); if the
cylinder head is to be dismantled, withdraw
the hydraulic tappets.
20 Remove the timing belt inner shield (see
Section 9).
21 Working in the reverse of the sequence
shown in illustration 14.32C, slacken the ten
cylinder head bolts progressively and by one
turn at a time; a Torx key (TX 55 size) will be
required. Remove each bolt in turn, and
ensure that new replacements are obtained
for reassembly; these bolts are subjected to
severe stresses and so must be renewed,
regardless of their apparent condition,
whenever they are disturbed.
22 Lift the cylinder head away; use
assistance if possible, as it is a heavy
assembly (see illustration). Remove the
gasket, noting the two dowels, and discard it.
Refitting
23 The mating faces of the cylinder head and
cylinder block 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 soft aluminium alloy is
easily damaged. 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. Clean all the pistons in the
same way.
24 Check the mating surfaces of the cylinder
block 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.
25 If warpage of the cylinder head gasket
surface is suspected, use a straight edge to
check it for distortion. Refer to Part B of this
Chapter, Section 7, if necessary.
26 Wipe clean the mating surfaces of the
cylinder head and cylinder block. Check that
the two locating dowels are in position in the
cylinder block, and that all cylinder head bolt
holes are free from oil.
27 Position a new gasket over the dowels on
the cylinder block surface, so that the
“TOP/OBEN” mark is uppermost, and the
tooth (or teeth, according to engine size)
protruding from one edge point to the front of
the vehicle (see illustration).
28 Temporarily refit the crankshaft pulley,
and rotate the crankshaft anti-clockwise so
that No 1 cylinder’s piston is lowered to
approximately 20 mm before TDC, thus
avoiding any risk of valve/piston contact and
damage during reassembly.
29 As the cylinder head is such a heavy and
awkward assembly to refit with manifolds, it is
helpful to make up a pair of guide studs from
two 10 mm (thread size) studs approximately
90 mm long, with a screwdriver slot cut in one
end - two old cylinder head bolts with their
heads cut off would make a good starting
point. Screw these guide studs, screwdriver
slot upwards to permit removal, into the bolt
holes at diagonally-opposite corners of the
cylinder block surface (or into those where
the locating dowels are fitted, as shown);
ensure that approximately 70 mm of stud
protrudes above the gasket.
30 Refit the cylinder head, sliding it down the
guide studs (if used) and locating it on the
dowels (see illustration). Unscrew the guide
studs (if used) when the head is in place.
31 Fit the new cylinder head bolts dry (do not
oil their threads); carefully enter each into its
hole and screw it in, by hand only, until finger-
tight.
32 Working progressively and in the
sequence shown, use first a torque wrench,
2A•18 In-car engine repair procedures
14.17 Unbolt auxiliary drivebelt idler pulley
14 18A Remove cylinder head front . . .
14.18B . . . and rear support plates
14.22 Using an engine hoist to lift off the
cylinder head complete with manifolds
14.27 Ensuring protruding tooth (or teeth)
“A” are at front and marking “B” is
upwards, locate new cylinder head gasket
on dowels “C”
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.