Page 157 of 1002
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Cylinder Head Removal and Installation I
4 Rotate crankshaft vibration damper to TDC position. Right
head camshaft lobes for number one cylinder should be in
position shown (arrows).
Working at right cylinder head (passengers side) loosen re-
maining
sprocltet fasteners (arrows) on both intake and ex-
haust camshafts approximately
'/? turn.
4 Loosen and remove primary timing chain tensioner (arrow)
from upper timing chain cover on right head.
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. .- --
I Cylinder Head Removal and Installation
- Evaluate cylinder head as described in 116 Cylinder head
and valvetrain.
Left cylinder head, installing, M62 engine
- Clean cylinder head and block sealing surfaces of gasket
debris, making sure no debris drops into coolant or oil pas-
sages.
- Clean cylinder head bolt holes and check condition of
threads.
< Check cylinder head locator sleeves (arrows) for damage.
If the cylinder head has been machined, a special
0.3 mm
thicker gasket should be installed. The thicker gasket is avail-
able through an authorized
BMW dealer and should be
marked accordingly.
- Place new cylinder head gasket over locating sleeve on
block.
The word
"OBEN" or "TOP" (arrow) printed on the gasket,
must face up.
Set lefl side cylinder head in position on cylinder block while
pressing oil separator outward.
CAUJION-
Male sure the crankshaft, which had been rotated approxi-
mately
45" opposite the direction of engine rotation from
TDC, is still in thatposition before installing the cylinder head.
All pistons must be out of
TDCposition to prevent valvelpis-
ton contact.
- Install new cylinder head bolts and washers finger tight. Be
sure not to remove coating from new cylinder head bolts.
4 Tighten cylinder head bolts in correct sequence (1-10) to
stage
1 torque values.
Page 168 of 1002
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11 3-74
Cylinder Head Removal and Installation
4 Work at left side cylinder head loosen three accessible cam- shaft sprocket fasteners (arrows) on both intake and exhaust
camshafts approximately
'I2 turn.
Toprevent valve
topiston contact, counterholdcamshaft with
27 mm open-end wrench whenever loosening or tightening
camshaft sprocket fasteners. If
necessarq! grind outer side of
wrench jaws to prevent damaging cylinder head.
4 Rotate crankshaft one complete rotation to TDC overlap.
Right (passenger's side of engine) side camshaft lobes for
number one cylinder should be in overlap position as shown
(arrows).
4 Working at left cylinder head, loosen remaining sprocket fas-
teners (arrows) on both
intake and exhaust camshafts ap-
proximately
'I2 turn.
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Cvlinder Head Removal and Installation /
Right cylinder head, installing, M62 engine
- Clean cylinder head and block sealing surfaces of gasket de-
bris, making sure no debris drops into coolant or oil passag-
es.
CA UTIOW-
To prevent valve to piston contact when tightening camshaft
sprocket fasteners, counterhold camshaft with
27 mm open-
end wrench. If
necessarq: grind outer side of wrench jaws to
prevent damaging cylinder head.
- Check cylinder head bolt holes and condition of threads. Re-
move debris and liquids from holes.
4 Check cylinder head locator sleeves (arrows) for damage
CAUTION-
lithe cylinder head has been machined, a special 0.3 rnm
(0.01 1 in.) thickergasket should be installed. The thickergas-
ket is available through an authorized BMW dealer and
should be marked
accordinglw
- Place new cylinder head gasket over locating sleeve on
block.
< The word "OBEN" or "TOP (arrow) printed on the gasket.
must face up.
CAUTION-
Male sure the crankshaft, which had been rotated approxi-
mately
45" opposite the direction of engine rotation from
TDC, is
stillin thatposition before installing the cylinder head.
All pistons must be out of
TDCposition to prevent valve/pis-
ton contact
- Install new cylinder head bolts and washers finger tight. Be
sure not to remove coating from bolts.
4 Tighten cylinder head bolts in correct sequence (1 -10) to
stage
1 torque values.
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This group covers cylinder head and valvetrain service and
repair. Some of the repair procedures described here require
that the cylinder head first be removed as described in
113
Cylinder Head Removal and Installation.
NOTE- For timing chain and
VANOS repair information, see 117
Camshaft Timing Chain.
If it is
determined that the cylinder head will require signif-
icant reconditioning work, a remanufactured cylinder head
may be a good alternative. Remanufactured cylinder
heads are available from an authorized
BMW dealer.
The information given in this repair group is organized ac-
cording to engine code. For engine application information,
see
I00 Engine-General.
For specific repair procedures, refer to the appropriate repair
group:
* 020 Maintenance
100 Engine-General
113 Cylinder Head Removal and Installation
117 Camshafi Timing Chain
= 170 Radiator and Coo!ing System
Special Tools
Special BMW tools are required for most cylinder head ser-
vice described in this repair group. Many of these tools are ex-
pensive and only available through an authorized
BMW
dealer. If the special tools are not available, have the cylinder
head removed and disassembled by an authorized BMW
dealer. Be sure to read each procedure thoroughly before
starting a job to determine which special tools and equipment
will be necessary.
Most of the repairs to a cylinder head require precision
rna-
chine work to specific tolerances. This type of work should be
performed by an authorized BMW repairfacility or an ASE
certified machinist.
71 Torque wrench with flex shaft
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11 6-5
I Cylinder Head and valvetrain1
4 Timing chain tensioner bracket (V-8)
(Tool No. BMW
11 7 380)
CYLINDER HEAD
This section provides the specifications and special recondi-
tioning information necessary to repair the cylinder heads
covered by this manual.
The disassembled cylinder head should be inspected for
warpage and cracks. Check the valve guides and valve seats
for wear before machining a warped head. Always decarbon-
ize and clean the head before inspecting it.
Visually inspect the cylinder head for craclts.
If a cracked cyl-
inder head is suspected and no
craclts are detected through
the visual Inspection, have the head further tested for cracks
by an authorized BMW dealer or an ASE certified machinist.
A cracked cylinder head must be replaced.
NOJE-
When disassembling and inspecting the cylinder head, be
sure to
checlc the camshaft carrier bearing surfaces using a
straight edge for
warpage, and check the lifter bores for wear.
A high-quality straight edge can be used to
checlc for
warpage. A warpage of 0.05 mm (0.002 in.) is acceptable
without machining. A warped cylinder head can be machined
provided no more than 0.3
mm (0.012 in.) of material is re-
moved.
If further machining is required, the head should be
replaced. Removing more than this amount will reduce the
size of the combustion chamber and adversely affect engine
performance. A 0.3 mm
thicker head gasket for machined
heads is available from an authorized BMW parts depart-
ment.
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11 6-6
Cylinder Head and Valvetrain
4 Before machining the head to correct for warpage, measure
the total height
(A) (thickness of the cylinder head). Minimum
height specifications are given in Table a. Cylinder head
height.
NOTE-
6 cylinder and V-8 engines share cylinder head height spec-
ifications.
Table a. Cylinder head height
New Minimum height
(A)
140.0 rnrn (5.512 in.) 139.7 rnrn (5.500 in.)
Valves, leak test
To test the valves for leakage, the cylinder head must be dis-
assembled with camshafts and camshaft carriers removed.
With valve assemblies and spark plugs installed, place the
cylinder head on a workbench with the combustion chamber
facing upward. Fill each combustion chamber with a thin non-
flammable liquid. After fifteen minutes, check the level of the
fluid. If the fluid level in any cylinder drops, that cylinder is not
sealing properly.
Camshaft wear
Camshaft wear is usually caused by insufficient lubrication.
Visually inspect camshaft lobes and journals for wear. Cam-
. ~~ shaft wear specifications are given in Table b. Camshaft
wear specifications.
CA UTIOI\C
If the camshaft is being replaced due to cam lobe wear, it is
recommended that the corresponding lifters should also be
replaced to avoid damaging the new camshaft
Table b. Camshaft wear specifications
6 cylinder engines V-8 engines
Axlal play 0.150-0.330 rnrn 0 200-0 360 rnrn - .-
(0.0060-0 013 in.) (0.008 - 0.014 in ) - - Radlal play 0.020-0.054 rnrn 0.040-0.074 rnrn
(0.0008-0.0021 in.) (0.016 - 0.029 in.)
Page 185 of 1002
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11 6-9
Cvlinder Head and valvetrain1
4 Remove ignition coils and spark plugs.
V-8 models: remove mounting nuts (arrows) from wiring har-
ness ducting.
< V-8 models: disconnect fuel injector electrical connectors
from injectors:
Pry one corner of wire
loclc clip (arrow) on first injector.
Repeat for all injectors.
Lift wire ducts off and set aside.
- V-8 models: disconnect battery jump start post terminal from
left cylinder head cover.
- 6-cylinder models: remove oil filler cap and unclip vent con-
nection from cylinder head cover.
- Remove cylinder head cover mounting fasteners and re-
move cylinder head cover(~).
NOTE-
The cylinder head cover mounting bolt insulators and gas-
Icets should be reinstalled in their original locations. Make
note of their arrangement
during removal.