1999 BMW 525i spark plugs

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Cylinder Head Removal and Installation
4 If applicable, remove secondary air injection pump:
Disconnect hose at one-way valve
(A).
Remove bolts at support bracket on strut tower (arrows).
Disconnect electrical harness from bottom of secondary
air injection pump.
Remove mounting bracket from strut tower.
4 Remove ignition coils:
* Disconnect ignition coil harness connectors.
Remove coil mounting fasteners.
Remove coils.
* Remove ground straps.
CA UTIOI\C
Note location of all ground wires. Failure to reinstall grounds
can result in permanent damage to engine control module or
ignition system components.
Set coil harness to side of engine compartment
- Remove cylinder head cover mounting fasteners and remove
cylinder head cover.
NOTE-
The cylinder head cover mounting bolt insulators and gas-
ltets should be reinstalled in their original locations. Male
note of their arrangement during removal.
- Remove spark plugs
4 Remove oil baffle cover from above intake camshaft.

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11 3-61
Cylinder Head Removal and installation I
Remove intake manifold fasteners (A).
Carefully lift intake manifold off engine while checking that all
hoses and harnesses have been disconnected.
Left cylinder head, removing, M62 engine
- Remove intake manifold as described earlier
- Remove left side exhaust manifold. See 180 Exhaust Sys-
tem.
- Drain engine coolant, then remove viscous clutch cooling
fan. See
170 Radiator and Cooling System.
WARNING -
Use extreme caution when draining and disposfng of eng~ne
coolant. Coolant is poisonous and lethal to humans andpets.
Pets are attracted to coolant because of its sweet smell and
taste.
Seek med~cal attention immediately if coolant is ingest-
ed.
4 Remove coolant manifold mounting fasteners and carefully
remove manifold.
NOTE-
Engine shown removed from engine bay
4 Remove ignition coil fasteners and coils (noting location of
ground strap).
- Remove spark plugs.

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/Cylinder Head Removal and Installation
- Remainder of installation is reverse of removal, noting the fol-
lowing:
Use new gaskets when mounting intake
manifold. Tighten
nuts finger tight first, then torque to specification in stages
working diagonally from center out.
Be sure to reinstall ignition coil ground straps at cylinders
no.
3 and no. 7. See 120 Ignition System.
Reinstall cooling fan and shroud. See
170 Radiator and
Cooling System.
Refill and bleed cooling system as described in
170 Radi-
ator and Cooling System.
Change engine oil and filter as described in
020 Mainte-
nance.
CA UTIOG
To prevent damaging engine electricalsystems, be sure to in-
stall all ground wires previously removed.
Tightening torques
Camshaft sprocket to camshaft 15
Nm (11 H-lb)
Coolant manifold to cylinder head 10 Nm (7.5 H-lb)
Cylinder head cover nuts 10 Nm (7.5 ft-lb)
Exhaust manifold to head 22 Nm (17 ft-lb)
Engine mounts to subirame 42 Nm (30 ft-lb)
Spark plugs to cylinder head 22 Nm (17 ft-lb)
Right cylinder head, removing, M62 engine
- Remove left side exhaust manifold. See 180 Exhaust Sys-
tem.
- Remove intake manifold. See Intake manifold, removal
and installation,
M62 engine.
- Drain engine coolant. See 170 Radiator and Cooling Sys-
tem.
WARNING-
Use extreme caution when draining and disposing of engine
coolant.
Coolanl is poisonous andlellial lo liumans andpels.
Pets are
altracled to coolant because of 11s sfieet smell and
fasle. Seelc medcal anenfion immed~alely if coolant is ingesl-
. .-
< Remove engine coolant manlold mo~nlng fasreners and
carei~lly remove manifo d.
. I
NOTE
Engine 8s slioivn removed lor clarify

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1 13-82
1 Cylinder Head Removal and Installation
4 Reinstall cylinder head covers to right and left cylinder heads
using new gaskets.
Check for correct seating of half-moon seals
(A) in back of
cylinder head cover.
Use a small amount of Three Bond
1209 8 or equivalent
sealer at corners
(B) of half-moon cutouts.
- Install cylinder head cover fasteners and tighten uniformly in
'I2 turn steps.
Tightening torque Cvlinder head cover fasteners
10 Nm (7.5 It-lb)
- Install exhaust manifolds using new gaskets and fasteners.
See
180 Exhaust System.
- Refill and bleed cooling system as described in 170 Radiator
and Cooling System.
- Change engine oil and filter as described in 020 Mainte.
nance.
CA UTIOW-
To prevent damaging engine electricalsystems, be sure to in-
stall all ground wires previously removed.
Tightening
tOrqUeS
Camshaft sprocket to camshaft 15 Nm (1 1 ft-lb)
Coolant manifold to cylinder head lo Nm (7.5 It-lb)
Cylinder head cover nuts 10 Nm (7.5 ft-lb)
Exhaust manifold to head 22 Nm (17 ft-lb)
Engine mount to subframe 42 Nm (30 ft-lb)
Spark plugs to cylinder head 22 Nm (17 ft-lb)

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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.)

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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.

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.
Cylinder Head and Valvetrain
< Remove cylinder head cover retaining studs (arrows) from
center and rear of cylinder head.
< Remove spark plugs and install BMW special tool 11 3 260
(A) and 11 3 270 (6) to cylinder head. Tighten tool retaining
bolts in spark plug bores. Do not overtighten bolts.
Tightening
torque
BMW special tool 11 3 260 I1 1 3 270 to 23 Nm (17 It-lb)
cylinder head
- Remove intake camshaft bearing cap for cylinder number 1.
CA UTIOG
Intake camshaft bearing cap 1 is centered with adapter
sleeves. To avoid
can~sllaft daniage, it must be removed bs-
fore any other caps.
Turn eccentric shaft on special tool until pressure is applied
to camshaft bearing caps.
- Remove remaining bearing cap mounting nuts
- Slowly release pressure on camshaft bearing caps by turning
eccentric shaft. Remove bearing caps and camshaft. Repeat
procedure on remaining camshaft.
CAUTION-
Camshaft bearing caps must be reinstalled in their original lo-
cations.
NOTE-
The camshaft bearing caps are coded with a letter anda
number. For example,
'XI" is the first exhaust camshaft
bearing cap at the front of the engine, and
"El "is the intalce
camshaft bearing cap at the front of the engine.
0 The camshafts are stamped with a code letter - "E" for the
intake side and 'MA" for the exhaust side.
0 "E is for Einlap, (German for intake) and 'XA"is for Auspuff,
(German for exhaust).

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Cylinder Head and Valvetrain
< Disconnect fuel injector electrical connectors from injectors.
Pry corner of wire lock clip (arrow) on first injector.
* Repeat for all injectors.
Lift wiring ducts off and set aside.
4 Remove right and left side ignition coil mounting nuts (ar-
rows) and coils.
NOTE-
Male note of location for ground straps (arrow A).
- Remove spark plugs.
- Disconnect positive (+)jumper junction from top of lefl cylin-
der head cover.
4 Remove retaining nuts (arrows) and remove oil lines from
left and right cylinder heads.