Downloaded from www.Manualslib.com manuals search engine
I Engine Removal and Installation
WARNING -
Use extreme caution when draining and disposing of engine
coolant. Coolant is poisonous andlethal to humans andpets.
Pets are attracted to coolant because of its sweet smell and
taste. Seek medical attention immediately if coolant is ingest-
---
Working at rear of intake manifold:
Disconnect brake booster vacuum line (A).
Disconnect fuel tank vent line
(6).
Disconnect hoses (C and D) at coolant manifold
- Remove transmission harness support (E).
- Remove oil filter housing assembly from fender:
- Remove oil filter housing mounting fasteners.
Use stiff wire to secure oil filter housing to engine.
NOTE-
Do not disconnect oil lines from filter housing.
4 Disconnect supply and return fuel lines (where applicable) at
or near fuel rail. Plug open fuel lines.
NOTE-
BMW uses three styles of fuel line connections; a slngle use
clamp, a locking fitting that uses special tool
16 7 050 to re-
lease, and a
quiclc release sleeve (arrows) that disconnects
the line when depressed.
WARNING-
Fuel In fuel line is under pressure (approx. 3 - 5 bar or45 -
75 psi) and may be expelled. Do not smoke or worlc near
heaters or other fire hazards. Keep a fire extinguisher
handy. Before disconnecting fuel hoses, wrap a cloth
around fuel hoses to absorb any lealcing fuel. Catch and
dispose of escaped fuel. Plug all open fuel lines.
. Always unscrew the fuel tank cap to release pressure
in the tank before worlcing on the tank or lines.
< Remove air filter housing and mass air flow sensor:
Disconnect mass air flow sensor (A) and
intalte air temper-
ature sensor
(6) electrical harness connectors.
. Remove air filter housing mounting fastener (arrow).
Loosen intake hose clamp (C).
M62 engine: Remove hose at idle air stabilizer.
Remove air filter housing with mass air flow sensor.
Remove intalte hose from throttle body.
Downloaded from www.Manualslib.com manuals search engine
11 0-20
Engine Removal and Installation
Working at right side of transmission bellhousing, disconnect
electrical harness connections (arrows) from starter. Re-
move starter retaining bolts and remove starter from trans-
mission mount.
M62 TU engine: Disconnect electrical harness connector
for right oxygen sensor from retaining clip and remove re-
taining clip from transmission.
- Working underneath engine compartment at left side:
Unclip positive battery cable from oil pan.
. Remove alternator cooling duct.
4 M62 engine: Remove fastener A and plug connector B from
alternator.
- M62 TU engine: Remove electrical harness connectors from
front of water cooled alternator.
- Remove exhaust system and transmission. See 180 Ex-
haust System and 230 Manual Transmission or 240 Auto-
matic Transmission.
- Working at front of engine:
Remove upper and lower hoses from radiator.
D~sconnect expansion tank hose from coolant pump.
- Remove belt-driven cooling fan:
Counterhold fan with special tool
11 5 050.
Turn fan mounting nut (32 mm) clockwise (left hand
threads) to loosen.
Rotate fan clockwise to remove.
Remove cooling fan shroud:
Disconnect electrical connectors from coolant level sensor
(B) and coolant temperature sensor (C).
. Remove expansion rivets (A) from each side of shroud
Remove coolant hose
(D).
Slide fan shroud with expansion tank up. Remove radiator
overflow tube from spout of expansion tank. Remove radi-
ator fan shroud with expansion tank.
Remove radiator. See
170 Radiator and Cooling System.
Downloaded from www.Manualslib.com manuals search engine
--
-- Engine Removal and installation' -
Remove polyribbed A/C compressor belt:
Mark direction of belt travel if belts are to be reused.
Loosen bolts
(A).
Turn adjusting lug (B) clocltwise to release belt tension.
Working beneath car, remove power steering pump and air
conditioner compressor. Suspend from body using stiff wire.
Remove exhaust manifolds. See
180 Exhaust System.
< lnstall engine lifting device (BMW 11 0 000 or equivalent) to
front and rear engine supports and raise engine until it's
weight is supported. Detach engine mounts.
a Watch carefully for hoses and electrical wires that might
snag.
- installation is reverse of removal:
Replace all gaskets, O-rings and seals.
V-8 engine mounts have two sets of mounting holes. E39
cars use front most mounting holes.
* On cars with automatic transmission, use new O-rings at
ATF cooler lines.
Use new alignment sleeves when installing transmission.
Be sure engine drive belts properly engage pulley grooves.
When installing belt, preload tensioner to stop (toward
belt), then tighten tensioner clamping nut.
lnstall front exhaust pipes using new gasltets and copper
paste and new mounting hardware. See
180 Exhaust
System.
Change engine oil and filter. Check all other fluid levels as
described in
020 Maintenance.
Refill and bleed cooling system as described in
170 Radi-
ator and Cooling System.
CAUTION-
Do not interchange knoclc sensor harness connectors. Seri-
ous engine damage may result
Downloaded from www.Manualslib.com manuals search engine
11 3-6
Cylinder Head Removal and Installation
- Disable ignition system by removing DME main relay. See
610 Component Locations for relay location.
WARNING-
. The ignition system produces high voltages that can be fa-
tal. Avoid contact with exposed terminals and use
exfreme
caution when working on a car with the ignition switched on
or the engine running.
Do not touch or disconnect ignition
components while
the engine is running or being cranked by the starter.
Failure to remove the DME main relay or attempting to
disa-
bie the fuel andignition systems by other methods may result
in damaoe to the enoine control module
(ECM).
- - Remove plastic cylinder head cover(s)
,,I . ,. .*,.,,&- - Remove coil grounding straps.
I CAUTION-
I nition system components. I
- Remove coils.
- Remove spark plugs from all cylinders.
NOTE-
Check the spark plugs for oil deposits that may indicate poor
cylinder sealing, then set them aside in order. Used spark
plugs should be reinstalled in the same cylinder from which
they were removed.
4 Install compression gauge in first cylinder spark plug hole,
tight enough to form a good seal.
- With parking brake set, transmission in PARK or NEUTRAL,
and accelerator pedal pressed to floor, crank engine with
starter. Record highest value indicated by gauge.
NOTE-
* The compression gauge reading should increase with
each compression stroke and reach near its maximum
reading in about
4-6 strokes.
All cylinders should reach maximum compression in the
same number of
strolces. If a cylinder needs significantly
more strokes to reach
maximum compression, there is a
problem.
Downloaded from www.Manualslib.com manuals search engine
. .- . --
Lr -- - - - -- Cylinder Head Removal and Installation I -
- Release pressure at compression gauge valve, then remove
gauge from spark plug hole. Repeat test for each cylinder
and compare results with values given in Table a.
Table a. Compression testing specifications
Minimum compression
6-cylinder
10-1 1 bar (142-156 psi)
V-8 12-14 bar (174-203 psi)
Maximum difference between
cylinders (all engines)
0.5 bar (7 psi)
- Compression readings may be interpreted as follows:
Low compression indicates a poorly sealed combustion
chamber.
0 Relatively even pressures that are below specification nor-
mally indicate worn piston rings
andlor cylinder walls.
Erratic values tend to indicate valve leakage.
Dramatic differences between cylinders are often a sign of
a failed head
gasket, burned valve, or broken piston ring.
- If readings are within specifications, reinstall spark plugs and
ignition coils.
NOTE-
Used spark plugs should be reinstalled in the same cylinder
from which they were removed.
Tightening torque Spark plug to cylinder head 25 Nm
(18 ft-lb)
lanition coils to cylinder head 10 Nm (7.5 ft-lb)
- Remainder of installation is reverse of removal. Be sure to re-
install all wires disconnected during test, especially ground
wires at coils and cylinder head cover (where applicable).
Wet compression test
To further help analyze the source of poorcompression,awet
compression test is the next step.
- Repeat compression test, this time squirt a teaspoon of oil
into each cylinder. The oil will temporarily help seal between
piston rings and cylinder wall, practically eliminating leakage
past rings for a short time.
- If this test yields a higher reading than "dry" compression
test, there is probably leakage between piston rings and
cylinder walls, due either to wear or to broken piston rings.
- Little or no change in compression reading indicates other
leakage, probably from valves.
Downloaded from www.Manualslib.com manuals search engine
..
Cylinder Head Removal and Installation 1
< Remove intake throttle valve and ASC throttle assemblies:
Disconnect ASC throttle cable
(A).
- Remove ASC throttle housing mounting fasteners (B).
NOTE-
It is not necessary to disconnect coolant hoses (C) 01
bowden cables (D).
Remove intake throttle housing mounting hardware, pull
throttle housing off
intake manifold, and set aside.
- Working under intake manifold, disconnect the following:
Engine oil dipstick tube support.
Oil separator return line from dipstick tube.
Intake air temperature sensor electrical harness connector
(underside of intake manifold near throttle body).
* Fuel tank vent line and electrical harness at canister vent
valve.
Remove lower intake manifold supports (arrows).
- Disconnect coolant line retaining bracket at cylinder block.
4 Remove manifold mounting hardware (arrows).
- Remove intake manifold from cylinder head while carefully
checking for electrical connections or hoses.
NOTE-
Fuel rail is removed with intake manifold,
CAUTIOI\C
Stuff clean rags into open intake ports to prevent any parts
from falling into
Nie engine intake.
- Drain cooling system (engine block and radiator), then re-
move radiator cooling fan and fan shroud. See
170 Radiator
and Cooling System.
- Disconnect coolant hoses from thermostat housing.
Downloaded from www.Manualslib.com manuals search engine
-
Cylinder Head Removal and Installation c
q Remove secondary air inject~on check valve (arrow).
4 Remove cylinder head top cover:
Remove plastic trim caps (arrows).
Remove engine oil filler cap.
Remove cover hold down fasteners and lift off cover.
4 Remove ignition coils:
Disconnect ignition coil harness connectors.
. Remove coil mounting fasteners.
Remove coils.
Remove ground straps.
NOTE-
Make note of ground wire at mounting studs arrangement
during removal.
- Remove sparlc plugs.
- Remove cylinder head cover mounting fasteners and remove
cylinder head cover.
NOTE-
The cylinder head cover mounting bolt insulators and gas-
lets should be reinstalled in their original locations. Make
note of their arrangement during removal.
Downloaded from www.Manualslib.com manuals search engine
- - , -. I Cylinder Head Removal and lnstallatio~
4 Remove oil baffle cover from above intake camshaft.
4 Unscrew and remove three cylinder head cover studs (ar-
rows)
at rear of cylinder head.
Set engine to approximate top dead center
(TDC) by turning
crankshaft bolt in direction of rotation (clocltwise when
viewed from front of engine) until camshaft lobes for cylinder
1 face each other (dotted lines) and arrows on camshaft
sprocltets face up.
- Set engine to TDC by aligning "OIP mark of vibration damp-
er with boss cast on lower timing chain cover.
< Lock cranltshaft at TDC:
Remove sealing plug from bore on lower left side of engine
block below starter. Secure crankshaft in
TDC position with
BMW special tool 11 2 300.