6-cylinder Single Vanos
Procedure (E36, E34, E39)
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BMW Vanos Repair
The following information is
provided for reference purposes only and should be used at your own risk
In no event shall Vanos-BMW.com or its members be liable for incidental,
consequential, or special loss or damages of any kind however caused.
Introduction
Vanos is BMWs name for its variable valve timing units.
Vanos units take on various shapes and design according to car year and model
(engine model). The vanos discussed here is BMW part # 11-36-1-748-036 (M50TU, US
S50) and 11-36-1-748-819 (M52, S52). Its a single vanos, meaning only the intake
valve timing is varied. This vanos unit is part of BMW 6-cylinder engines M50TU,
M52, US S50, S52. These engines were incorporated into a wide range of car
models during years 1993-1999. They are found in the 3-series E36 93-97, 5-series
E34 93-95 / E39 96-98, 7-series E38 95-98, Z3 Roadster 2.8 E36 96-98, EU Z3
Coupe 2.8 E36 96-98, US M3 E36 94-99, US Z3 M E36 98-99.
This vanos has been experiencing a failure. It has been
diagnosed that the failure is due to deterioration of the vanos piston seal
O-ring. It has been determined that the O-ring is made from Buna (Buna-N, NBR,
Nitrile). Buna is a very common O-ring material, but is limited in its temperature
and chemical resistance characteristics. Unfortunately it is fairing quite
badly in the vanos/engine environment. The O-ring has been found to harden,
shrink, and have flat surfaces. This deterioration is causing the O-ring to lose
its functional characteristics and thus cause the vanos to fail. BMW has been engaged
regarding this matter, but has elected to not address the issue, No further
development will be done. New (rebuilt) vanos units are being sold with the same
Buna O-ring. BMW does not provide the vanos piston seal/O-ring as a separate
part.
The double vanos shares the same seals design and O-ring failure as the single
vanos.
The piston O-ring lies under and provides support to a piston
Teflon seal ring. Replacing the O-ring requires removing the Teflon seal to
access the O-ring. The Teflon seal can not be practically removed from the
piston seal groove without damaging it. Thus replacing the O-ring necessarily
requires replacing the Teflon seal.
The Buna O-ring can be replaced with an O-ring made from
Viton. Viton (FKM, Fluorocarbon) has similar functional characteristics to
Buna, but has much higher temperature and chemical resistance characteristics.
Its also recommended for the automobile engine environment. The vanos Teflon
(PTFE filled) seal is not a standard part and needs to be semi-custom manufactured.
The single vanos has one piston with one seal/O-ring.
A vanos seal/O-ring repair kit can be acquired through
Vanos-BMW.com, https://www.vanos-bmw.com/.
It includes a vanos replacement OEM Teflon seal and enhanced (Viton) O-ring.
The double vanos utilizes the same Teflon and O-ring material and design as the
single vanos.
Symptoms
Cars experience:
Overall loss of torque and power, particularly in the lower RPM range, < 3k.
Bogging then surging at 3k RPM. Uneven power distribution and RPM transition.
Engine hesitations in the lower RPM range, < 3k. Louder idle and
intermittent idle RPM hiccups. Difficult takeoffs. Loss of power and bogging
when AC on. Increased fuel consumption.
Repairing the vanos seals provides:
Overall increase in torque and power, particularly in the lower RPM range, <
3k. Resolution of bogging then surging at 3k RPM. Smooth even distribution of
power and RPM transition. Resolution of engine hesitations in the lower RPM
range, < 3k. Quiet stable idle. Smooth easy takeoffs. Improved performance
when AC on. Reduced fuel consumption, by ~10%.
In some cases the engine computer will generate the
following fault code:
P1519 (BMW 212, 0xD4): Vanos mechanically stuck (jamming).
Diagnosis
A vanos fault code, as described above, without previous
tampering with the engine timing, is most likely a vanos seals failure
indication.
Otherwise the vanos needs to be removed from the engine for
inspection. Once the vanos cylinder cover is removed, an inspection of the
piston seals fit in the cylinders will show a loose fit and thus a seals
failure. Removal of the seals from the piston will show the inner O-ring has
flat spots and a loss of elasticity.
In general, a diagnosis is not necessary. The vanos Buna
O-ring is deteriorating in 20k miles (32k kilometers). Thus essentially all the
cars with this vanos have a deteriorated seal O-ring and a failing vanos.
Repair Procedure
The following is an E36, E34 & E39 single vanos piston
seals R&R (remove and replace) procedure.
If the valve cover gaskets are over 40k miles (64k
kilometers) old, then its prudent to replace them during this repair. If they
are over 80k miles (128k kilometers) old, then it is a requirement to replace
them during this repair, otherwise they might leak due to being dismounted and
reused. These gaskets have an estimate lifespan of ~60k miles (96k kilometers)
and replacing them during this repair requires no extra effort. The needed parts
and replacement procedure are included as optional.
Repair time: 4 hours mechanic, 6+ hours DIY.
Parts, Tools, and Shop Supplies
Single vanos seals kit (6-cyl) http://www.vanos-bmw.com/products.html, vanos
gasket (11-36-1-740-840) 7.48/each, 2 x vanos oil hose/pipe washer (32-41-1-093-596)
$.25/each
Optional Parts
Valve cover gasket replacement parts:
Valve cover gasket set: M50TU, US S50 engines 93-95 (silver metal cover) (11-12-0-034-107)
$32.89/each, M52, S52 engines 96-99 (black plastic cover) (11-12-0-034-108)
$35.70/each
15 x valve cover bolt grommet (11-12-1-437-395) $1.37/each, oil fill neck
gasket (11-12-7-526-447) 2.29/each
Easily breakable parts: 4 x cover bolt/nut cap (11-12-1-726-089) 3.05/each, 2 x
fan shroud rivet (17-11-1-712-963) $.35/each, E36: 2 x air duct rivet
(51-48-1-915-964) $.49/each, E39: radiator overflow neck (17-11-0-419-132)
$1.67/each
Easily lost parts: 4 x engine cover pad (11-12-1-730-352) $2.35/each
E36 & E39: Small adjustable hose clamp. Needed if radiator overflow hose
OEM clamp not previously replaced with adjustable clamp.
Gasket scraper, putty-knife
Strait pick tool, razor knife, medium nose pliers (small)
24mm combo wrench, 19mm combo wrench, Philips screwdriver (medium) , torx driver
(any small size), 3 flathead screwdrivers (2 medium, 1 small), tack lifter,
needle file, mirror (small), magnet pickup
22mm socket 1/2, 19mm socket 1/2, 3/8 to 1/2 socket adapter
13mm socket 3/8, 10mm deep socket 3/8, 10mm socket 3/8, E-10 torx socket
3/8
8 mm socket 1/4
1/2 ratchet, 3/8 ratchet, 1/4 ratchet, 3/8 long-arm ratchet, 1/2 long-arm
ratchet
3/8 socket extension (short), 1/4 socket extension (short)
Torque wrench (8 Nm [6 ft-lb], 50 Nm [37 ft-lb])
BMW timing tools:
Camshafts lock blocks (11-3-240), sprocket turner (11-5-490), crankshaft lock
pin (11-2-300), camshaft tensioner lock pin (11-3-292) (or small set nail (3d))
E36 & E39 mechanical fan removal tools
32mm combo wrench, BMW water pump pulley holder (11-5-030) $20/each
Handheld sledge hammer (3lb)
E36 fan/shroud removal tools
~6 x 5/16 (8mm) vacuum hose, 2 small clamps
Paper towels, water based cleaner (simple green 1:10), spray lubricant, brake
cleaner, engine oil (synthetic 5W30)
Parts plate, RTV sealant, large cup
Not shown: large pad (quilt), oil pan, 3 small cloth towels
Repair
Car engine must be cold to perform repair procedure.
M50TU and M52 engine specifics will be labeled M50TU: and M52:.
For easy identification, the M50TU engine (93-95) has a silver metal valve cover,
and the M52 engine (96-99) has a black plastic valve cover.
Right and Left denotations are from car front at hood
orientation.
Removal of fan &
shroud
E36 fan & shroud removal
E34 fan & shroud removal
E39 fan & shroud removal
Removal of cabin filter
housing
E39 cabin filter housing removal
Removal of valve cover
Remove engine top covers.
Pry off 2 center caps at each engine cover (flathead).
Unscrew 2 bolts at right cover, and 2 nuts at left cover (10mm socket 3/8 /
3/8 ratchet & extension, magnet pickup).
Remove right engine cover.
Unscrew oil fill cap, remove left engine cover, reinstall oil fill cap.
M50TU:
Remove valve cover vent hose at cover right front corner.
Pry up retaining clip and pull off connector (flathead).
M52:
Remove valve cover vent hose at cover right front corner.
Press in hose connector ring clip at sides and wiggle off connector.
Warning: Do not pull connector off. This can cause sudden release and break
hose. Wiggle connector off.
Disconnect ignition coils electrical harness.
For each coil, pull up on coil connector metal lock and pull off cable
electrical connector.
M50TU:
Remove connector cables from valve cover cable bracket at cover left side.
M52:
Remove coil harness ground wire from valve cover bolt/stud located between
coils 2 & 3 (8mm socket 1/4 / 1/4 ratchet & extension, magnet
pickup).
M52:
Disconnect coil harness rail from valve cover clips.
Pry on each valve cover coil harness rail right side clip and pull out coil
harness rail (flathead).
Pull off complete coil harness and set on left side components.
Remove coils.
M50TU: Coils mount with nuts.
M52: Coils mount with bolts.
Remove 2 mounts at each coil (10mm socket 3/8 / 3/8 ratchet & extension).
M50TU: Maintain coil harness cables in brackets mounted with coils 3,4,5.
Pull up and out all coils.
Note: Maintain coil/cylinder association for reinstallation. This is not
necessary, but is good practice.
Remove coil ground strap(s) (8mm socket 1/4 / 1/4 ratchet & extension).
M50TU: Ground strap at cylinder 6.
M52: Ground straps at cylinders 1 & 6.
Remove 11 valve cover mounting bolts w/ washers & grommets at perimeter of
valve cover (10mm socket 3/8 / 3/8 ratchet & extension, flathead).
Note: Be sure to not miss the left rear corner bolt.
Remove 4 valve cover mounting bolts/studs w/ washers & grommets at center
of valve cover (10mm socket 3/8 / 3/8 ratchet & extension, flathead).
M50TU: Second bolt/stud from front is same as perimeter bolts.
M52: Third bolt/stud from front is same as perimeter bolts.
Remove valve cover from engine head.
Insert blade (putty-knife) between valve cover gasket and engine head at all
front end accessible locations to break gasket bond.
Pull up and remove valve cover. If resistant, insert blade (putty-knife) between
valve cover gasket and engine head at sticking locations.
Note: If valve cover can not be removed, double check valve cover 11 perimeter
bolts and 4 center bolts/studs have been removed. If valve cover is stuck, pull
up on free front end of cover to break gasket bond on remainder of valve cover.
M50TU: Pull up coil harness cables to allow access for cover removal.
M52: Remove cables from valve cover rear bracket/slot. Lift up on rear cables
to allow access for cover removal.
Maintain cover perimeter gasket with cover.
Valve cover perimeter gasket will stick at rear half moon dips due to RTV
sealant. Pull up on gasket to release.
Remove valve cover sparkplug well gaskets.
Note: If gasket is stuck to engine head, attempt inserting blade between gasket
and head from an edge (putty-knife). This facilitates gasket removal without breaking
plasticized brittle gaskets into pieces.
Remove intake camshaft cover.
Pull up to release clips. Remove from engine bay.
Locking engine timing
Turn crankshaft pulley clockwise until cylinder 1 intake and exhaust cams point
to each other at ~45 degree angle (22mm socket 1/2 / 1/2 long-arm ratchet).
Note: Turning crankshaft counter clockwise is acceptable.
Adjust crankshaft pulley to adjust exhaust camshaft for rear camshaft square to
be flush with head surface (22mm socket 1/2 / 1/2 long-arm ratchet).
Inspect TDC (top dead center) timing marks on engine timing cover and
crankshaft harmonic balancer at ~11 oclock position (mirror). Adjust
crankshaft pulley to align TDC timing marks (22mm socket 1/2 / 1/2 long-arm
ratchet).
Note: Angle of view changes alignment position. A tilted view to ~11 oclock
position provides correct alignment view.
Raise front of car and place on jack stands (follow appropriate procedure;
chock both sides of both rear wheels).
Locate crankshaft lock hole plug at engine right rear (front orientation).
Pry out plug by inserting narrow driver into plug eyelet and prying against
engine frame (torx bit driver).
Insert narrow driver into crankshaft lock hole and roughly measure hole depth.
Measurement will provide reference for crankshaft lock pin insertion in next
step.
Insert crankshaft lock pin into crankshaft lock hole.
Pin should insert as far as narrow driver in previous step.
When lock pin is fully inserted crankshaft pulley will be locked in place and
can not be rotated. Check crankshaft pulley is locked (22mm socket 1/2 / 1/2
long-arm ratchet).
Note: Crankshaft pulley will have very slight play (movement) when locked.
If lock pin does not fully insert or crankshaft pulley is not locked, adjust
crankshaft pulley in slight increments and attempt pin insertion (22mm socket
1/2 / 1/2 long-arm ratchet).
If lock pin still does not fully insert, clean lock hole surfaces (needle
file).
If lock pin persists in not inserting, there might be rust and grime at engine case
hole and/or drive plate / flywheel hole.
Insert wide diameter driver into crankshaft lock hole instead of lock pin
(Philips).
Precisely align timing marks on engine timing cover and crankshaft harmonic
balancer.
Lower car from jack stands (follow appropriate procedure).
Remove 3 valve cover studs at rear of engine head (10mm socket 3/8 / 3/8
long-arm ratchet & extension).
E36: No room for socket extension.
Remove excess RTV sealant at top of engine head at half-moon corners.
Place exhaust camshaft lock block (bolt hole on block right) on exhaust
camshaft rear square and engine head.
Note: Lock block might not fit well until camshaft position adjustment in next
step.
Place open wrench (24mm combo wrench) on exhaust camshaft hex at middle of
camshaft.
Adjust camshaft to allow flush seating of camshaft lock block on engine head
(24mm combo wrench).
For final fine tuning, rock wrench back and forth while feeling block by hand.
Place intake camshaft lock block (bolt hole on block left) on intake camshaft
rear square and engine head.
Note: Lock block might not fit well until camshaft position adjustment in next
step.
Place open wrench (24mm combo wrench) on intake camshaft hex at middle of
camshaft.
Adjust camshaft to allow flush seating of camshaft lock block on engine head
(24mm combo wrench).
For final fine tuning, rock wrench back and forth while feeling block by hand.
Install lock blocks bracket and bolts (13mm socket 3/8 / 3/8 ratchet).
Note: Bracket helps maintain lock blocks position and counters block movements.
Removal of vanos
Remove vanos oil hose and bolt (19mm combo wrench).
Note: There are 2 washers, one at each side of hose end contact surfaces.
Discard washers.
Remove engine lift bracket at vanos intake solenoid.
Remove top and bottom bolts (13mm socket 3/8 / 3/8 ratchet & extension).
Remove bracket.
Disconnect vanos intake solenoid electrical cable connector.
Move valve cover vent hose and vanos oil hose to right side of oil filter
canister to facilitate space for access.
Pull up on solenoid cable to follow to electrical connector.
Press in connector spring clip and pull off cable connector.
M50TU:
Remove cable bracket E-clips under vanos.
Pull off E-clips to left side (medium nose pliers).
M50TU:
Remove cable bracket from mounting studs.
Pry off electrical cable from back of cable bracket and remove bracket.
M52:
Remove vacuum pipe 2 bracket mounting nuts (10mm standard & deep socket
3/8 / 3/8 ratchet).
M52:
Pull off vacuum pipe from mounting studs.
Pull vacuum pipe further out and lay down on thermostat and radiator lower
hose.
Note: Side vacuum hoses provide slack needed to pull forward on vacuum pipe.
Remove 2 vanos exhaust sprocket access bolts (19mm socket 1/2 / 1/2 long-arm ratchet).
Insert cloth towel below exhaust sprocket. This will prevent any falling
bolt from dropping into oil sump.
Remove 4 exhaust sprocket mounting bolts (E-10 torx socket 3/8 / 3/8 ratchet
& extension).
Remove any dropped bolt with magnet pickup and not by hand.
Remove cloth towel.
Install camshaft chain tensioner lock pin.
Press down on tensioner and insert pin up to chain.
Note: Lock pin should not be inserted under chain as it can inadvertently
tension chain.
Remove vanos 6 mounting nuts at front lower half of vanos (10mm standard & deep
socket 3/8 / 3/8 ratchet & extension).
M52: 2nd nut from left and 1st nut from right were removed previously when
removing vacuum pipe.
Cover AC belt and lower radiator hose to protect from oil leakage (towels).
Install small bag over vanos oil feed hole to catch leaking oil (vanos seals
product bag).
Remove vanos from engine head.
Mount sprocket turning tool on exhaust sprocket.
Wiggle vanos forward off engine head while simultaneously turning exhaust
sprocket clockwise.
Note: Turning exhaust sprocket clockwise facilitates chain slop allowing intake
sprocket clockwise rotation which in turn allows vanos splined shaft to be
retracted.
Note: Significant oil will drain from vanos oil feed hole.
Take vanos to oil receptacle and attempt to drain oil from vanos (oil pan).
Tilt vanos to facilitate drainage of oil from vanos inner oil relieve spout and
outer oil feed hole.
Lay vanos down on table with inner side facing up.
Remove and discard vanos gasket at engine head.
Replacement of vanos
piston seals
During following seals installation procedure, great care should be taken to not drop and damage vanos components. Perform work over table, so if part is dropped it will fall to table top.
Remove vanos cylinder cover mounting bolts (10mm socket 3/8 / 3/8 ratchet).
Remove cylinder cover with splined shaft and piston from vanos body.
Drain oil from cylinder and cover into oil receptacle (oil pan).
Wipe off oil from vanos components (towels).
For failure diagnosis verification, insert piston in/out of vanos cylinder and
note loose fit.
Inspect vanos cylinder by feel for any marring. Wall should be exceedingly
smooth with no felt irregularities.
Note: Seal sliding wear patterns will be present. Also cylinder wall will not
be as polished at ends of cylinder.
Piston seals removal and installation
Cut cross section of piston Teflon seal in piston groove (razor knife).
Note: Rocking of blade while pressing helps create cutting motion.
Remove cut Teflon seal from piston grove.
Cut cross section of piston O-ring in piston groove (razor knife).
Note: Rocking of blade while pressing helps create cutting motion.
Remove cut O-ring from piston grove.
Note: Deteriorated O-ring will be flattened at top and bottom surfaces, shrunk
in size, and plasticized thus having a loss of elasticity. This is the common
vanos failure mode.
After both piston seal rings are removed, piston groove will be metal.
Wipe clean piston groove (towel).
Install new O-ring (circular brown) in piston groove.
Insert O-ring in piston groove at one end, and stretch other end over piston
and drop into groove (hands/fingers).
Note: O-ring should not be twisted during installation process.
Verify O-ring is not twisted in piston groove. Adjust and center as necessary
(pick tool).
If Teflon seal in cold environment, <65F (18C), soak seal in warm water for 2+
minutes.
Remove and dry Teflon seal just before installation.
Note: Perform following step on ground over large pad while kneeling with knees
on pad. This minimizes risk of dropping piston and damaging its surfaces.
Install new Teflon seal (rectangular black) in piston groove.
Insert Teflon seal in piston groove at one end, and stretch other end over
piston and drop into groove (hands/fingers). Do not over stretch.
Note: Attempt to stretch Teflon seal evenly and take care to not scuff/damage.
Some sliding of seal on piston rim is normal.
Note: Moderate force is needed to stretch Teflon seal.
[pic]
Once stretched and installed, Teflon seal will fit loosely in piston groove.
Piston Teflon seal resizing
Apply coat of assembly lubricant (engine oil) to vanos
cylinder wall. Be sure to include chamfer (rim bevel).
Apply coat of assembly lubricant (engine oil) to vanos piston Teflon seal and adjacent piston surfaces.
Press in on helical gear shaft to fully separate piston from cylinder cover.
Insert piston into cylinder at ~30 degree angle, then rotate piston to insert
into cylinder.
Rotate piston to be flush with cylinder. As piston is rotated, excess seal
protruding from piston groove will be collected and pressed into piston groove.
If seal is binding, reposition piston and attempt again. With each attempt seal
will partially resized. Eventually piston can be fully rotated without binding
seal.
Press in on splined shaft to fully insert and properly position piston in
cylinder.
Verify cylinder cover is fully seated on vanos body.
Allow piston to sit in cylinder for 2 minutes then remove. Teflon seal will be
compressed close to original size.
Reinstall piston in cylinder.
Press in on splined shaft to fully insert and properly position piston in
cylinder.
Rotate cylinder cover to achieve proper mounting holes orientation.
Mount cover 5 bolts (10mm socket 3/8 / 3/8 ratchet).
Fully tighten, 10 Nm (7 ft-lb) (10mm socket 3/8 / 3/8 torque wrench).
Note: Tighten bolts evenly in crisscross pattern.
Double check piston movement in vanos cylinder by inserting and retracting
helical gear shaft. This will take force due to new seal tight fit.
Comparison of new seal piston resistance to movement in cylinder to old seal
piston movement in cylinder verifies old seal failure.
Fully insert vanos splined shaft in vanos.
Cleaning of parts
Note: When cleaning parts, spray cleaning compound on towel
then wipe component with towel. Components can also be placed in a small
container and sprayed with cleaning compound then individually wiped with
towel.
Clean all mounting bolts/studs, nuts, washers, rubber grommets,
ground strap ends (brake cleaner & towels)
Clean vanos matting surfaces; head, valve cover, oil feed (brake
cleaner & towels).
Remove sealant compound on engine head (gasket scraper,
finger nail).
Clean engine head matting surfaces; vanos, vanos studs, valve cover gaskets
(brake cleaner & towels).
Clean coils mounting contact surfaces (at coils) (brake
cleaner & towels).
Remove sealant on valve cover gasket (pick tool, finger
nail).
Clean valve cover gaskets (water based cleaner & towels).
Clean valve cover mating surfaces; gaskets and mounting bolt access holes
(water based cleaner & towels), coils (brake cleaner & towels).
Optional: Replacement of valve
cover gaskets
Replace valve cover gaskets.
Remove 15 valve cover bolt grommets from bolts and install new grommets on
bolts.
Remove valve cover oil fill cap. Remove oil fill neck gasket and install new
gasket. Mount valve cover oil fill cap.
Note: If old gasket is stuck to valve cover, attempt inserting blade between
gasket and cover starting from an edge (putty-knife). This facilitates gasket
removal without breaking plasticized brittle gaskets into pieces.
Installation of vanos
Note: Verify old vanos gasket is removed from engine head and surface clean.
Mount new vanos gasket onto engine head front. Mount top corners onto dowels
and place gasket flush with head surface.
Note: Gasket is asymmetric.
Mount sprocket turning tool onto exhaust sprocket.
Rotate exhaust sprocket clockwise as far as possible. This will rotate intake
sprocket clockwise as far as possible.
Note: This step is critical for proper installation of vanos in next step.
Fully insert vanos splined shaft in vanos. Note: This step is critical for
proper installation of vanos.
Mount vanos onto engine head front.
Insert vanos onto engine head studs. Insert helical gear shaft into intake
sprocket.
Rotate helical gear shaft and slightly insert into sprocket. Helical gear shaft
will slightly insert into sprocket and stop rotating.
Note: This step is critical for proper installation of vanos.
Mount sprocket turning tool onto exhaust sprocket.
Rotate exhaust sprocket counter clockwise while pushing in on vanos to insert
helical spline shaft into intake sprocket. Wiggle vanos and sprocket tool to
help insertion.
Note: It is critical to insert into first possible gear spline alignment.
Push vanos in while turning sprocket.
Insert vanos onto engine head studs, then vanos top corners onto head
matting dowels.
M52: Do not install 2nd nut from left and 1st nut from right in this step. Thus
only 4 nuts will be installed.
M50TU: Install all 6 nuts.
Install vanos mounting nuts and tighten evenly working back and forth (10mm
standard & deep socket 3/8 / 3/8 ratchet & extension).
Fully tighten, 8 Nm (6 ft-lb) (10mm standard & deep socket 3/8 / 3/8
torque wrench & extension).
Remove camshaft chain tensioner lock pin.
Press down on chain tensioner and remove lock pin.
Insert cloth towel below exhaust sprocket. This will prevent any falling
bolt from dropping into oil sump.
Install 4 exhaust sprocket mounting bolts and tighten evenly in crisscross
pattern (E-10 torx socket 3/8 / 3/8 ratchet & extension).
Remove any dropped bolt with magnet pickup and not by hand.
Fully tighten, 20 Nm (15 ft-lb) (E-10 torx socket 3/8 / 3/8 torque wrench
& extension).
Remove cloth towel.
Install 2 vanos exhaust sprocket access bolts (19mm socket 1/2 / 1/2
ratchet).
Fully tighten, 50 Nm (37 ft-lb) (19mm socket 1/2 / 3/8 torque wrench & 3/8
to 1/2 socket adapter).
M50TU:
Install cable bracket under vanos onto electrical cable.
Press cable into bracket rear cable slot.
M50TU:
Install cable bracket onto mounting studs.
Install cable bracket E-clips onto mounting studs (medium nose pliers).
M52:
Install vacuum pipe onto mounting studs.
Install 2 bracket mounting nuts (10mm standard & deep socket 3/8 / 3/8
ratchet).
Fully tighten, 8 Nm (6 ft-lb) (10mm standard & deep socket 3/8 / 3/8
torque wrench).
Verify 6 vanos mounting nuts fully tightened, 8 Nm (6 ft-lb) (10mm standard
& deep socket 3/8 / 3/8 torque wrench).
Install vanos intake solenoid electrical cable connector.
Press in connectors until clip snaps in place.
Install engine lift bracket at vanos intake solenoid.
Install long bolt at top and short bolt at bottom (13mm socket 3/8 / 3/8
ratchet & extension).
M50TU: Install ground wire with top bolt.
Fully tighten, 8 Nm (6 Ft-lb) (13mm socket 3/8 / 3/8 torque wrench &
extension).
Install vanos oil hose with bolt and 2 new washers (19mm combo wrench).
Mount first washer on bolt. Insert bolt through hose. Mount second washer on
bolt. Screw bolt onto vanos.
Fully tighten, 32 Nm (24 ft-lb) (19mm combo wrench / by feel).
Note: Insert rod (flathead) between hose pipe and vanos intake solenoid to keep
hose from turning.
Unlocking engine timing
Remove camshaft locking blocks.
Remove sealant compound on engine head half moon corners (gasket scraper,
finger nail).
Clean engine head matting surface (brake cleaner & towels).
Install 3 valve cover studs at rear of engine head (10mm socket 3/8 / 3/8
ratchet & extension).
Fully tighten, 8 Nm (6 Ft-lb) (10mm socket 3/8 / 3/8 torque wrench &
extension).
E36: No room for socket extension.
Raise front of car and place on jack stands (follow appropriate procedure;
chock both sides of both rear wheels).
Remove crankshaft lock pin from crankshaft lock hole.
Note: Wiggle pin while pulling to help release.
Insert plug into crankshaft lock hole.
Note: If plug difficult to insert, insert narrow driver into plug eyelet and
press in plug (torx bit driver).
Lower car from jack stands (follow appropriate procedure).
Installation of valve cover
Install intake camshaft cover.
Orient cover with arched end at rear and open end at front.
M50TU: Lift coil electrical harness wires to facilitate access.
Press down on cover to lock tabs on valvetrain.
When fully installed, cover will have no vertical movement and slight axial
(fore/aft) play.
M52:
Install valve cover perimeter gasket and sparkplug well gaskets on valve cover.
M50TU:
Install valve cover sparkplug well gaskets on engine head.
Orient gaskets to fit valve cover studs. Gasket cup side orients down.
Place thin coat of RTV sealant at 2 engine vanos/head contact points and head rear
half moon corners.
Allow sealant to solidify for 2 minutes before mounting valve cover.
M50TU:
Install valve cover perimeter gasket onto engine head/vanos. Take care to align
properly before placement.
Lift coil electrical harness wires to facilitate access.
Install valve cover onto engine head/vanos. Take care to align properly before
placement.
M50TU: Lift up coil electrical harness wires to facilitate access.
M52: Lift up rear cables for access. Install rear cables in cover rear
bracket/slot.
Install 11 bolts w/ washers & grommets at cover perimeter, and 4
bolts/studs w/ washers & grommets at cover center (10mm socket 3/8 / 3/8 ratchet
& extension).
M50TU: Center second bolt/stud from front is same as perimeter bolts.
M52: Center third bolt/stud from front is same as perimeter bolts.
Tighten bolts/studs evenly working back and forth, assuring even pressure
distribution on cover. Tighten until bolts/studs bottom out on head.
Fully tighten, 10Nm (7 ft-lb) (10mm socket 3/8 / 3/8 torque wrench &
extension).
Install coil ground strap(s) with mounting nut(s) (8mm socket 1/4 / 1/4
ratchet & extension).
M50TU: Ground strap at cylinder 6.
M52: Ground straps at cylinders 1 & 6.
Note: Ground strap highly bent end mounts on valve cover stud. Cylinder 1 strap
connector orients to top corner, and cylinder 6 strap connector orients to
bottom corner. This facilitates alignment of strap loose ends to coil mounts.
Install coils.
M50TU: Coils mount with nuts.
M52: Coils mount with bolts.
Install each coil into original sparkplug well with 2 mounts (10mm socket 3/8
/ 3/8 ratchet & extension).
Note: Coil boot will not fully insert onto sparkplug during initial mount. This
is normal.
M50TU: Mount coil harness cable brackets with coils 3, 4, 5. Mount ground strap
with coil 6.
M52: Mount ground straps with coils 1 & 6.
Rotate between coil mounts to mount coil evenly.
M50TU: Mount coils 3, 4, 5 evenly together to assure even mounting of coil
harness cable brackets.
Fully tighten, 10Nm (7 ft-lb) (10mm socket 3/8 / 3/8 torque wrench &
extension).
Install ignition coil electrical harness.
M52: Install coil harness rail on valve cover and clip into place.
For each coil, lift up on connector metal lock, press in cable electrical connector,
and push down on connector metal lock.
M50TU: Install coil harness cables in valve cover left side cable bracket.
M52: Install coil harness ground wire on valve cover bolt/stud located between
coils 2 & 3 (8mm socket 1/4 / 1/4 ratchet & extension).
Install valve cover vent hose at cover front right corner. Push hose connector
onto cover neck until it snaps on.
Install engine covers.
Install right side engine cover. Orient cover arches with intake manifold air
tubes at right.
Install cover 2 mount bolts (10mm socket 3/8 / 3/8 ratchet & extension,
magnet pickup).
Unscrew oil fill cap, install left side engine cover, reinstall oil fill cap.
Install cover 2 mount nuts (10mm socket 3/8 / 3/8 ratchet & extension,
magnet pickup).
Clip on 2 bolt/nut cover caps at center of each engine cover.
Align silver lines on cap with cover. Insert clip at an angle and gently press
down on other end (picture).
Note: Caps are dry, brittle, and will break easily.
Installation of cabin
filter housing
E39 cabin filter housing installation
Installation of fan &
shroud
E36 fan & shroud installation
E34 fan & shroud installation
E39 fan & shroud installation
Post repair procedures
Allow RTV sealant to dry a minimum of one hour before
driving car.
On first engine start after repair engine will experience a
couple engine hiccups at idle. This might be related to trapped air in the
vanos.
Check and replenish engine oil.
Drive car, then park car and let engine oil settle.
Remove oil dipstick; wipe dipstick end; fully reinsert dipstick; remove
dipstick again; read oil marking. If oil is low add needed (small) amount of
new oil at oil fill cap at valve cover.
E36 & E39:
Check and replenish coolant fluid.
When car is fully cold (morning), inspect coolant level at side of expansion
tank (reservoir). Coolant should be at mid level. Fill coolant as needed.
Drive car until warm. Slightly open bleed screw at expansion and allow air to
escape (Philips). Close bleed screw when only fluid is escaping.
Repeat fill and bleed procedure as needed to achieve proper coolant level.
~100 miles (160 kilometers) of city driving is needed to
break-in new seals to achieve smoother RPM transition.
2010 Vanos-BMW.com
sales@vanos-bmw.com