NOTE: It is recommended that the timing chain guides, rails and tensioner, be replaced at
the same time as the chain.
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| Disconnect negative cable from battery. |
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| Hold water pump pulley (green arrow) with BMW special tool 11 5 030, or
with a large set of "water pump" pliers. |
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| Remove fan (yellow arrow above) with BMW special tool 11 5
040 or similar slim 32mm wrench. |
| An alternative to using pliers is to install the wrench and
strike wrench sharply with a hammer in a clockwise direction. |
CAUTION: Left hand thread, turn wrench as if to
tighten a regular bolt, to remove the fan.
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| Drain coolant from cylinder block drain plug on right side of block,
behind exhaust manifold. |
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| Drain coolant from radiator, drain plug is in center or on lower left
corner. |
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| Disconnect Air Flow Meter (blue arrow) and loosen intake boot clamp
(yellow arrow). Loosen both 10mm nuts (green arrows) and lift out air box assembly. |
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| Loosen the four 10mm bolts retaining the water pump pulley. Do not remove
yet. |
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| Remove belt by loosening alternator. Hold 19mm adjuster head (red arrow)
with a wrench while loosening 13mm nut behind it (green arrow), to prevent damage to the
adjuster. Loosen top bolt (blue arrow) and nut securing adjusting arm (yellow arrow). Rotate
19mm adjusting nut to bring alternator in towards engine until belt can be removed from
water pump pulley. Water pump pulley is not as deep as alternator pulley, so belt is
easier to remove and install from the water pump pulley. |
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Remove the upper bolt (blue arrow). Swing the alternator away
from the engine to give access to the water hose behind it.
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Remove pulley from water pump.
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| Loosen the three 8mm bolts securing the distributor cap. The bolts are
captive, they do not need to come out of the cap. |
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| Remove the three 3mm Allen screws securing rotor. The screws are captive,
they do not need to come out of the rotor. |
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| Remove rotor adapter from exhaust camshaft. |
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| Remove the distributor housing from the right side of the cam box |
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| Remove the cover from the left side of the cam box. |
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| Remove coolant hose from water pump. |
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| Remove bypass hose from back of water pump. |
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| Remove the three 13mm (green and blue arrows) and four 10mm bolts (yellow
arrows) securing the water pump to the upper timing cover. |
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| Remove nuts holding spark plug harness to valve cover, remove spark plug
boots and place harness aside. |
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| Loosen clamp and remove purge hose. |
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| Remove the eighteen 10mm nuts securing the valve cover and remove it from
engine. |
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| Remove remaining accessory belts the same way the alternator
belt was removed, loosening pivot points and the tensioner, then rotating the 19mm
tensioner nut. A/C belt can be tight. If so, remove by placing a screwdriver between belt
and pulley and rotating engine by hand. |
DANGER: Keep fingers away from belts if rotating
belts. Serious injury can occur.
|
| Remove the two 13mm bolts securing alternator bracket to front of engine,
and the 17mm bolt securing the bracket to the side of the cylinder block (not pictured). |
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| Remove bolts from power steering pump and place to the side,
do not disconnect the hoses. |
| Remove reinforcement plate from rear of oil pan, at transmission. |
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| Lock flywheel with BMW special tool 11 2 100 or a large
screwdriver. |
| Remove nut from the crank pulley. |
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| Rotate engine to TDC. Look for mark on pulley. |
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| Take note of camshaft location, there are marks on the rear of the front
caps, and on the cams. |
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| Slide pulley off evenly. Pulley fit is a very tight
tolerance, it must be removed evenly or will jam. If you pry it, do so from opposite sides
at the same time, this will keep it even. |
| Drain engine oil |
Remove the eighteen 10mm lower oil pan bolts and remove
pan. |
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| Remove the three 10mm bolts connecting upper oil pan and lower timing
cover. |
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| Loosen the rest of the upper oil pan bolts. |
| Remove the timing chain tensioner plug from the right side of the
cylinder head. Place a rag on the A/C compressor to catch the oil that will be released
when the tensioner plug is removed. |
 |
CAUTION: Plug is under considerable spring tension !
|
| Remove tensioner spring and piston. |
| Remove the 2 bolts joining the cylinder head and lower timing cover. |
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| Remove the remaining bolts retaining the lower cover to the
cylinder block. |
| Free the oil pan gasket from the lower timing cover with a
knife or razor blade. |
| If gasket is damaged, remove upper oil
pan and replace gasket. |
| Remove lower timing cover. |
| Remove upper chain guide. |
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| Open lock plates and unscrew timing chain gears. Remove both gears. |
 |
CAUTION: Never turn crankshaft with timing chain loose or removed.
|
| Remove the two circlips on the timing chain guide. Pull guide rail
forward and swing lower end to the left. Once upper end is clear of cylinder head, slide
rail off upper mount. |
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| Remove chain. |
|
Changing upper tensioner rail:
|
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| Partially unscrew bolt on right front of cam carrier, so that it no
longer covers the pivot shaft for the upper tensioner rail. |
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| Install BMW special tools 11 3 04 , 11 3 042 and 11 3 062. Or a slide
hammer or puller and remove the shaft. Alternatively, you can thread an 8x1.25 bolt into
the shaft and pull while rotating the shaft. |
 |
| Lift upper tensioner rail out of cylinder head. |
|
Changing lower tensioner rail:
|
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| Remove circlip from pivot, move top of rail to the left and slide off
pivot. (White chain guide and timing chain MUST be removed before tensioner rail can be
removed.) |
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Installation:
|
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| Chain must be in channel of guide before installing guide. |
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| Chain goes on inside of gear in head. |
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| If necessary, replace gears. |
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| Install piston with groove on slotted end facing up, and groove on other
end facing the exhaust manifold. |
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| Prime the tensioner by pouring oil down inside of timing
chain area after installation of front cover. Pump tensioner rail back against tensioner,
with a long screwdriver, until resistance becomes quite high. |
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