| Hold water pump pulley (green arrow) with BMW special tool 11
5 030, or with a large set of "water pump" pliers. |
 |
| 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.
|
| Remove distributor cap by loosening the 8mm bolts that are
securing it. Some cars may have a cover that is secured by 3mm Allen bolts, remove cover,
then cap. |
 |
| Remove nuts holding spark plug harness to valve cover, remove
spark plug boots and place harness aside. |
 |
| Remove distributor rotor by loosening the three 3mm Allen
bolts. As with cap, bolts are captive and do not have to be fully removed to remove the
component. |
 |
| Remove 6mm Allen bolt from DME adapter and pull adapter from
end of camshaft. |
 |
| Remove distributor housing from right side of cam box. |
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| Remove cover from left side of cam box. |
 |
| Loosen clamp and remove purge hose at left rear of valve
cover. |
 |
| Remove the eighteen 10mm nuts securing valve cover and lift
off engine. |
 |
| Remove the end cover at rear of head. (six 10mm bolts) |
 |
| Rotate crankshaft until cylinder number 1 is on TDC. Take note of
camshaft location, there are marks on the rear of the front caps, and on the cams. |
 |
 |
| Remove upper timing chain guide rail. |
 |
| Remove the timing chain tensioner plug from the right side of
the cylinder head |
 |
CAUTION: Plug is under considerable spring tension !
|
| Remove timing chain tensioner spring and piston. |
|
| Open lock plates and unbolt timing chain gears, remove gears. |
 |
CAUTION: Never turn crankshaft with timing chain loose or removed.
|
| Loosen the cam bearing caps very gradually, take your time, it
costs less than a new camshaft. |
 |
| Mark camshafts as intake and exhaust and remove from cylinder
head. Standard camshafts are identical, but should be installed in the same position they
are removed from. |
|
Installation:
|
| Check camshafts for wear. Lobe height specification is
43.713mm (1.721") |
|
| Place camshafts in TDC #1, install caps in correct order, they
are numbered A 1 through 5 for exhaust and E 1 through 5 for intake, and tighten
caps very gradually. Final torque for caps is 22 Nm (16 ft lbs.) (A and E are
initials for the German words for intake and exhaust, hence their apparent reversal). |
 |
NOTE: Stock cams have two timing marks on them. A different mark is used depending on the
cams location, intake or exhaust. Ensure the correct marks are lined up with those
on the front bearing caps. With both cams in the correct position, the first two lobes on
each cam will be biased towards the center line of the engine, essentially, but not
directly, facing each other. See picture above.
|
| Pull the slack out of the timing chain by pulling to the right
side of the engine. |
|
| Align marks on the camshafts, install the intake timing gear,
lock plate and bolts. Tighten to 9 Nm (6.5 ft lbs.) |
| Next install the exhaust timing gear, lock plate and bolts.
Torque to 9 Nm ( 6.5 ft lbs. ) |
| Check length of timing chain tensioner spring, nominal value
is 159mm ± 0.5 (6.260" ± 0.020") |
| Narrow end of spring faces out to the plug. |
|
| Piston and cylinder are a matched set, and should be replaced
as a pair. |
|
| Install sleeve, if removed, with new seal and tighten to
50 Nm (36 ft lbs.) |
|
| Install piston with groove on slotted end facing up, and
groove on other end facing the exhaust manifold. |
 |
| Tighten piston to 40 Nm (29 ft lbs. ) |
|
| Unscrew nipple on end of plug, replace O ring. Add engine oil
through nipple until oil runs out of plug. Tighten nipple |
| Rotate engine by hand and recheck the cam timing. |
| Lock gear bolts with new locking plates and adjust valves |
