BMW 3 (E46). Manual - part 55
117-1
General
This repair group covers timing chain
and Variable Camshaft Timing
(VANOS) repair information.
The timing chains are lubricated by
engine oil and do not require
maintenance. Worn timing chains and
sprockets can lead to noisy operation
and erratic valve timing. A faulty
tensioner can also cause timing chain
noises.
Note:
See
100 Engine–General
for engine
code and application information.
Special tools
Special BMW service tools are needed
to remove and disassemble the timing
chain, the VANOS control unit, the
camshafts and the valvetrain. Many of
these tools are expensive and only
available through an authorized BMW
dealer. Be sure to read each procedure
thoroughly before starting a job to
determine which special tools will be
necessary.
In addition, VANOS system diagnosis
can only be carried out by using BMW
specific electronic scan tools, such as
BMW DIS or MoDiC or equivalent.
CAUTION!
The VANOS system must be
removed and installed exactly as
described later in this repair group.
Torque wrench w/ flex extension BMW
00 9 250