Stock
Nissan
variable
Valve
Timing
Control
(VTC)
intake
camshaft
pulleys
are
non-serviceable
units
that
are
notorious
for
making
noise
and
leaking
oil.
Oil
leakage
occurs
because
the
rear
cam
seal
plate
can
rotate
independent
from
the
pulley,
this
wears
its
internal
o-ring
seal
and
eventually
leads
to
an
oil
leak.
The
noise
is
typical
with
high-mileage
pulleys
and/or
aftermarket
higher-pressure
valve
springs
that
cause
the
cams
to
over-rotate
on
every
cylinder's
intake
valve-closing
event.
This
over-rotation
causes
the
VTC
piston
to
screw
itself
onto
the
VTC
helix
and
overpower
the
piston
return
spring.
As
the
cam
continues
to
rotate,
the
valves
close
and
the
valve
spring
pressure
diminishes
to
the
point
where
the
VTC
return
spring
slams
the
piston
back
to
its
stop
creating
the
audible
tick
that
is
indicative
of
a
noisy
VTC.
By
design,
the
VTC
function
is
to
advance
the
intake
cams
20°
(crankshaft)
from
just
above
idle
to
roughly
5800
RPM
to
increase
torque
in
this
RPM
range.
At
idle
and
high
RPM
the
VTC
is
in
its
static
"zero
advance"
position
which
reduces
valve
overlap
for
smooth
idle
characteristics
and
increases
torque
at
higher
RPMs
-
and
it
is
only
in
the
zero
advance
position
that
the
VTCs
can
make
noise.
True
VTC
noise
can
be
verified
by
activating
the
VTC
solenoids
using
a
ConZult
or
by
grounding
their
green
with
black
stripe
wires
while
the
engine
is
idling.
This
will
cause
oil
pressure
to
build
within
the
pulley,
forcing
the
VTC
piston
to
screw
onto
the
VTC
helix
thus
advancing
the
cam
and
removing
the
window
of
opportunity
to
make
noise.
Typical
VTC
noise
will
stop
entirely
when
doing
this
and
the
engine
will
begin
to
idle
rough
due
to
increased
valve
overlap.
BDE
rebuilt
VTC
pulleys
feature
a
redesigned
piston
return
spring
specifically
engineered
for
the
load
needed
to
prevent
camshaft
over-rotation
with
installed
valve
spring
pressures
up
to
90
lbs
and
permit
full
VTC
function.
Oil
leaks
are
eliminated
by
replacing
the
o-ring
and
positively
locating
the
rear
cover
with
a
dowel
pin
thereby
preventing
it
from
rotating.
Core
Charge($400):
An
additional
$400
core
charge
applies
BDE
VTC
Sprockets,
and
is
charged
at
initial
purchase.
Once
the
Customer
receives
the
items,
they
must
then
return
their
original
items,
in
good
condition
(no
dents
or
cracks
are
allowed
back
as
a
core
credit.
Core
charge
will
not
show
up
on
internet
invoice.
If
you're
sending
cores
in
1st,
please
send
them
to:
BDE
c/o
CZP
Order
#(Insert
your
order
number
here)
65
Walgren
Heights
Drive
Port
Angeles
WA
98363
253-230-8205
