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.
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 80 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.
Notes about core options:
1. If "Sending Cores First" is selected, we will contact you after you place your order with further instructions. If this option is selected, you will not be charged a core fee, however you are responsible for the shipping costs to send cores in. Your order will not ship until the cores are received and are deemed to be rebuildable (ie. not physically damaged, mishandled or abused). Cores must be received within 30 days of placing the order.
2. If "Cores Required" is selected, you will be charged a core fee of $250.
When shipping your cores, keep your VTC front covers and hardware
to re-use. Late VTC front covers are different than Early front covers, AND, Late front covers are no longer
available from Nissan.