BDE Rebuilt VTC Pulleys

Early VG30DE(TT) ('90-'93NA, '90-'94TT)                 Adjustable, Late VG30DE(TT) ('94-'95NA, '95TT)

Click here to identify your VTC type

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 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.


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