240sx354
09-29-2010, 08:12 PM
Ok, i am a bit worried at this point... I just rebuilt my S14 SR20...Fully built...in the head i have Tomei 260* cams with BC springs and retainers...when i FISRT started the car and drove it for about 30mins everything was quiet, brought the car back to my house and let it cool down...started it up again and went to take off...it started tapping everytime i lifted off idle i didnt know what to make of it so when i brought it to the shop to get tuned we tried to diag the noise...so i unplugged the VTC solenoid and supplied power to it with the engine running...sure enough the cam gear started slapping like an hooker...I ordered a new cam gear and am having it overnighted because my car is sitting on a dyno right now but my question is really this. i read this...
Stock Nissan variable Valve Timing Control (VTC) intake camshaft sprockets 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 sprocket, this wears its internal o-ring seal and eventually leads to an oil leak. The noise is typical with high-mileage sprockets 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.
in it it states that aftermarket springs can cause the rattle...my concern is even though it was quiet for a short time and i could drive it around for a bit before it started to fail on me...once i replace the cam gear with a new one will it still make that noise? or will the new one be strong enough to work with the springs...btw the Tomei cams i bought are the VTC friendly cams.
Thanks any advice would be appreciated! :)
Stock Nissan variable Valve Timing Control (VTC) intake camshaft sprockets 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 sprocket, this wears its internal o-ring seal and eventually leads to an oil leak. The noise is typical with high-mileage sprockets 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.
in it it states that aftermarket springs can cause the rattle...my concern is even though it was quiet for a short time and i could drive it around for a bit before it started to fail on me...once i replace the cam gear with a new one will it still make that noise? or will the new one be strong enough to work with the springs...btw the Tomei cams i bought are the VTC friendly cams.
Thanks any advice would be appreciated! :)