Knocking normal?

370zFORme!!

By your description, I don't think we have the same issue. You are saying it happens every 3 econds or so correct? Try and post a video. My sound is more of a ticking sound and it happens throughout the RPM range and gets faster as RPMs increase. I have noticed this only happens when the engine has been run up to operating temps. The sound is also very apparent when I turn the car off and let it start cooling down and turn it on in the middle of the cool down process. The field service engineer said it was running within factory specifications and that nothing could be done about the ticking. Since switching to redline synthetic motor oil, and getting an F1 exhaust, I barely hear it anymore unless I try to listen for it. Redline really helped immediately, but the ticking noise comes and goes at its own discretion. Hope that helps.

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87' Honda Civic Hatchback: Kaput @ 288,000 miles, 90' Toyota Celica: Kaput @ 175,000 miles, 93' Mitsubishi 3000GT VR4: Kaput @ 138,000 miles, 06' Scion Tc: Traded in @ 64,000 miles, 10' Nissan 370z: Traded in @ 25,000 miles, 12' Subaru Impreza Sti: Current.