Tips for Stopping VVTI rattle on Startup? in Aurion / TRD Aurion Club Posted Friday at 10:17 AM · Report reply This topic has been covered in earlier threads. You should be able to search this Forum. I have had better results doing a Google search with results for this Forum. Members have posted their various results. Changing viscosity of oil either higher or lower can produce a good outcome. It varies upon the condition of the engine. What works for one engine may not produce the same desired outcome in another. Sometimes a matter of trial and error. If ever I remove the valve cover, I will take the time to check the VVTi controller particularly that the bolts are nice and tightened.