On the 3.5 start up rattle can be the timing chain tensioner however the more common item is a worn VVT cam sprocket lock pin that doesn't latch, then the oil leaks down overnight and lets extra clearance develop between the parts inside the VVT housing. That gives you a start up rattle because of the metal slapping metal.
Sounds like this: www. Youtube. Com/watch?V=mMp7LELtNb4
Look up Toyota T-SB-0094-09 for information on it. Easiest one to read is on Toyota Nations site. Next you might want to see if yours ever was recalled and repaired, if not you might want to ask about it as it is not a fun repair.
Tuesday, June 23rd, 2020 AT 7:47 PM