My lexus GS 450h 2007 has a rattle in the engine on start up

Most often this is the exhaust baffle rattling. It goes away after a few moments after warmup.

Most likely timing chain rattle, have a car savvy person listen to it on first start up... May need to leave it with a mechanic!

I have the same car with the same problem. I've owned my car since 2006 and it has never made this noise before. It sort of shudders when it starts along with the slight rattle. It only does this when it starts in engine mode vs battery mode.