See post 3 in the linked thread.

I will occasionally hear this when I go into the garage (car off). Normal if that is what it is.

 

This has happened on my 2014 Toyota Venza and 2021 RX350. The noise was different on each and occurred after the cars were not running for several hours. I noticed the noise on each car at different times by having to enter the garage to retrieve something. In the case of the Venza, the noise was coming from the rear hatch mechanism and stopped after I opened and closed the hatch. And yes, previously the hatch was fully shut and latched. The RX had a different noise coming from the rear, perhaps the gasoline pump? I started the RX and let it run for a few seconds before shutting it off. Afterwards, the noise stopped. This occurred only once on each car but now before retiring I open the garage door to make sure neither car decides to do this again. Don't want to wake up to a dead battery. This sounds like a dealer, "we can't find anything wrong it", issue.

 

see post #36 above.

 

From time to time, after I turn off the car in the garage and when come back later, I hear the fan running at the back. I did some research and was told it is the EVAP fan system doing it's leak test on the charcoal canister and purge valve. The car does not have to be in ready mode for this to occur and, it is not a malfunction.

I wanted to ask the group if this is the case or perhaps something else. If I start the car and the turn it off, the fan stops running.

Thanks for your help.