Mystery noise

[kwromeis]

I entered my garage to find a vibrating noise coming from our 2023 Crosstrek. The Crosstrek was parked in the usual location with the engine off, no doors open or any other irregular situation except the for the humming, rattling noise coming from the back-side of the vehicle. I could not feel a vibration and the noise stopped after several minutes. This has happened twice, that I know of, since we picked up the car at the end of February, 2023.
This is the first Subaru we have owned and the first mystery. I called the service department thinking they would know exactly what the issue is and tell me not to be concerned. The mechanic said he never heard of such an issue.

 

[Scooby22GT]

Hello...I have a '22 that has done this very thing once and to my knowledge, the only motors back there are the fuel pumps. The humming noise is very similar to an air suspension pump. I shot a short video of it to show the service dept. next time I go in for service. When I entered the car and put it in pre-ignition, the noise stopped.

 

[Ecmbuster]

The installed engine is a mystery?
2.0L 4-cylinder
Direct Injection

2.5L 4-cylinder
Direct Injection

FACT!
Any direct injection engine that is HOT and has been driven a distance AND the under hood temperature are HOT including fuel temperature, will have the fuel pump(s) remain ON (maintaining pressure) to prevent a "Hot Soak Condition" and or "fuel vapor locks".
When fuel temperature cools, the pumps disengage.

 

[Scooby22GT]

Yeah that is a fact. However in my case, my car sat for a couple of days. I have another car to use as my daily.