Vacuum Noise Up Hill?

I’ve been scouring the forums for answers but can’t seem to find one.

My 2011 Rock Warrior 5.7 is making the “vacuum” like sound you normally hear on startup, but it’s doing when at higher rpm’s while driving up hills. Does anyone know what this means?

I had the local oreillys check for codes or code history and nothing came up.

 

That is the fuel pump sucking hard going uphill.

 

Would it be doing that with a 3/4 - full tank?

also for context - I just noticed it starting doing this a few months ago. Thanks again for your insight!

 

bump

 

Do you have an intake?

 

No everything under the hood is stock. The noise sounds closest to a vacuum noise but it has the rhythm of a miss, if that makes sense. Pretty erratic.

 

Interesting- I'd check for vacuum leaks on hoses etc. The vacuum sound on startup is typically the secondary vacuum intakes.