I've been hearing what sounds like water trickling through the engine while inside the cabin of my car, and when I start accelerating it sounds like water is splashing within a container or something. I have 100k miles on my car and i've never heard this before. I'm just wondering could it be water trapped within the vent system?

I did take the engine cover off so I can install my sway bar but not sure if that was muffling the sound before or if this is water trapped somewhere?

Anyone else ever heard this?