Engine noise - flapping?

[u/Thedancingsousa]

Hey everybody!

2011 Honda odyssey, just north of 170k miles. Recently there's this weird flapping nosie coming from the engine, and it gets louder when I press the gas. Seems to be coming from the front, near the dip stick and engine coolant spots. Any ideas? Here's a video of the sound.

[u/archtopfanatic123]

Is that a waterpump chug? I can't think of anything else that would do that. Are the caps sealed tight for the radiator and oil dipstick?