Water pump?
now for some reason the sound goes in and out on the video but its constant when the car is on
I really don't hear what you're talking about.
If its a squeak or churp somewhere......take the serpentine belt completely off, start the engine for a minute and rull out an internal engine issue if the noise is NOT there.
Then I would take the a/c belt off...then put the serp belt back on and start it up. Rule out the A/C pulleys, compressor and tensioner....if the noise IS STILL there.
I've never heard of a water pump making noise. Probably a pulley or a tensioner.
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