Fuel pump noise?
 

I notice whenever my car starts, or start accelerating from a light when (sometimes), that I can hear what sounds like fluid being ran through tubes, like a lound SWIIIIISH noise.

Haven't noticed it until recently, if it's normal, thats fine. I'm just more interested in what it is...Recently got my engine replaced, before then I never had it/noticed it, and I didn't have have it/notice it until a few weeks after the replacement...

I tried searching but I guess I wasn't using the correct keywords.

The fuel pump in inside the gas tank and under a rear seat, you can't hear it. That noise is air in the coolant and your hearing it move around the heater core. Not a big deal unless it gets real bad. I would live with it till your next coolant change and bring up the issue.

Try taking the radiator cap off when car is cold. Let it run until she starts to over heat. No more air.

Thanks, I'll give that a shot. If that doesn't work I'll do be sure to let someone know like you said expo