I can hear the sound of water inside the engine bay sloshing around. As far as I can tell it is rpm related and I usually can only hear it below 3000 rpm. No check engine light or other issues...help?

 

Well there are a couple of things that contain water in the engine bay, including the engine. I would suggest opening the hood and pinpointing where the sound is coming from first. With the amount of info you provided thats about all the help I can give at the moment.

 

I think one of our cars makes a similiar noise. It doesn't happen often. It sounds like water moving around. I also noticed it only happens when you take off when its warming up. I don't drive it much so Idk. I hope someone else has an idea perhaps for both of our problems.

 

If you can hear it inside the cab, this is usually something to do with the heater core and/or air pockets in the cooling system. Had this issue with my 2001 Ram 1500 after replacing the water pump.

The method to test this in the older trucks was jack up the front end so that its sitting far higher in the front than the rear (or park it on a hill side), remove the radiator cap, and let the truck idle until warm. Once it reaches operating temp, the coolant will begin to cycle through the engine. If pockets of air are present, they should go to the higher side... which now has the open hole for them to escape from since you removed the cap. If they are present, you may see substantial bubbling. In really bad air pocket issues, you will see some overflow of coolant. After the bubbling is done, replace any coolant that overflowed, put the cap back on, and you should be good to go.

I am assuming you can do this with these newer trucks as well. Do not warm up the truck and then remove the cap! Remove the cap first. If the system is under pressure, hot coolant could pop out and burn you.