Heater Core problem?

When My jeep is cold....even after it's been idling for a while.....when i first drive away and the RPM's get higher there is a bubbling sound that comes from inside the passenger dashboard (like water and air bubbles flowing through a pipe in your basement). It does it even when i turn the heater on before driving away. There is no water on the floorboard or moisture build up on the windshield so I don't think anything is leaking. It only does it when the engine is cold though. It started a little while after i had the radiator replaced. Any ideas?

You have Air inside the system. You need to try to burb the air out. I dont know what year you have so the easiest way is to jack up your front end and take the Radiator cap off start the jeep and let it run for a few minutes and try to refill it while it is running. Might take a few times make sure you have the heater on and on high.

I had the same thing happen to me, whenever I would rev the engine when it is cold (actually didn't matter if it was cold or hot, just first couple times I could rev the engine up) I could hear the sound of rushing water, but I also had a heating problem (I would have heat for like 5 seconds then it would cool down to a luke warm heat). I flushed/reverse flushed the Heater core along with a the radiator and engien block and problem solved. I have a post on here about my problem (if you search my name on here you are sure to find the thread I posted) and also a great tip on flushing the heater core and engine block.