Water sound from inside the dash

alright guys first post here hope you can help me...about a month ago i attempted a flush to my radiator i drained the radiator and took off the thermastat stuck a garden hose in the radiator and it came outa the therostat hole until it was clear replaced thermo and new cap filled her up with 50/50 mix and now i have a water noise from under the dash...i tryed to burp it as someone told me how and the coolant just flows out and i just refill what drained out...also the noise can b heard when i accelerate and the truck dosent overheat at all. if you can help me out since i hear dex cool is junk i dont want it to i guess gunk up or w/e

99 Ls blazer 4x4 95000

Brian

Brian, This link should help ya...

http://www.automotiveforums.com/vbulletin/showthread.php?t=469926

thanks man funny thing is i saw that post and did it i even put a board on top of the passenger ramp and i got nothing but coolant everywhere and again refilled what spilt out and it acually got worse from the water rushing until the t opened to rushing all the time lol i always seem to have the problems that are abnormal

Clogged heater cores also cause this and are common. I use 3' of 5/8 and 3/4 heater hose. Cover the dist with plastic so no water falls on it and gets in and then simply disconnect the hoses at the heater core at the firewall and tie them up so coolant is not lost. Connect 3' sections hanging out the fender and flush with a garden hose and hold the garden to heater so not too much pressure (core could blow) and run till clean then switch to other hose and flush the other way. When clean reconnect and run making sure the rad is full and overflow res full to hot line when cold - ensures air will not get in there.