2000 Ford F-150 Q&A
2000 Ford F-150 Question: Noise in heater core over 2300 rpm.
Replaced heater code and coolant flush. Now have a noise under dash at RPMs over 2300. Sounds like squirting water through a hose. Have driven this way for a month now. No noise under 2300. Also can not hear it in engine compartment, only in cab with doors closed. Possible to have air trapped in core..? How can I bleed the air..? Thanks! - jsnuck
Its very likely that's what is going on, there is an air pocket in the heater core. With the engine off and cool, one way is to take one of the heater hoses off and use a pressure tester to push coolant through the core while blocking the open hose with pliers or a finger, and then switch it and block the core with your finger while bleeding the hose. With a fairly new tool that most shops have today, "The Air Lift" we fill cooling systems by first pulling the system into a vacuum and then letting the vacuum draw the coolant into the whole system. Without these tools another way would be to remove one heater hose and attach a piece of extra hose to the heater core, now pour coolant into that hose which will fill the core and push air out of the open hose. - cardocIII
Did you install a FORD (oem) heater core?? - pushrod