I have a 98 Expedition 5.4 in which I just changed the heater core.
All seems to be working fine, but when I shut it down, it makes a running water sound at the heater core. It sounds like a babbling brook or as if you turned a water bottle upside down to empty it.
It makes the percolating sound for about 30 seconds, almost as if the coolant is settling, or emptying from the core itself.
There are no leaks anywhere and my fluid level remains constant after running many heat cycles.
It seems to me as if air may be trapped.
I have done many burping techniques, but the situation remains the same. It is more noticeable if I shut down while the heater blower is running, than it is if I shut down with the fan off. With the fan off, the sound is still there, but it is slight and subtle.
All seems to be working fine, but when I shut it down, it makes a running water sound at the heater core. It sounds like a babbling brook or as if you turned a water bottle upside down to empty it.
It makes the percolating sound for about 30 seconds, almost as if the coolant is settling, or emptying from the core itself.
There are no leaks anywhere and my fluid level remains constant after running many heat cycles.
It seems to me as if air may be trapped.
I have done many burping techniques, but the situation remains the same. It is more noticeable if I shut down while the heater blower is running, than it is if I shut down with the fan off. With the fan off, the sound is still there, but it is slight and subtle.