91 Ford Explorer makes popping noise in coolant system after turning off ignition

[Help4adumbone]

I bought an explore with 120,000 and noticed after I ran the heater I heard a loud popping coming from engine. O traced the sound coming from coolant system as the radiator hoses shook as it popped. replaced the thermostat and I noticed the spring was loose do to coolant pressure was popping in coolant lines. No results, so I replaced the heater core and it had a leak and was a little corroded. The easiest heater core ever to replace. 20 minutes. II did not notice as I ran it for an hour or more with the heat on, so I was stoked. But the next day it started again once heated and drove for a minute even while driving. But I still drove 100 miles just cut the heat off as this only happens when you run the heat and it warms and idles or turn off ignition. Many mechanics or dumbfounded and I just don't want to replace radiator if it is not going to work. It never runs hot as gauge registers normal. No other symptoms but maybe heat is not as hot as other vehicles but does work, or leaks, oil looks fresh, no smoke. I am going to replace radiator cap and flush system tomorrow. It cud excelerate a little faster.

 

[Help4adumbone]

I bought an explore with 120,000 and noticed after I ran the heater I heard a loud popping coming from engine. O traced the sound coming from coolant system as the radiator hoses shook as it popped. replaced the thermostat and I noticed the spring was loose do to coolant pressure was popping in coolant lines. No results, so I replaced the heater core and it had a leak and was a little corroded. The easiest heater core ever to replace. 20 minutes. II did not notice as I ran it for an hour or more with the heat on, so I was stoked. But the next day it started again once heated and drove for a minute even while driving. But I still drove 100 miles just cut the heat off as this only happens when you run the heat and it warms and idles or turn off ignition. Many mechanics or dumbfounded and I just don't want to replace radiator if it is not going to work. It never runs hot as gauge registers normal. No other symptoms but maybe heat is not as hot as other vehicles but does work, or leaks, oil looks fresh, no smoke. I am going to replace radiator cap and flush system tomorrow. It cud excelerate a little faster.

I changed t-stat with bleeder whole plus to a lower temp one. Replaced all of the hoses as one was soft. Seemed to have remedied the problem.