Sir, yung popcorn sound nya medyo mahina lang naman. ang sabi ng mekaniko cause daw yun ng piston. napansin nya kasi medyo below normal level engine oil ko...

saka nung ginagamit ko ito sa manila everyday hndi naman ganun kainit ang emit ng makina.. this past few weeks lang naging ganito after palitan ng temp sender at rad fan motor (forgot to mention--pinalitan ko fan motor kasi nasunog fan assembly ko.. :D)

as for your question, hndi ko na naexperience ang kumukulong tubig or near overheating after palitan ng temp sender.. pero under observation ko pa din.