hello everyone , i recently bought a 08 civic Si its rebuilt title , i noticed the whole radiator support was replaced along with radiator and when a few days after i got it i checked the coolant reservoir and it was empty , filled it up and checked it two weeks after , empty again ! filled it up checked radiator and had noticed this white residue around it ..filled up the radiator and few days after my coolant reservoir is already half empty .

my car has a check engine code for the ECT sensor , i recently found these plugs i'm pretty sure these are the ECT plugs ?

well regardless my worry is cause of the coolant that just goes somewhere cause i don't see leaks ,radiator hoses are really hot, could it be the ect sensors ? my Temp gauge shows it heat up and stays where it should

also noticed a fuse missing ?

thanks in advance !

 

use coolant pressure tester and see does it hold pressure or any sign of leaks.

 

If you are loosing coolant and cant tell where its going, then there is a possibility your car is burning it. I.E.Head gasket. Like ImmaJack said, pressure test your system. It should pump up and stay there. The car hates air in the cooling system and cooling sensors freak out, etc.

Smell your reseviour. Does it smell like exhaust? or ONLY like sweet smell of coolant?