clogged radiator

[KHK]

can a clogged radiator be rescued?

Not mine, its my friend's car's radiator. it gets clogged by sort of too much engine sealer; tried to back flush with water but not work

any idea?/thankyou

[KHK]

some experience on using engine sealer :

my friend and I trying to stop coolant leaking into the combustion chamber
we used engine sealer
at the beginning, it worked, and no more white exhaust
but we continued to empty the whole bottle into the radiator

OK then we test drive the car, OH !! engine temp went to the red H
we found reserve coolant bottle was hot and full and boiling
then took the radiator off and test the water flow in and out
conclusion-->radiator get clogged

Question :
1) is engine sealer rubbish?
2) did we use more than enough sealer?

[Subaru ETA]

so the headgasket is leaking and you used sealer??? why did you not just replace the gasket???

[KHK]

gasket may have a problem,
or the engine may have crack
we don't know which one (or both) is the cause
however we are told engine crack can't be repaired

the sealer claims it can seal off minor gasket leak or minor engine crack
so we tried and end up clogging the radiator/Grrr

[Subaru ETA]

well i would have put a new gasket on it whiloe it was apart. if the head was warpped and cracked thats a different story.

you can take the rad to a radiator shop and get them to flush and check it