u/Jarekobywatel

USDM blobeye WRX.
Original symptoms:
heavy white smoke,

massive coolant loss,

rough idle,

coolant smell from exhaust.

So we:
removed the heads,

had the heads professionally checked/rebuilt,

installed new Cosworth MLS head gaskets,

installed new ARP head studs,

carefully reassembled everything.

Timing is correct, engine rotates freely by hand, etc.
But after filling the cooling system:
white smoke immediately came back,

coolant appears in one cylinder,

and after sitting overnight, the cylinder is FULL of coolant again.

The engine barely even had time to properly run.
At this point I honestly don’t know where the coolant is coming from anymore.
The heads were pressure tested before assembly.

Has anyone experienced something similar on an EJ205?