diff --git a/game/reconstructed/mech.cpp b/game/reconstructed/mech.cpp
index 32814c7..c724b7f 100644
--- a/game/reconstructed/mech.cpp
+++ b/game/reconstructed/mech.cpp
@@ -572,10 +572,22 @@ int
 	extern int BTPlayerExperienceSimLive(void *owner_mech);		// btplayer.cpp (+0x25c;
 	int noviceSim = (BTPlayerExperienceSimLive(this) == 0);		//  NULL-player reads LIVE)
 
+	// COOLANT-CLAUSE HYSTERESIS [T3 intent-completion, 2026-08-03]: the
+	// binary's clause is a plain `< 0.05` compare -- but this evaluator was
+	// DEAD CODE in shipped 4.10 (never called), so the boundary flap was
+	// never exercised.  Live, a bank fraction hovering at 0.05 under fire
+	// flips the panic-arm mode EVERY FRAME (observed: hundreds of ON/off
+	// pairs), churning the mode mask, the lamp, and the arm audio cue into a
+	// ~10 Hz stutter tick.  The engine's own idiom for exactly this is the
+	// dual-threshold pair (HeatSink coolantActive: 0.003 on / 0.0025 off);
+	// mirrored here: ARM below 0.05 (the binary constant @0049fb50), stay
+	// armed until the fraction RECOVERS above 0.06.  No new members -- the
+	// current ejectPermitted is the state.
+	Scalar coolantGate = ejectPermitted ? 0.06f : 0.05f;
 	ejectPermitted =
 		(liveWeapons < ejectMinWeapons)						// @0x448 floor (inert at 0)
 		|| (liveGenerators == 0)
-		|| (coolantFrac < 0.05f)							// _DAT_0049fb50
+		|| (coolantFrac < coolantGate)						// _DAT_0049fb50 + hysteresis
 		|| (gimped && noviceSim);
 	return ejectPermitted;
 }