Skyhigh82

While replacing the starter I noticed that the (Knock/Detonation/ESC) sensor terminal was broken off. When I removed it I noticed a thin aluminum seal inside the hole covered up half the hole but radiator water was coming out. Should the seal be replaced or should I just take out the other half and apply sealant to the new sensors threads? What does the sensor do anyway?

Twin_Turbo

the sensor screws ijnto a hole that is originally designed as a coolant drain. There should not be anything blocking it. Just install a new sensor and fill up the cooling system. The knock sensor is a " microphone" it listens for engine knock (detonation) and sends a signal to the ESC (electronic spark control) which interprets the signal and in its turn sends a signal to the ECM, then the ECM instructs the EST (electronic spark timing) aka the module in your distributror to retard the timing in steps untill knock signal is gone.. then it starts to advance again untill the preprogrammed settings are set or there's knock again.