i was doing my headers gaskets and inbetween 4&6 there is a little gold looking plug coming out and there was a black wire that fits on to it just hanging arond it, anyone know wut this is?

motor is 305 tpi 88 Iroc

 

It is located where temperature sensors can be fitted into the heads. Sometimes it can be used for the knock sensor, but not normally. If you have a temperature sensor in the thermostat housing, you don't need the second one, unless you want a spare temperature guage.

A temperature sensor has a spade connector, a knock sensor has a round special connector. I'm sure you know it isn't gold, just brass.

There are tapped holes in the sma e place in both heads.

You have to plug off the holes and if a plug is not available people use old temperature sensors to plug the hole.

If you leave it unplugged coolant comes out when you refill the system.

The knock sensor fits near the bottom of the engine normally.

 

For the passenger side fan, the thing in the head is a temprature switch to turn the fan on and off.

 

Ah yes the pesky fan switch, I forgot about that. Luckily I don't have an electric fan.