I took my exhaust manifolds off this weekend and noticed these sensors under the manifolds.
What do these sensors do? (click links for pictures)
There's one on the driver side that had a single wire attached to it;
Driver side sensor
There's two sensors on the passenger side.
This one next to the starter has a single wire attached to it;
Passenger side sensor next to starter
This one had nothing attached to it. There was a dry rotted plastic housing that crumbled when I touched it.
Passenger side sensor

Thanks

 

Nice pics , better than the blurry ones from phones most guys post up

Temp gauge sender
Knock sensor
Radiator fan switch

 

Thanks vetteoz

I was thinking about replacing them while the manifolds were removed, just because of easy access.
You say the sensor on the passenger side is a radiator fan switch. I'm a little confused on how my radiator fan is working if the sensor for it is disconnected.
Any thoughts?
Also, do you happen to know where the oil pressure sensor is located?

 

The knock sensor and temp sending unit can be replaced fairly easily at any time, but the fan switch is hard to get at if the car has A/C.

There were a number of different electric fan configurations throughout the years. On some, the computer or A/C pressure can trip the fan on, even without that switch. That fan switch in the passenger side head can also turn on the fan(s) when the coolant temp exceeds 238*F.

 

On 85 TPI Vettes at least the computer controlled the fan but the switch was a backup

OP switch is either behind the dist or above the oil filter

I wouldn't touch the knock sensor if it is working ;
they almost always break apart and then you have work to get the remains out of the block

 

I have the same question.... (1987 Trans Am GTA) I have a sensor located above the oil filter and one locates next to the distributor, which on is the oil pressure sensor ??