[ScubaSteve1994]

I have a 99 Mustang Gt and I just got this brand new engine with PI Heads, there are two holes on the inner sides of the heads that I have no clue what goes there. Original thought was that knock sensors go there, but only the Dual Cam engine has/requires those. Anyone know what goes here?

 

[Paulie]

That hole is for the cylinder head temperature sensor

 

[ScubaSteve1994]

That hole is for the cylinder head temperature sensor

Is that the same as the coolant sensor?

 

[Paulie]

No, depending on the year it used either coolant temperature sensor or a cylinder head temperature sensor. 1999 2 valve uses a coolant temperature sensor located in the intake manifold.

 

[Shauncb]

Yes cylinder head temp sensor, it would only use one but because 2v heads can be swapped side to side they both have a provision for the sensor.