to replace my t-stat and temp sensor?

 

To replace the temp sensor you need to drain all your coolant out. What you could do is remove the radiator cap and pull the temp sensor. Most of the coolant will drain from the block there.

 

Which coolant temp sensor? The one in the head, or the one in the water pump? You need to get the coolant level below whichever one you replace. I wouldn't pull the one on the water pump out and risk coolant running all over the Opti. Same with the t'stat. Doesn't take much to drain the coolant level below the housing, and that way you minimize the risk of dumping coolant on the Opti and ruining it. Play it safe.

 

I'm replacing the one in the WP. I'm having a problem where my fans won't turn on at the propper temp. Since that sensor is the one the PCM uses to know when to turn the fans on and off, I'm gonna out a new one in, along with a 160* t-stat. The guage works fine (which runs off the head sensor).

as of right now I have the fans hard wired to stay on all the time.