how can I test my coolant temp sensor (in my manifold) to see if it needs replacing?

my usual high-tech troubleshooting method of "replace the part and hope it fixes the problem" gets costly. this time i'd like to use my brain before spending my money.

thanks guys.

 

You need a DVOM (anything that can read ohms) and a second known good (and accurate) gauge. Once you have those 2, start the car when cold and watch the sensors resistance.

Cross reference with this chart (chart courtesy of Vader):

 

I just bought a CTS. It was only $16.
It would have been cool to test it though.
My car ran hot a few days ago, so I am
in the process of replacing the cheap
stuff.

What do you use to coat the threads
of the CTS and fan switch? Auto parts
lady recomended anti seize.

 

Sensor friendly thread sealant.

 

Stekman, thanks for this info and chart.