coolant temp sensor

I have a 2001 silhouette that recently when I am ideling the temp gauge will go upto 3/4 ways that is as far as I have let it go. when driving the needle goes down.
I have noticed when at home letting it idle the cooling fans dont kick in
the cooling system has been flushed, 12v have been applied to the fans and they work also I have applied the 12v to the relays and each one clicked not sure if there is any other test for them. Is the coolant temp sensor the next thing to look at? does it sit on the drivers side of the engine is there a test for it, how do you remove it.

Your symptoms are indicitive of air stuck in the line or low coolant. Try to properly bleed all the air out. If that still does not fix it, you may have bigger problems such as a coolant leak or head gasket issue.

I agree could be air in the system or thick coolent. Try this next time it does it while idling just rev the engine and watch the the temp drop real fast...if so try adding some more water.