I replaced the thermostat today after work. Now that I had the right deep socket to get those threaded nut head bolts off the thermostat casing, I had no problem replacing it. The temperature seems to be reading correct now on the in dash gauge.
But I still have an annoying ticking that happens when I start the car after its been sitting for a while. I have a feeling its an oil lifter, so I put some seafoam in the crankcase. I figure I'll drive it back and forth from work tomorrow and do another oil change to get the crap out. I used 'pennzoil synthetic oil/with cleaning additives' in my last oil change a week ago. I figure the engine will be pretty cleaned out with the cleaning additives in the oil along with seafoam, but the oil probably looks like crap already and will need to be changed again (especially since I put seafoam in it).
If the engine still ticks after I change the oil again, then I'll have to take it to a mechanic to check it over. I hate cars.