Let me start of by saying, that my problem is solved. Thursday evening, while driving, I was about 20 miles away from home, when I noticed that the temperature needle was gradually rising. It was at 220 and steadly going up. By this time I was no place to pull over to take care of it, so I had to make it home. I made it home. By the time I got there, the needle was all the way to the right as far as it could go, and the "Check Gages" was on the info screen. After getting into it the next morning, I found that the thermostat failed and the pressure was so great that it busted the radiator on the right side on the plastic piece. I took that to the radiator repair shop and had that fixed for $70. It is amazing that a small $5 part can cause such havoc.

I followed the instructions in the tech article by drilling a 3/32" hole in the side of the new thermostat. Once I topped everything off, the temperature has't gone above 200.

How does the thermostat fail and cause a pressure buildup?
Pressure is regulated by the radiator cap.

If a thermostat fails to open..you will overheat due to a lack of flow in the cooling system. And our radiators commonly fail over time by cracking. The hot and cold cycles expand and contract the composite plastic material and in doing so..cause cracks.

So you think the fact that both the thermostat failing and the rupture in the plastic wall of the radiator is purly coincedental :?:

No.. If the crack was bad enough..you got low on coolant and started to overheat. The stat may not have failed.

I can go along with that. Well, better safe than sorry on the thermostat.