Well to make a long story short I pulled the rad and condensor to do the opti swap.

Filled back up w coolant, left both bleeder screws open til I had coolant coming out of them. On first fillup it only held 2 gallons.

I took some extra w me just in case and went for a drive.

I drove 95+ on the freeway for about 15 miles, got to our little spot across the border in "mexico", raced 2 cars. Drove all the way back to town, went to a different spot and raced, cruised etc.

Put over 40 miles on the car and never a problem. Was watching the temp gauge the whole time and it was where it always is and the heater was working great.

Parked the car to grab a bite to eat and when I left I was driving super easy. 1500 rpms for about 2 miles and I look down and the temp gauge is pegged.

I shut it off immediately and coasted into a parking lot.

Had friends bring me some water and after it cooled down we added about a gallon.

That's all it would take so I filled up some more jugs and headed home, about a 35mi drive each way.

Drove it home and checked it this morning before startup and it only took about 1/4 of a gallon.

Drive it around town all day and tonight so by this time I have over 85 miles and no issues. Well I left the gas station and I notice it getting hot, it got close to the red mark and then fell back to normal like a rock, like the thermo opened right?

Well I left my buddies house and it did it again, started getting hot and then fell like a rock. I was watching it really close by this time.

We went to the store to rent a movie and when we left it did the same routine, except this time, it didn't cool down. I never let it touch the red but it got hot enough to start boiling over a little.

I think maybe the thermostat is sticking so we went and got a new one and put it on. It cooled down after I topped it off w coolant again, held about 1 1/2 gals but I'm sure it boiled that much out.

At this point I've driven the car about 10 miles and the temp is perfectly normal and does not appear to be leaking anywhere.

So... you guys think I just had a bad thermostat the whole time, or do I have bigger issues to worry about?

Reverse Flow Cooling FTL

 

sounds like a bad thermo. just keep an eye on the new one

 

Air bubbles too maybe. If you kept having to add water there is a good chance that during that time an air bubble got into the sensor reading high and then once it shot past, the temp. would drop as well. Could be a combo of thermo and air bubbles. Like hitman said, just keep an eye on it for it while. Also, in the morning before you go anywhere or do anything, pop the hood, open the cap and make sure it's full for a while before going anywhere. Do that a few times until you are pretty confident that it is full.

 

Why don't you test the old thermostat if it's bothering you so much?

Throw it in a pot of boiling water.

 

Its not.

 

Well I was sittin in a parking lot a few minutes ago talking to the previous owner on the phone about this issue and I noticed the temp start climbing. It got to about 220 and then dropped back down. Looked outside and it had spit out a bunch of coolant on the ground :-(Took about half a gallon to fill it back up. Looks like it is wet over by the recovery tank like its spitting it out there. The inner fender and battery tray is all wet.I'm getting tired of this, I wonder if it will eventually get bled out? Guess ill just keep topping it off and watching the temp

 

I don't know...something is going on. You really shouldn't have to keep watching it and topping it off. Once it is full and bled that should be it. I just say check it because you were having a couple issues. But for it to keep bubbling over isn't right. Are the fans working for sure...all the time? Bad temp. sensor maybe for the computer? All the routing for the coolant hoses is still stock correct right? Do you still have the air dam on the front of the car under the radiator?