I'm running out of options.

I put in a 34" radiator.

I put in a TBSS waterpump with t-stat.

I put Virgils reservoir cap on to make sure my cap wasn't faulty.

Filled it with coolant and ensured there were no air pockets.

The gauge is all over the place. The PLX gauge reads similar to the cluster gauge, so I don't think it's a gauge problem.

Examples of what it's doing:

I can be driving home from work and everything is fine. Temp will be right at 210 or so. This can be on a hot HOT day. Maintains temp. All of the sudden it will spike. 240...250...Then all of the sudden it will drop back to 210ish. That's what makes me think it's the temp sensor.

I just started it up, cranked the AC and let it idle for a few minutes. Checked it and it was fine - right at about 210. Put it in drive to take it around the block and it spiked to about 230 almost immediately. Stopped, revved it a couple of times, and it climbed to about 240 and then kept climbing to 260.



Like I said, about the only thing left I can figure is the coolant temperature sensor. So the plan is to put in Virgil's sensor and see if that fixes it.

Any other ideas?