[vettestr]

Snake,
Your gauge is accurate as now verified and engine is not staying at T-stat value when running down the road.

Lets go step by step on a few tests. If you start a cold engine and you let her idle it heats up. When gauge or pyro shows about 120 or 130 shot the T-stat housing with pyro to verify. Now shoot top rad hose a few inches from the rad. What does it read on temp? If it shows something close to engine or the 120/30 on gauge your T-stat is already open or is being bypassed somehow.

If engine heats up to about 160 on idle but rad temp on a cold start up is still outside air temp the t-stat is closed and should be able to monitor the temps and see her open and heat coolant in the rad. T-stat should close now that cold rad coolant has entered engine and flow stop. With cooling fans running and t-stat closed you should see rad temps drop until cycle of t-stat opening and closing starts again but fans must be on to see the temps vary.

What happens when you watch this with your pyro?