Coming home from my trip to Texas last week and I see my isspro mechanical water temperature gauge setting about 215* but the gauge in my cluster and my ScangaugeII both reading 188-190. I check my gauges periodically when im driving my truck so I know it was not doing it very long. We stopped to run through the Chik-fil-a drive through and after about 10 minutes or so being back on the road I noticed it. I was running 80 so I backed off down to 70 and it came down a little, maybe 210 or so. I kept a hawks eye on it for the next 10-15 minutes and it just dropped to 195 or so like normal. I watched it the rest of the trip and since but it has not come out of the normal range. The sensor is in the port between #2 and #3 cylinders. Coolant and oil all look good, block looks good but it has me worried a little. I hope its just a faulty gauge, to bad Di Pricol went out of business because these Isspro are not the same quality they were but that is another thread.

You need to verify which gauge is correct. Use a IR heat gun and do a couple of quick measurements with the engine off after its fully warm and see what you get.

The mechanical gauge gets up over 200 after I shut the engine off.