No, I have not. I do not have either tool. However, the gauge reads perfect any time the vehicle is moving so I have had no reason to doubt it. I'm a moderately capable home mechanic and surely no expert but it seems to me that getting fans to come on at a proper temperature and stay on until the temperature drops is the answer. I just don't know how to accomplish that. I was hoping the Radiator Fan Timer module would fix it. The vehicle does not leak (or lose) any coolant and has had the head gaskets replaced about a year and a half ago. It's been running great until now.