Thx for the thought I did pull out and tested it, in the house stove in pan of boiling water it did open up. As to being installed upside down According to my understanding (which could be wrong) the bottom side goes down closest to the engine., if that wrong please let me know. I did get a digital termo gun warmed up to 220 degree (according to new gauge) all readings where rad hoses ,heater hose top /bottom where under 200. I have the idea either the gauge is defective or I installed it wrong .(do not how it can be wrong for it does record changes in temp. Any more sugg. will be appricated
