I'm a bit perplexed. Maybe some of you brainiacs can help. I recently completed a successful lifter R&R + top half restoration (i.e., replace whatever looks old) on my 95 SVO GT40 GT. The ran like a champ for 1 week. Then the problem started. This past Saturday it was 105 degrees outside. As I was driving around the neighborhood my car started to get a lot hotter than it should be. The temp gauge was on the "A" in "NORMAL." At this point I shut the car off because it demonstrated no signs of cooling down. I cannot understand what the problem is. In order to be helpful, below is a list of what I have done to diagnose this issue so far. - New 180 balanced thermostat - New bypass hose - New Rad cap. - Made sure system was purged of air (sitting nose up & heater full blast). - Performed compression test for rings prior to this concern (all cylinders were spec). - Checked timing (factory) - Checked for KOEO codes because this tests the fan's 2 speeds. Fan worked great, no codes. - Pressure tested Cooling system to 16psi (tester from Autozone). After about 2-3 minutes the pressure was at 14.5psi. Question(s): how long should the system hold pressure? I can observe no leaks on the ground, nor any wet spots on the engine, or coming from hoses. I've checked several times while the system is pressurized yet observed no leaks. What is my next step? Your help will be much appreciated.