WELL THATS WHAT I WAS THINKN, JUST MAYBE A RELIEF VALVE. THERE IS A OIL THERMOSTAT THAT IS SUPPOSED TO ACTIVATE WHEN THE OIL IS TOO HOT. BUT THAT NEVER SEEMED TO OPEN, SO WE JUST TOOK IT OUT THINKING THAT THE OIL WAS NOT CIRCULATING, THEREFORE OVERHEATING THE OIL AND THUS THE OIL PRESSURE DROPS, BUT STILL NO CHANGE. IS THERE A VALVE INSIDE THE OIL FILTER HOUSING THAT COULD BE STUCK OPEN???