That would shorten the oil pressure lines to near normal, and remove what is causing the higher than normal pressure at the filter stand. The front pressure relief is set at 144 pounds. I bet the relief is standing open to some extent, the whole time the oil is warming up. At the other end of the oil pressure loop is the stock oil pressure regulator and it is not going to open until it sees 71 pounds or whatever it is set at. Once off idle (about 600 RPM) the stock pump has some excess capacity and could support such a situation. So resistance to flow by the long runs and the cooler could be producing a huge amount of pressure. If you are measuring oil pressure on the engine, you would not see that pressure on the gage.

 

So long as the engine is at idle or low speed this may not have been a problem. If the engine were to rev up a bit oil pressure could have gone to a bit over 144 pounds while showing 71 pounds on the gage.

 

This is peculiar to Mazda, where the regulator is at the end of the system rather than inside the pump where it is supposed to be. Similar to FI reulators on the end of the fuel rail, that can blow apart and set the engine on fire.

 

This must be a Renesis. The "O" ring would have blown out of a 13B.

 

Lynn E. Hanover