pressure should be at 30 to 32 at idol 10 to 15 is not good. what kind of oil do you use? only 30wt is required. I use a high volume pump instead of pressure, do to the fact that pressure will blow out gaskets when you rev up. a hot motor will drop your pressure maby a few pounds lower but not more than 5lbs. your pump could be weak but if you have high milage then bearings should be considered also.