Abstract: A lubrication system is provided, including a pressure control valve for regulating oil pressure in an internal combustion engine of a motor vehicle. An oil pump for circulating oil through the lubrication system is connected in flow communication with an engine lubrication circuit and a sump. A control valve in the oil pump is slidably movable in response to a control oil pressure. As oil pressure increases, the control valve functions to recirculate some of the oil back into the oil pump. By recirculating the oil, the control valve controls the flow of oil from the oil pump, and thereby regulating oil pressure in the lubrication system. During a cold engine start, the pressure control valve is actuated using a combined oil pressure, where a check valve is used to blend a first pressure prevailing at the outlet of said oil pump and a second pressure prevailing at or near the end of the lubrication circuit and.

Abstract: A lubrication system is provided, including a pressure control valve for regulating oil pressure in an internal combustion engine of a motor vehicle. An oil pump for circulating oil through the lubrication system is connected in flow communication with an engine lubrication circuit and a sump. A control valve in the oil pump is slidably movable in response to a control oil pressure. As oil pressure increases, the control valve functions to recirculate some of the oil back into the oil pump. By recirculating the oil, the control valve controls the flow of oil from the oil pump, and thereby regulating oil pressure in the lubrication system. To provide a more stable response by the control valve, the control pressure used to actuate the valve is blended from a first pressure prevailing at the outlet of said oil pump and a second pressure prevailing at or near the end of the lubrication circuit. In addition, bleed can also be incorporated into the oil pump to increase flow rate throughout the lubrication system.