Systems and methods for operating an engine with an oil pump that supplies engine oil to various oil consumers in an engine are presented. In one example, a displacement of a variable displacement engine oil pump is adjusted to provide sufficient oil pressure throughout the engine, but low enough to conserve fuel.

Systems and methods for operating an engine with deactivating and non-deactivating valves are presented. A common engine block and cylinder head may be used in two different vehicles where a first of the two different vehicles includes valves of selected cylinders that are always active when the first of the two different vehicles is operating. The second of the two different vehicles includes valves of selected cylinders that are always active when the second of the two different vehicles is operating, the valves of the selected cylinders of the second vehicle different from the valves of the selected cylinders of the first vehicle.

Systems and methods for operating an engine with deactivating and non-deactivating valves are presented. In one example, mode changes between deactivating cylinders is based on an amount of time a valve is deactivated, and the longer the valve is deactivated the sooner cylinder valves may be deactivated. If the amount of time the valve is deactivated is short, the time that valves may be deactivated may be delayed.

Systems and methods for detecting and controlling knock in an engine are presented. In one example, engine knock sensors are selected based on whether or not certain cylinders are activated and combusting air and fuel or deactivated and not combusting air and fuel. Output of selected knock sensors is the basis for adjusting engine spark timing.

Systems and methods for operating an engine with deactivating valves are presented. In one example, deactivated valves may be reactivated to increase a rate of camshaft phase indexing relative to engine crankshaft position. However, if a desired rate of camshaft indexing is low, the engine cylinders may remain deactivated based on the low rate of desired camshaft indexing.

Systems and methods for operating an engine with deactivating valves are presented. In one example, deactivated valves may be reactivated to increase a rate of camshaft phase indexing relative to engine crankshaft position. However, if a desired rate of camshaft indexing is low, the engine cylinders may remain deactivated based on the low rate of desired camshaft indexing.

Methods and systems are provided for aging a new plastic fuel tank in a vehicle. In one example, during a plug-in event to recharge a battery of the vehicle, the fuel tank is isolated and the fuel pump is actuated to agitate fuel within the tank and increase fuel vapors until the plastic fuel tank becomes aged to a predetermined degree by fuel vapors generated therein. In this manner, the fuel tank is aged more rapidly, resulting in more accurate fuel level readings and less noise and vibration.

Methods and systems are provided for aging a new plastic fuel tank in a vehicle. In one example, during a plug-in event to recharge a battery of the vehicle, the fuel tank is isolated and the fuel pump is actuated to agitate fuel within the tank and increase fuel vapors until the plastic fuel tank becomes aged to a predetermined degree by fuel vapors generated therein. In this manner, the fuel tank is aged more rapidly, resulting in more accurate fuel level readings and less noise and vibration.

Systems and methods for operating an engine with deactivating and non-deactivating valves are presented. In one example, engine volumetric efficiency actuators are adjusted in response to a request to activate engine cylinders so that engine intake manifold pressure is drawn down quickly toward its normal state at the engine's present speed and torque.

Systems and methods for operating an engine with deactivating and non-deactivating valves are presented. In one example, engine volumetric efficiency actuators are adjusted in response to a request to activate engine cylinders so that engine intake manifold pressure is drawn down quickly toward its normal state at the engine's present speed and torque.