External oil groove on a hydraulic lash adjuster

1. A method, comprising:

closing a control valve to flow hydraulic fluid from a first annular gallery to a second annular gallery of a hydraulic lash adjuster via a metered hydraulic fluid passage positioned between the first and second annular galleries and on an outer surface of a hydraulic lash adjuster intermediate spool; and

opening the control valve to flow hydraulic fluid directly to the second annular gallery from the control valve.

2. The method of claim 1 , wherein flowing hydraulic fluid through the metered hydraulic fluid passage includes the hydraulic fluid being contained within the metered hydraulic fluid passage and a bore of the hydraulic lash adjuster without flowing through internal passages of the hydraulic lash adjuster.

3. The method of claim 1 , wherein opening the control valve increases a pressure of the second annular gallery.

4. The method of claim 1 , wherein switching a position of the control valve inverts a direction of a flow of hydraulic fluid in a second annular gallery conduit.

5. The method of claim 1 , wherein opening the control valve deactivates a cylinder of an engine.

6. The method of claim 1 , wherein closing the control valve results in the first annular gallery being greater in pressure than the second annular gallery, and opening the control valve results in the second annular gallery being greater in pressure than the first annular gallery.

7. The method of claim 1 , wherein hydraulic fluid continuously flows directly from a pump to the first annular gallery during engine operation.

8. A hydraulic lash adjuster, comprising:

a one piece plunger body coupled to a first gallery for mitigating lash in a variable displacement engine and a second gallery for providing hydraulic fluid to an auxiliary valve actuation system,

wherein the first gallery is located on a first, lower annulus and the second gallery is located on a second, upper annulus of the hydraulic lash adjuster and where the first annulus and the second annulus are vertically separated by an outer diameter of the hydraulic lash adjuster body,

the first gallery is fluidly coupled to a first conduit and the second gallery is fluidly coupled to a second conduit, and

the first gallery is fluidly coupled to the second gallery via a metered passage in an outer body of the outer diameter of the hydraulic lash adjuster body.

9. The hydraulic lash adjuster of claim 8 , wherein the second gallery is further fluidly coupled to a passage of the one piece plunger body.

10. The hydraulic lash adjuster of claim 8 , wherein the metered passage allows a metered amount of hydraulic fluid to flow through from either the first gallery to the second gallery or the second gallery to the first gallery.

11. The hydraulic lash adjuster of claim 8 , wherein each of an opening of the first gallery, an opening of the second gallery, and the metered passage is angularly and axially aligned along the hydraulic lash adjuster.

12. The hydraulic lash adjuster of claim 8 , wherein at least two of an opening of the first gallery, an opening of the second gallery, and the metered passage are axially aligned while being angularly misaligned along the hydraulic lash adjuster.

13. The hydraulic lash adjuster of claim 8 , wherein the first annulus and second annulus have substantially equivalent diameters, and wherein the outer diameter of the hydraulic lash adjuster body has a greater diameter then a diameter of the first annulus and the second annulus.

14. The hydraulic lash adjuster of claim 8 , wherein the first gallery and the second gallery are not coupled inside the hydraulic lash adjuster.

15. A system, comprising:

at least one hydraulic lash adjuster disposed in a residence bore;

at least one switchable cam follower actuated by hydraulic fluid fed through a plunger of the hydraulic lash adjuster;

a first gallery and second gallery, where the first gallery and second gallery are separated by an outer diameter of the hydraulic lash adjuster body;

the first gallery located on a first annulus and the second gallery located on a second annulus, where the annuli are fluidly connected by an external passage along the outer diameter; and

a controller with computer readable instructions stored in memory for:

controllably supplying hydraulic fluid to an auxiliary valve actuation system via opening a control valve to flow hydraulic fluid directly to the second gallery to increase a pressure of the second gallery, and where the second gallery is fluidly coupled to the auxiliary valve actuation system.

16. The system of claim 15 , wherein the controller further comprises computer readable instructions for closing a control valve to disable flowing hydraulic fluid directly to the second gallery and to decrease a pressure of the second gallery.

17. The system of claim 15 , wherein the second gallery is fluidly coupled to the plunger.

18. The system of claim 15 , wherein the first gallery and second gallery are fluidly coupled to a sump of the engine.

19. The system of claim 15 , wherein the first gallery and the second gallery are in fluidic communication outside of the hydraulic lash adjuster body.

20. The system of claim 15 , wherein the control valve is positioned in a passage fluidly coupling the second gallery to a sump, and wherein the passage is downstream of a conduit leading to the first gallery.