How to Adjust the Valve Lash on Hydraulic Lifters
- 1). Set the shifter in park if your vehicle has an automatic transmission. Place the shifter in neutral, for a manual type. Raise the hood. Disconnect the negative battery cable with an end wrench. Refer to your owner's manual for the proper removal procedure for you valve cover or covers. Use a socket and wrench (or screwdriver) to remove any component over the valve cover, such as the plastic engine plenum.
- 2). Use a socket and wrench to remove the air box housing, if it impedes access to the valve cover. Pull the air box cover and hose away from the area. Loosen and remove any bracket joined to the valve cover bolts, such as a wiring loom, or spark plug wire bracket. Look for and remove any throttle or choke cable crossing over the valve cover, as in the case of a straight in-line 4-cylinder engine.
- 3). Pull emission control hoses from their connections and prop them out of the way. Use a fuel line wrench to loosen the fuel line flare nut, and gently bend the fuel line away from the valve cover. Disconnect any sensor wire from its connector. Remember the sequence and location of all components you removed.
- 4). Use a socket, extension and wrench to remove the valve cover bolts on one valve cover only. Gently pry up on the valve cover with a screwdriver, but do not tear the cover gasket. Set the cover aside. Take an oil tappet plug and clip it around the tappet, so the spring clip clamps onto the tappet body and the middle plunger covers the tappet hole. Do this with each tappet.
- 5). Temporarily reconnect the negative battery cable to its post, hand tight. Start the engine and let it warm up at idle speed. Use an end wrench to to loosen the tappet lock nut, while you hold the adjusting screw with a flat-head screwdriver. Turn the adjusting screw out, counterclockwise until the lifter begins to click. Keep the end wrench steady and immobile.
- 6). Turn the adjusting screw in, clockwise until the click just begins to disappear. Then turn the adjusting nut with the screwdriver 3/4 of a turn further in clockwise: tighten the lock nut with the end wrench at that position. Repeat the same process for all the tappet adjustments on one side. If you have more than one valve cover, shut the engine off and remove the other valve cover bolts with a socket, extension and ratchet.
- 7). Place the oil tappet plugs on the second set of tappets, but place the first valve cover back on the engine and tighten the bolts with a socket, extension and wrench. Adjust the second set of tappets just as you did the first ones. When finished, remove the oil tappet plugs and place the second valve cover back on the engine. Replace and tighten the valve cover bolts with a socket, extension and wrench.
- 8). Reassemble the parts above the valve cover (or covers) that you removed in the reverse order, including the plenum, brackets, cold air box and hose, throttle or choke cables, sensor wires, vacuum or emission hoses. Tighten the negative battery cable with a socket. Test run the engine and listen for any valve train noise.
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