What you are doing will work however thats not in the owners manual, and it's not the way things are suppose to work. You are not getting enough oil to the upper part of the engine, most common cause is several "O" rings in the oil pan not sealing correctly, thus a loss of oil pressure. Make sure it's the lifters making the noise and not the injectors, the injectors do make a tapping noise and that is normal, however if the tapping is coming from under the black spark plug cover and more than likely the drivers side of the engine, then you more than likely need the hand full of "O" rings in the oil pan replaced. All this is a best guess without hearing the noise.
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Rich K.