For the past few years, we’ve been getting a steady stream of Tech Tip cards regarding noisy valve lifter problems on the Subaru overhead cam (OHC) engines used in their “L Series” (GL and Loyale models). One poor soul was having a devil of a time with a Subaru that would occasionally break out in fits of “clatteritis” at highway speeds. The list of parts that he had already replaced was long, although no cure seemed near. Then the second wave of cards started to come in. “Replace the oil pump and your clattering valve problems will disappear,” several men in the know confidently suggested.