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Its a 2004 Subaru Impreza WRX 2.0L - Does anyone know what this ticking or knock could be? I think it could be something with the valves but I have no idea. Going to do a compression test and take the oil pan off to see what I can find and check the oil for shavings. Any other ideas on what I can check myself? It doesn't overheat and when it idles sometimes the ticking isn't near as loud. Hoping its not a problem with the pistons or engine block.