Reading the recent posts about oil pressure problems and a clicking noise got me to wondering . . . how do you know when it's a valve clicking, and not something else? I have had small exhaust leaks on almost all my Chryslers. And to me, they sound like "clicking" or "ticking." Most recently, I had an exhaust leak on my '70 New Yorker that some folks SWORE was a bad valve. My uncle, who has many more years experience than I working on cars, told me I was flat wrong when I said it was an exhaust leak. Fortunately, I have heard enough small exhaust leaks to recognize the sound, and I was right on that one (wish I'd bet him some money). But I'm not sure if I've ever heard a bad valve. How can you tell the difference? Someone told me you could listen at the tailpipe, not at the engine, and if you could hear the ticking back there it was a valve. Hmm. Or was that the other way around? Anyway, just how do you know what that clicking is you're hearing?? MM