Is it more like a ticking sound or a heavier sound. A lifter makes more of a light ticking sound and piston slap is a heavier spound (almost like a knock). If it's a lifter, you may have varnish deposits on a lifter. It could also be a piece of dirt that is floating around the lifter and, occasionally, gets stuck in it. Either way, you can probably live with it as long as it goes away after the engine has been operating for a short while. If it's piston slap, it could be serious (or not) but you might want to get it checked by a knowledgeable mechanic. I had the same problem in one of my vehicles recently and it cleared up by itself.
Group: alt.autos.gm Date: Sat, Apr 22, 2006, 7:26pm (EDT-3) From: snipped-for-privacy@gmail.com hello all,
99 Camaro, with the subject motor, 84K miles, religiously maintained this just started happening to me -- when started up, very loud tapping noise, ala stuck lifter or valve after 15 minutes of running, the noise gradually diminishes, then is gone all throughout, factory oil pressure gauge reads its usual psi, car runs like it always has carbon rap ? =A0 piston slap ? =A0 recommendations please... (bummed out, really like this auto)
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