1992-1999 Series I L27 (1992-1994 SE,SLE, SSE) & Series II L36 (1995-1999 SE, SSE, SLE) and common problems for the Series I and II L67 (all supercharged models 92-99) Including Olds 88's, Olds LSS's and Buick Lesabres Please use General Chat for non-mechanical issues, and Performance and Brainstorming for improvements.

Engine tapping...?

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Old Dec 29, 2006 | 03:43 PM
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Default Engine tapping...?

Whenever I start my parent'* 96 SE (home for break), for maybe the first 30 seconds I hear this rattling, kind of tapping noise from the engine. I'm REALLY sorry I can't be more specific, but I don't know how else to describe it! Just, uh, tapping. It'* very strange, AND the check engine light has been on for the past few days, so I'm figuring something'* going to go wrong really soon...
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Old Dec 29, 2006 | 03:44 PM
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Crap I ALWAYS post on the wrong board, this should totally be in mechanical 96-99
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Old Dec 29, 2006 | 03:47 PM
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Next time you hear it, pop the hood and feel the evap purge solonoid bolted to a bracket on your front valve cover. You'll need the engine cover off in advance.

In cold weather the evap purge is much more obvious, and we get countless reports of mysterious ticking. It'* normal for it to go through a purge cycle on startup.

Make sure that'* the sound (you'll feel it), or see if it'* actually something else.
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Old Dec 29, 2006 | 03:50 PM
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For the record, the solonoid on the 92-95 cars is on the evap canister under the airbox. On 96-current, it'* where I mentioned in the post above.
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Old Dec 29, 2006 | 07:27 PM
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Does the tapping kinda go along with the speed of the engine? If so, it might just be a lifter that takes a few seconds to pump up with oil before it operates quietly. That would be pretty common and nothing to worry about at all. Still, check your oil to make sure the level is up. Low oil level can cause all kinds of valve train noises.
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Old Dec 29, 2006 | 10:28 PM
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I'd inspect the harmonic balancer (crankshaft pulley). See if the rubber on its face is in good shape. When they go bad, the rubber may look torn up and cause a noise. This one tends to happen at idle but go away with RPM
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Old Dec 29, 2006 | 10:35 PM
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Get it scanned & let'* see what the code is. The sooner you get it done the better, tow trucks are expensive.
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Old Dec 29, 2006 | 10:38 PM
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Originally Posted by F14CRAZY
I'd inspect the harmonic balancer (crankshaft pulley). See if the rubber on its face is in good shape. When they go bad, the rubber may look torn up and cause a noise. This one tends to happen at idle but go away with RPM
Failing harmonic balancers don't 'tap'. They CLATTER horribly. Iron on Iron. And the sound does not go away based on temperature or time.
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Old Dec 30, 2006 | 12:01 AM
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Originally Posted by willwren
Originally Posted by F14CRAZY
I'd inspect the harmonic balancer (crankshaft pulley). See if the rubber on its face is in good shape. When they go bad, the rubber may look torn up and cause a noise. This one tends to happen at idle but go away with RPM
Failing harmonic balancers don't 'tap'. They CLATTER horribly. Iron on Iron. And the sound does not go away based on temperature or time.
Yea that happened to me, not good, definitely not the balancer if its just tapping. Oh the flashbacks...Horrible Clattering, AHHH!
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Old Dec 30, 2006 | 01:58 AM
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I agree a HB is more or a "clatter" than a "tap" but we cannot hear this engine over a message board (no sound or vid clip ), and the fact that people describe sounds differently than others. Just a possibility I wanted to put out there.
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