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post #1 of (permalink) Old 02-22-2005, 05:54 AM
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Piston slap

Can so one tell me about Piston slap? I was told that was what my problem is in the #2cyl. It's not to bad yet just a funney sound when rev up to about 2700 last just for sec. then gone.
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post #2 of (permalink) Old 02-22-2005, 08:09 AM
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Re: Piston slap

Well not sure about piston slap in a 258 but,,, back in 80/81 when the Pontiac 4 banger piece of &*^$%# was used in the Jeep (until fixed later on by factory), we had piston slap galore. The dealer fix was to pull the pistons and have them knurled [img]images/graemlins/bag.gif[/img]. Yes that was the fix and I'm ashamed to say that [img]images/graemlins/wall.gif[/img]

The 1st thing I would do is pull the pan and check the piston skirts, you probably have one that is cracked or broken off. This is an occurrence that can and will happen by lugging the motor if you have high gears and big tires and use it over a long period of time that way.

I found #5 and #6 bad on a my 87 a few years back when I had the 307 gearing and 32" tires. I knew this was a problem but did it any way [img]images/graemlins/grin.gif[/img] He He #5 was broken off all the way up below the wrist pin and still ran OK. [img]images/graemlins/thud.gif[/img] But it slapped like crazy [img]images/graemlins/cussing.gif[/img]
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post #3 of (permalink) Old 02-22-2005, 09:32 AM
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Re: Piston slap

Piston slap is usually a wear problem, and not of great importance until it gets really bad. If it goes away within a few minutes of cold start, it's nothing to worry about. If it comes in and then goes away, even if the engine is warm, it's probably not piston slap.

And by the way, knurling the piston isn't necessarily a substandard treatment. The grooves left by the knurling hold oil, and piston wear and drag can actually be less than before.
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post #4 of (permalink) Old 02-23-2005, 03:07 PM
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Re: Piston slap

I had a Ford 300 I6 that right after a rebuild had a little piston slap. We had the right pistons for the bore, but she was just a little noisy. We had the pistons knurled then fit them with a little bit of emery cloth. That was in '90 and that truck is still on the road. I talked to the wife of the guy that bought that '78 from me and she told me that the "[email protected] thing just won't die!".
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