PISTON SLAP IS EXPECTED??? - MustangForums.com

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PISTON SLAP IS EXPECTED???

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Old 09-12-2018, 05:34 PM
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Sputnik775
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Default PISTON SLAP IS EXPECTED???

So I speaking with a service advisor at Ford in Austin TX regarding issues with a GT350. His comment was that Ford is issuing or issued a owner memo saying some piston slap may be audible and is normal. This is from 9/11/17. Can any of the gt350 owners confirm that.. Thanks!
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Old 09-13-2018, 01:30 PM
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Derf00
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They don't refer to it as piston slap but this is probably what you're referring to.


https://ford.oemdtc.com/1622/piston-...-mustang-gt350

"SSM 46173 – Some 2016-2017
GT350 GT350
Mustangs Might Exhibit Piston Rattle From Idle To 3000 RPM

Some 2016-2017
Mustang Mustang
GT350 GT350
equipped with the 5.2L
engine engine
may exhibit a rattle or rapping type sound during cold operation at light loads and speeds from Idle- 3000 RPM.

The noise will be most noticeable during light acceleration in the 1500-3000 RPM range and may also be noticeable in the 800-1200 RPM range with neutral throttle blips.

This sound is caused by the piston motion in the cylinder bore.

This is an inherent characteristic of the forged aluminum pistons utilized in this high performance
engine engine
.

Once the
engine engine
reaches operating temperature the noise will diminish, although it may still be noticeable even when fully warm.

There are no durability concerns with this sound."

The characteristic is because of the aluminum pistons, they expand as they heat up. If the pistons fit snug like traditional pistons when cold, as they expanded from warming up, you would have too much friction and just burn up the cylinders.

Anyways, I guess Chevy had the same issue in models that used aluminum pistons. Was never a big long term deal.

Last edited by Derf00; 09-19-2018 at 01:43 PM.
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Old 09-16-2018, 05:53 PM
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Sputnik775
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Good to know, Thanks!
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Old 09-18-2018, 01:53 PM
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Andy13186
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Im pretty sure this is also exactly what the 2018 5.0 "tapping" noise while cold at idle is.

Car starts and sounds fine then idle goes to normal and I can hear a tapping from the lower end of the engine I have some videos of it. It doesnt happen when warm and goes away completely when warm.

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