Dealer describes "Piston Slap" as a "Normal" characteristic of the 5.0 V8

[StangTime]

Received my Blackstone oil analysis last night. All looks good!

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[Cory S]

That pretty much eliminates piston slap unless they built them at the factory with bad clearances. Piston slap almost universally comes from thermal expansion and contraction of the pistons inside the less expanding/contracting bores.

My 2618's @ .0045" don't even slap LOL......

 

[Angrey]

My 2618's @ .0045" don't even slap LOL......

I don't notice much on mine either, but in order for the piston to "slap" it has to either start and/or end it's thermal cycle with excessive clearance to the bore.

If the pistons are hypereutectic, then that's only possible if the builder put them in with excessive gap.

 

[Cory S]

I don't notice much on mine either, but in order for the piston to "slap" it has to either start and/or end it's thermal cycle with excessive clearance to the bore.

If the pistons are hypereutectic, then that's only possible if the builder put them in with excessive gap.

Well, a 4032 is still forged construction, but requires usually no more than .003" max PTWC in most situations. Hypereutectic even less PTW, and can get away with as little as .0015".

I've heard real good slap many times where a builder throws in 4032's @ .0045" OOOPS........
Also seen 2618's with .007". Ouch...

 

[1MeanZ]

Not all piston slap is caused by the piston fitting the bore too loosely. In the GM applications it's the wrist pin bores in the pistons, not piston to cylinder bore clearance. When they are cold, the wrist pins are too snug in the pin bore which forcibly rocks the piston in the cylinder bore. Once the piston warms up and expands, the wrist pin bore opens and all is well. I'm not saying this is or isn't happening with the Coyote, simply pointing out that piston slap can have more than one root cause.

 

[Redmcguire]

Pistón slap in any application is not normal. Again Ford or the dealership is lying the groundwork to try and get out of any warranty work that require a new engine. I would get a second write from an independent mechanic or 2. That way you have your bases covered in case a catastrophic failure occurs.

I absolutely agree with AZlb5.0 on this. All the ford dealerships in your area that sell GTs, Shelby or Roush will know who the performance shop guys are... because when they have a problem they cannot solve, they call them too! They all know each other. Get the opinion of a third-party performance shop, get his opinion or even a recommendation to a master tech at a dealership in your area, take the recommendation and their findings to the dealership and hope they agree to investigate. If not, a lawyer with your performance shop findings should get things rolling along. An engine is cheaper than litigation and then an engine . Hang in there. I know it's daunting, time consuming and expensive, but you can't let them win... You deserve what you paid for.

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