Piston slap( HELP PLEASE)

player4lifeov

New Member
Mar 22, 2006
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California
I think my car has what you guys call piston slap but not very sure because the noise is heard when the car is warm and it only happens at about 2300 rpms. i went to my mechanic and when he was going through each cylinder he deactivated one of them by pulling something off and the noise went away. When he put it back the noise came back. What are the causes of this whole piston slap? Is it fixable and how much would it cost? Please help!!:(
 
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that's not piston slap. piston slap is when the diameter of the piston is worn or the cylinder bore is worn to a point where the piston no long fits snug. the piston then bounces back and forth in the cylinder while moving up and down. unpligging the fuel injector or spark plug will not make the problem go away. the piston is still going to be moving. my guess is that either the fuel injector or spark plug is the problem. but i can't tell for sure without more info.
 
You would notice piston slap even if your mechanic unplugged the coil or injector. This is because the piston is still moving up and down yadda yadda yadda. Chances are is a noisy injector or a bad plug. Change the plugs and throw some seafoam or techron in your gas tank.

Good luck
-Scott
 
Quite a few cars have noticable piston slap, Chevy's included... lol.

But, like said it wont go away by unplugging an injector or cutting spark to that cylinder. That is more of a rod knock symptom, definatly get that checked out asap before its too late.

But, before we jump to conclusions, what does the noise sound like? How loud? Is it a knocking, ticking... so on.
 
Piston slap is not always caused by worn parts, and many cars suffer from it straight off the assembly line. Including many windsor 4.6 and 5.4 motors made in the late 90's. Ford was replacing engines for a while to fix it if the cars were under warranty. But like other have said, if what you had was piston slap, it wouldn't go away by disabling the fire to it.
 
From what I understand of piston slap it usually only occurs on higher milage engines and mainly on the 5.4 due to the longer stroke and the greater rod angle. What happens is the thrust side of the piston creates bore distortion which when the engine is cold will cause some piston slap until everything heats up and expands into place.

Ford added more iron to the 5.4 blocks in 2001 in order to reduce this effect.
 
It also has to do with different types of pistons aswell.

Certain types of pistons contract more than others when they cool, so when the engine is re-started they have a little room to "slap" around in untill they are warmed up again.