Piston Slap Poll

[scd603]

I have a 2017 and the engine was replaced under warranty last year due to oil consumption. The good news is that the oil issue is gone with the new gen 2 engine. However, the new engine has piston slap in 2k-3k range (just like the original one). It only happens until the engine warms up. I know Ford has said this is normal for this engine. I'm curious how many GT350 owners have piston slap.

BTW, maybe you don't have it and haven't heard of it. It is a rattling type noise when under acceleration.

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[Mustangford289]

All motors with forged pistons will make some piston noise....customers complaining is exactly why no manufacturers like to use forged pistons....this is why real car guys can't have nice things...

 

[UnhandledException]

My GT350 has done the piston slap since brand new till now 77k miles. I dont agree that forged pistons do this. Neither my ZR1 nor GT3RS have any piston slap. RS revs to 9000, has an insanely high compression ratio and does not burn a drop of oil regardless of style of driving. GT350 burns oil all the time. Have piston slap. Have tick tick tick typewriter tick (since brand new). Not saying they are harmful to the engine but its not something I have ever observed in any cars I have owned or driven. I have had the S65 Engine from BMW in my M3 that was a V8 revving to 8400 rpm with forged pistons. I have had no piston slap or 2 different M5s I owned or other F80 M3s I owned.

I think its due to quality of material. Tolerances in engine design and manufacture. Lack of equipment and labor for more precision. There is a reason why this car costs less than most mid quality SUVs but it has the performance it does. You get what you pay for.

 

[ecoboost321]

My GT350 has done the piston slap since brand new till now 77k miles. I dont agree that forged pistons do this. Neither my ZR1 nor GT3RS have any piston slap. RS revs to 9000, has an insanely high compression ratio and does not burn a drop of oil regardless of style of driving. GT350 burns oil all the time. Have piston slap. Have tick tick tick typewriter tick (since brand new). Not saying they are harmful to the engine but its not something I have ever observed in any cars I have owned or driven. I have had the S65 Engine from BMW in my M3 that was a V8 revving to 8400 rpm with forged pistons. I have had no piston slap or 2 different M5s I owned or other F80 M3s I owned.

I think its due to quality of material. Tolerances in engine design and manufacture. Lack of equipment and labor for more precision. There is a reason why this car costs less than most mid quality SUVs but it has the performance it does. You get what you pay for.

It would be interesting to have a poll of owners who have had an aftermarket engine rebuild done and their experience with any extraneous noises as well as piston slap.

 

[stanglife]

I've built a Boss 302 motor from the block up. Measured each 4032 piston and each bore - balancing included getting the pistons in the correct bore in order to get closest to even clearance between them all. These pistons/rods/block/crank came directly from Ford Racing and everything measured perfectly....it's been years but I think clearance was .0035 I put this engine in a Fox Body, so very little sound deadening going on there. Yes, it had piston slap when it was cold and very light throttle pressure. Warmed up, 100% goes away. Same engine in an S550, you might have trouble hearing it. I think many many cars "have" it but many mask it better.

The term piston slap actually sounds much worse than the actual problem "usually" is. There have been vehicles that have it to the degree where it never goes away and ultimately causes damage. Most performance engines have these short skirted pistons and they are going to rock a little in the bore until the material expands.

I've never heard this from anyone, so it's my made up logic...but similar to when you tell the doctor that it hurts when you do xyz...and the doctor says well don't do xyz... I try not to drive around with super light throttle when the engine is cold but I don't beat on it, either. Even though I can barely hear anything in my 2020 - I give it enough throttle to both 1 - get out of that range where you can hear the piston rocking and 2 - it just gets the temps up a little faster and grows them pistons.

 

[stanglife]

PS, I have no idea what the tick tick is that people refer to. I head injectors firing but that's about it.

 

[Mrhavasu]

2020 and no slap or oil burn.

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