I have already a little slapping i my engine ( 14000 Miles ) and i´m a little worried that it will be worse... :(
I have read on som other sites that it is a problem that will only get worse and louder, and in some cases wear my engine down.
That made my worried, and i made this poll to see how many of you guys that also have this problem.
Please, vote... :blueangel:

 

Mine does it for a short while, then it goes away. Common with forged pistons. My Camaro did it back when it had forged pistons in it. My Thunderbird does it too, especially in the Winter. (yep, it has forged pistons too because of the supercharger). I wouldn't be too concerned about it.

 

My 2000 did it when it was cold for a minute or so. Dealer said not to worry. :cheers:

MRR

 

Sure it's piston slap? I know alot of LS1's have this problem, but could also just be a lifter bleeding down? I think this is what I have (which is no big deal) :) based on the fact that when I start the car cold, I get a knocking sound. Will continue for a couple minutes if I let it just idle. If I rev it to about 2000-2500 rpm (gets some oil flowing to the lifters) and hold it there for just a few seconds, it goes away away immediately. I also get it sometimes on a hot engine after it sits a few minutes. Been that way since new, 27k miles later it hasn't gotten any worse so I don't worry about it :)

 

Piston slap = a piston to cylinder wall clearance that is over tollerence. Pistons

Also causes blow by oil consumption. Are you using oil?

 

Hi.
I am quite sure that it isn´t a lifter bleeding down, because the noice is deep and "hollow". The noice is still there after revving to 1500, it must be completly warm before it goes away.

Yes i´m burning oil, i don´t know exactly how much yet, i´m not a hard driver but i need do fill it up a little between the changes.
Here they use Mobil One 0w-40, is this oil perhaps not thick enough?
I find it a little strange...after just ONE year of use and 14k Miles...! :confused:
(i have a model 1999 with 1 reg.date April 2001)

JE.

 

Does the engine sounds ever-so-slightly like a diesel? I don't know much about the vette engine, but I'd find it extremely hard to believe that the factory put pistons in there are not hypereutetic.

Forged pistons can rattle, but the days of OEMs putting pistons in that have such a large wall clearance are long gone. The hypers are used because they have extremely tight piston to wall clearance and dont expand very much. Forged expand and thus need the clearance. Only race engines should have piston rattle and you'll likely not hear that over a race exhaust.

OEMs use the newer hypereutectic pistons because they need something called the "crevice volume" of the piston-to-wall down the rings to be as small as possible as it is a major contributor of emissions.

I don't want to cause panic, but the only other thing I can think of besides actual piston rattle is a bad bearing. A spun or damaged rod or main bearing will cause a similar sound, but usually in the case of the bearing it's loud or gets loud relatively quick. Bearings if they went bad usually don't last long before it's so loud it's obvious the engine has something bad wrong with it.

You might consider having your oil analyzed.

Best of luck,

PLT