JoeMack

I know that this subject has been beat to death, so be easy on me. I'm just looking for some advice. It looks like that I will be able to get GM to replace my pistons (I was hoping for an engine) due to piston slap. Oops, I’m sorry, "cold start knock". I have heard conflicting stories about the benefit of having this done. Most are saying that the odds are good that after an initial period of the elimination of the knock, it will return. I am also very concerned about my 14k mile engine being torn apart and the damage that can occur to my car during the work, by a dealership service department that I know nothing about. This dealership (where I originally purchased the car) and is a three hour drive away, is the only one that is willing to at least make an attempt at a repair. I was given the extended engine warranty but for some reason that little piece of paper just doesn’t do the job of quieting down my engine. Do you guys think that it might be worth the trouble or do like most everyone else and live with it?

Thanks

ss00

How bad is the noise? Is it noisy at idle? At certain RMS's only? Does it go away when the engine reaches full operating temperature? Has the noise gotten progressively worse over time? You could live with it for now if its not too bad, and pursue a repair under the extended engine warranty if it gets worse later on.

99 z28 Haas

does the slap not go away when the car is warmed up?? if i just turn my car on and drive ill get some slap but it goes away when my car reaches operating temp. if it does go away after warmed up i think what you are doing is totally unecessary. its very rare that the slap causes REAL problems. so if the slap does go away......i say, deal with it for the first 2 minutes your car is on. if it doesnt go away and is some pretty serious stuff, then i guess go ahead with what you plan on doing. i know i would be feeling the same way about lettin a dealership rip into my 14k engine.......let me know how it goes

96Z28/93TA

I would just live with it, they all do it. It wont hurt the durability or reliablity of the engine. the 3100 engines have the same problem, we replace all 6 pistons and it usually just barely helps the noise. we havent done any LS1s yet but I would leave it alone unless its a bearing noise.

BlackZ28Camaro

I had my piston replaced at the dealer in my 02 camaro. The knocking was reduced by about half. But its still there all the time. Even after the car warms up. I only had 22,000 miles on my car when they replaced the pistons, and I now have 23,000. So I dont know if it is going to get worse or not. And the dealer and GM says the knocking is at an acceptable level now.

I dont know of any acceptable knocking an engine can make. Im thinking about rebuilding my engine my self or going to court against GM.

There piston slap is a wide spread problem. Also the only difference in the replacement piston is a thicker TEFLON coating on the piston skirts.

JoeMack

The slap begins about a minute after cold start up. Within a mile of driving it, it seems to go away. Now this in itself, I would be able to handle. My problem is, when after less then 5 minutes after I shut it off (completly warmed up) and then re-start, the slap begins again. Again, after less then a mile of driving, it will go away. I know to some people it sounds like I'm getting carried away with such a minor case of the slap (I wonder if penicillin might work?) but I feel that this is a design flaw that GM is calling normal and we should not so readilly except. I am just worried that if I agree to the pistons being replaced I might be making matters worse.

AL SS590 M6

I wouldn't let them touch it if the noise goes away that quick.