Hey everyone, I just bought a 2001 WS6 M6 with 6k miles. I noticed that sometimes around 2k RPM's the car sound sorta like a deisel. The sound comes from the motor, it sorta sounds like tappits. The sound is very similar to the sound you get if you shift into forth at like 25mph. I'm sort of worried but I've have heard a rumor about something called piston slap??? is that common on LS1's? thanks in advance for any info>.....good thing the car's still under warranty!

 

oh ya, the sound seems to go away after about 10-15 minutes..

 

Sounds like piston slap man, does it do this at idle when the car is not up to operating temp? Go to www.pistonslap.com this is a very informative site. Good Luck man

WeS

 

Yah, sounds like piston slap to me. A lot of them do it, some worse than others. Interesting website.

 

its piston slap.my 35th sounds like it during cold start goes away during normal operating temp.

 

Definitely piston slap. Sorry to break it to you but GM will do nothing about it so your warranty isn't going to help.

 

Yup, Unit123 is kinda right chances are they won't fix it, but in my case they extended my warranty on the motor for 5years or 60,000mi...........Don't assume the dealer will give this to you though, I had to fight with them on this issue for a few weeks, mainly due to the fact the idiots said the couldn't hear it!!!!!! As any one with piston slap knows you can hear it clear as a bell (at least you can case you can)

 

yep sound to be da case. its eather that or for some odd reason your timming jumps outta wack.
i say you track down a good block and start building up a "fun" engine then when its done swap em out and investagate the probablem....
basically a good excuse to build up a ***** a giggles engine.
good luck man

 

FWIW, I've never heard of major engine troubles due to piston slap. I ran 11.5x's all day long on a 150shot of nitrous with no major concerns.

 

is there any trouble that comes with it?? Does the piston slap ruin the motor or will everything be ok? This really sucks, I'm gonna head down to the dealer right now!!

 

I think I read here or on another forum...this guy was having piston slap, and when he tore apart his engine he had dents in his piston and his valves were bent.

 

piston slap is bad. You can massage it with some good oil synthetic, but ultimately you want to fix the problem before it ruins your head and block. All it takes is a cracked piston to come apart and leave you with a rod out the block and tore up head. Thankfully used ls1 motors aren't all that bad.

Might be good time to save your nickels for a used block to build up or well, fix the issue. neither will be cheap.

Damage is probably already done, the idea is to control the damage before it spreads to having no core (block/head) i spose.

 

wow, i guess this can potencially be a huge problem. I called my dealer and they made an appointment for Thursday. They said if it is pretty severe, they'll have to tear down the motor and completely rebuild it, or else put in a new motor. What a pain in the neck. Thanks for all the help guys

 

What exactly happens when your engine has piston slap? Does the piston not seal well in the cylinder and the piston slaps the cylinder walls? Or do the valves tap the top of the pistons or what? I was just curious.
Thanks

 

Bingo. Over-bored cylinder. It happens when it's cold and disappears when at operating temp due to thermal expansion of the piston.

 

That's it? I got a 100k mile for mine. Can't say it still doesen't bother me though.

 

I gotta go listen to my car now. I always thought it was the belt tensioner, now I think it might be piston slap. I thought it was the tensioner because every time it move I heard a click......but damn, with piston slap and detonation how bad can I see the future of my 34,000 mile LS1 ?

 

always the opportunity for that stroker kit do it before it does you heh