formula87

iTrader: (2)

I am new to the forums but have owned my SS since new. Has always had a knock when cold goes away after warms up. lifter / piston slap? Motor has no internal mods. I am a mngr at the same Chevy dealer were I picked it up and still work there, was told it was piston slap, by the techs so I just did't think any more of it but after 7 years and 30k it still buggs me any suggestions? I have heard this from cust who have bought new trucks mostly never any vette or Fbody cust.....

I know all of you guys have heard this before but could't find an old thread on this subject..


Also under hard accell it "pings or spark knocks" I have an old hypertech tuner that I used on the car that I got back in 2000 but it never seemed to make that much perf diff....I know there are tons of tuners out there now for these mtrs should I trash the hyper tech?

thecorrectformula

Piston Slap. It's a normal GM engine occurance. Nothing to worry about. It's only considered a nucence problem. Sorry my spelling sucks

formula87

iTrader: (2)

Thats what I figured I have had it on the road course and the strip and never had a problem with the noise getting any worse. I was also told it was carbon build up on the tops of the pistons ???????????? and that was what GM told us to tell all our cust????
who had the same noise.......

warpwr

When mine was new (02) the dealer found preliminary service bulletin #00150 for piston replacement. If you work at the dealer, you could probably find the same one. Might be too late now though.
Anyway, I told them I'd rather have the piston slap than to have them take my engine apart.
They were going to put in pistons with longer skirts to stop the slap according to what I was told at the time.
It still slaps and you know what, it is probably the strongest, best running, most potent, good gas mileage factory engine I've ever owned.

87gnx

iTrader: (3)

Carbon build up on the pistons has nothing to do w/piston slap, but it might sound good to a customer.(??).I use Amsoil 5w/30 and it seems to help a bit, this is a common trait to our beloved LS1's. Check out my site at www.synthetic-oil-tech.com/1262175 if you like.

formula87

iTrader: (2)

sounding good to cust ? not necessarily, we had to replace some mtrs and the new one still made the noise this was mostly in the 99-2002 models. seems like GM fixed whatever it was.

I will check the site out.

firehawk618

iTrader: (14)

Mine does it too. But if i take the rpm's to 2k it stops and doesn't come back. If I keep it below 2k it will tap / knock till it's fully warm.

ULTIMATEORANGESS

iTrader: (4)

PS is normal. people just like to cry.

as far as your pinging goes remove that programming and see if that helps.

ghardester

Regarding the ping/spark knock. You are running only Premium fuel right? If so and you are still getting pre-ignition I would look into that. I wouldn't worry about a little normal LS1 engine noise though. Mine ticks like a sewing machine when cold.

boola1341

iTrader: (1)

i have the same problem coming from my engine.......even the pinging noise at wot. all i use is premium fuel. I'm thinking about getting a mail order tune or the handheld predator to see if that helps the pinging noise.

capn smokey

iTrader: (1)

Take off the programmer and see if the knocking still persists, and piston slap is pretty normal for ls1s. They corrected it in 02 I believe with a tighter piston ring clearance, but it has been proven not to affect performance or durability.

z06 mike

I have had two motors with the same problem i was told the same thing. They had too much clearence in the rod caps they were loose. Both ls1 motors 98 and 01.

HDNVALLEY

Just another example of fine GM design. They seem to have a knack for making a mostly good product but screwing up one thing to **** off customers. I had a Silveado with the 6.0 that you could hear piston slap from 100 yds away. The dealer tech even said something should be done but the GM service rep. would only offer a 100,000 mile warranty. It might not affect engine life but it PO'd me every time I started it so I traded the POS off. My Formula doesn't have it so I guess I got lucky on that one!!!

formula87

iTrader: (2)

Thanks for the info
That all the techs told me too at the Chevy dealership were I work I was just being a typical cust with a noise but the WOT sparknock or ping sound I was told it could be a sensor located under the intake????????? I was going to replace that when I get around to swaping out the intake and maybe a cam and LTs.

jed.only

iTrader: (9)

totally normal. thats a minor problem compared to the LS2 guys and their oil consumption. but a little slap is normal and everyone has it.

zuuhlsT/A

iTrader: (2)

It kinda freaked me out too when i first heard it. But thankfully I looked it up here and it put my worries at ease. Mine goes away after about 3 minutes. Gotta love this site!!

Omec

iTrader: (2)

ya man, i have a similair sound at WOT right around 6 grand. i had it dyno'd a little while back and its got a perfect A/F ratio all across the board. i started talking w/ another member in the maint section about it and he said he had found some loose o2 sensors. ive yet to look but could be somthing stupis as that or what im thinking mine is possibly the cat(s) braking up. mines only got 32,000 miles as well. i would take the tuner off. i had a super chips and it was only good for changing shift points. also have the piston slap/valve noise. lol was told by the dealer it was because i wasnt using mobil 1. that pissed me off having 6 ASE's and an associates from NEIT in automotive science. needless to say i didnt believe him. i dont mean to blow my own horn but geez, that was the stupidest thing they could have said. anyways bet ya 10bucks mine is louder than yours .