Rchumsae

I know this topic has been talked about and talked about, i am paranoid; every little sound i hear needs an explanation. I recently bought my car so it still has the 90 day warranty which will cover everything but the clutch. Just like many other members on this forum and people i know, my motor makes a mild "knocking" sound especially when unter initial load (like when i tach it up a bit and quickly let off). This noise bothers me beacuse i know kids with LS1's that knock ALL THE TIME and i dont want mine to get worse. The guy at the dealership obviosly told me that this sound was normal, i just dont want this to cause premature wear and **** up my motor in ANY way. When the motors gets to warm operating temps. its fine, and i love it. But what would you guys do? what can fix this problem? should i even worry about it?!? Thanks a lot, and sorry to keep posting tired subjects.

01whitez28

I get a knocking sound when I'm in lower RPMs. Usually right after I shift. I put octane booster in my tank right before I fill it up and that seems to help a little bit.
You probably need a tune if you're running lean like I am. My car is %100 stock besides the wheels and shifter btw. I'm not going to tune it until I do some power mods.

VoodooWS6

I have the same issue! Dony worry about it, LS1's are a bit looser than your normal engine. It should not wear anything and you should get great life out of your engine. The dealer told me the same story, so I will just deal with it until I have a problem and get a stroker!

jaberwaki

aaahhhh you actually said alot....
there is a differance between the ls1 tap and the cold start piston slap... sounds like you have the later of these...
the nasty ls1 tap is constandt and does not go away.. it stays and generally the car eats oil(keep a close eye on yours)
but if it only makes this noise at start up then chances are you have cold start piston slap... that is nothing to worry about...
that has to do with the fact that a high compression(anything over 10/1 cr) motor is just noisy by nature until it gets to its normal operating temp... if you've ever heard a REALLY high cr motor (14/1+) this sound is all the time and at any temp...
if it goes away as the car warms up i would not worry too much...
however i would not give her WOT while in the warm up prosses...
hope that helps.

jimmyblue

iTrader: (11)

Revving it up unloaded is the specific behavior that
GM blames for high oil consumption, the unloaded
piston flopping around in the bore or some such.
Later models got tighter fitting, coated pistons.
But you shouldn't do that, really. Whether or not
you believe the story.

Rchumsae

okay, sounds good, thanks a lot guys

zamboxl

iTrader: (1)

yea i got the same problem only thing is mine doesnt go away after warm up it stays there the whole time specially betwen 15-23k rpm before wot the car pings/knocks like crasy if i give it gas so i cruse nice and slow up to wot or just down shift, speed up then upshift to get trought the turbulant rpm range; and yes the car does burn a **** load an i mean a **** load of oil when it has that condition. I actually took my engine apart (well working on it atleast) to see if i can fix theat problem somehow dunno how and because of some other internale noise

The Kiss Guy

My Hawk is being torn down next week for piston slap. 2 oil consumption tests show 1 quart low after 1,800 and today's was just over a quart in 1,300 miles. They were going to do a few more rounds but decided to go ahead and fix it now to help me keep from putting miles on the car for nothing. So next week, she'll be in ICU.

I heard it was more common in the M6's....but I have an A4. Of course one hour on the dyno last week probably helped too...lol.

KrazyDan

the tap seems to be what ive got and my car eats oil what is that problem? now youve got me worried. im still under warrenty til augusy though

zombie1

I have got the piston slap and tapping under load sometimes piston slap not that worried and the tapping is the crappy gas I get sometimes so I just fill half the tank with 101 and half 93 and then all is good....except my wallet! But I use no oil!

pwrtrip75

iTrader: (8)

ive noticed also, with headers, and especially a larger cam. the headers are much thinner wall than the factory manifolds. so they dont deaden much sound. you can almost hear when the exhaust valve opens and the gas is let out. its very a very faint sound, not everyone hears it, but if your paranoid you will. its more of a light tinny tapping sound. common with most modified vehicles running headers.

santino04

Yeah everyone pretty much has the cold slap. As far as being paranoid and being over dramatic let me give you an example. People make it sounds worse than it is by saying piston slap or the piston is flopping around inside the bore. So you automatically think of violent slapping or flopping when that just isnt the case, were talkin about a piston here moving up and down in tolerances about as big as a human hair, which is pretty damn tight! There is no chance of violent flopping or slapping in anyway unless the bore was made to big or is worn out totally, which in turn is true piston slap that is heard constant. When we talk its built as a loose enigne that is correct and in order to make more power you have to eliminate friction which GM did, and a great job at it without sacraficing reliability! As far as reliabilty and performance of these engines, they are one of the most if not the best advanced small block built today, and keep getting better. These motors are capable of handle up to 800 horses! They have also been used in many long duration races across the world, most notibly ASA Racing whose drivers have logged over 270,000 miles on everyone of 300 engines they ordered from GM. Dont Worry too much and happy moddin!

TX_SS

iTrader: (4)

i dont notice it..at all..no ticking noises...only if itz cold start..and it goes away in 2 or 3 mins..maybe 5 tops...but my engine purrrs like a cat~

The Kiss Guy

I don't care what anyone says is normal, when I lose 1 1/4 quarts of oil in 1,400 miles, something is wrong. They checked it Wednesday and today I checked and it's down almost a 1/2 quart already. I look forward to getting my pistons coated, reringed and matched for the cylinders.

XuhQshinR

So far since they replaced all 8 of my pistons and rings and had them each fitted it has been good (knock on wood)!

The replacement pistons were the new design for the LS6 #88984245 and have the anti scuff surface per the GM rep.

The ring sets were the new "napier" type scraper #88984247

They sent the block and pistons/rings out to a performance machine shop to have them fitted.

As I said, so far so good. I just picked it up from the Dealers Body shop tonight where they replced the roof for having bubbles in the paint. (the part of the roof that is usually painted black) It seems they used a urethane during production of the 99-2002 models that eventually causes the paint to seperate from the roof. It takes some time for it to become noticable unless you look for it. There is a TSB on it. Posted in the "Appearance" portion of LS1TECH.

DO NOT LET THEM JUST SAND AND PAINT IT!

The TSB calls for the roof panel to be removed and replaced. If all they do is sand and paint it will eventually come back.

I have to say it looks like they did a pretty good job but I will be able to check it out better when the sun comes out full bore!

Good luck with getting your issues resolved.

jaberwaki

this problem is usually due to bad piston rings ,poor assebly of them , could be valve stem o rings, could also be cylinder wall scored....ect ect ect
any of these can cause a tapping noise and oil consumption....

dont trust ANY service tech that tells you its normal to consume 1-2 quarts of oil every 3000..... its not...

zamboxl

iTrader: (1)

yep thats why i finally desided to rip my engine apart, and see what the hell is wrong with it and replace any worn part's i could get to. iam in the middle of doing this the wrk is hard long and slow, hehe to bad this is and engine not something else, but hey i'll see how the car runs when iam done. Hopefully the noise will be gone along with the 1-2 quarts of oil that now go missing every 3k miles. If not then i'll know i screwed up and spend another load of $ and take it to a profesional.

By the way you guys think it to be worth it to change the pistons to some high peroformance one's or something?

The Kiss Guy

Just talked to service, he said to bring it Monday morning. Not only are they reringing the pistons and checking tolerances, but also installing some kind of baffle in the intake to keep the oil out. So it looks like I may not need a catch can afterall.

web guy

Tons of info out there about the cold start knock or piston slap problem. http://www.gmproblems.com or www.pistonslap.com I'm having the same problem and it's driving me nuts. Check the other forums here, there's a lot of posts on this subject.