engine knock in 2008 LS3
Team Owner
Joined: Jul 2012
Posts: 34,479
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From: Central PA. - - My AR15 identifies as a muzzleloader
I believe in the Beer Fairy
So, closer fitting bearings and pistons isn't going to fix the problem? I'm not sure how else you figure on fixing his problem. You have another way to resolve it? I'd say I'm all ears, but, I stuck in pistons and bearings... amongst other things...
Tech Contributor
Joined: Oct 1999
Posts: 41,058
Likes: 9,817
From: Charlotte, NC (formerly Endicott, NY)
Piston slap is common on LS1 and LS6 engines and varies with oil temp. Both my LS1 and LS6 had piston slap that would start a moment or two after the engine fired and would last until the OIL Temp (not Coolant Temp) reached the 110 to 120 range. Most of the other LS engines I heard warming up at the track did the same. Here is a video take a couple of years ago of a buddies 02 Z06 idling. My LS1 and LS6 and a lot of others had the exact sound.
Since then the car has seen lots of track days and miles and the engine is going strong. It makes a noise, the noise just is and doesn't mean the engine is broken so you don't want to fix something that isn't broken. My LS7 didn't make any noise and the valve dropped and killed the engine. The new LS7 doesn't make any noise either. I don't think any other LS3 or LS7 engines at the track when I have been there ever had any piston slap.
Bill
Since then the car has seen lots of track days and miles and the engine is going strong. It makes a noise, the noise just is and doesn't mean the engine is broken so you don't want to fix something that isn't broken. My LS7 didn't make any noise and the valve dropped and killed the engine. The new LS7 doesn't make any noise either. I don't think any other LS3 or LS7 engines at the track when I have been there ever had any piston slap.
Bill
Last edited by Bill Dearborn; Dec 13, 2012 at 03:45 PM.
Team Owner
Joined: Sep 2003
Posts: 43,084
Likes: 33
From: Raleigh / Rolesville NC
again Normal.
If you dont like the noise run 10-w30 oil, let the engine warm up or put on LTs and free flowing exhaust. You wont hear the SBC piston slap
Putting in a 3 qt acqu-sump with a manual switch can help some what to prelub the block.
If you dont like the noise run 10-w30 oil, let the engine warm up or put on LTs and free flowing exhaust. You wont hear the SBC piston slap
Putting in a 3 qt acqu-sump with a manual switch can help some what to prelub the block.
Drifting
Joined: Jul 2003
Posts: 1,647
Likes: 2
From: Peoples Republik of Kalifornia Ka
Piston slap is not normal. Using different oil will do nothing to fix the problem. If you used different oil and the sound went away you didn't have piston slap to begin with.If piston slap is normal what do you call engines that don't have it? My 2000FRC had piston slap. I couldn't stand it. I had a 04 LS6 swap and now I don't have the slap anymore. My 05 Silverado with 80,000 miles doesn't have it.
NORMAL...HARDLY
NORMAL...HARDLY
Team Owner
Joined: Sep 2003
Posts: 43,084
Likes: 33
From: Raleigh / Rolesville NC
For SBC piston slap is normal
start any SBC especially trucks there is piston slap. Most ppl just dont hear it.
my 04 silverado has it. I was a Cheby dealership last week and cranked over a new 2012 1500 and a Suburban. both had piston slap.
Is it a good thing? no not really. loose fitting piston tolerances. but all within OEM specs.
start any SBC especially trucks there is piston slap. Most ppl just dont hear it.
my 04 silverado has it. I was a Cheby dealership last week and cranked over a new 2012 1500 and a Suburban. both had piston slap.
Is it a good thing? no not really. loose fitting piston tolerances. but all within OEM specs.
