Piston Slap
Instructor
Joined: Jun 2006
Posts: 211
Likes: 2
From: Glendale CA
Ive tried alot of the suggestions found on the forum,
-Different oil filters, higher flow, K&N etc, No change
-10w30 instead of 5w30 Mbil 1, No change
-Lucas oil additive, No change
So now I just try to ignore it. It is embarrasing, and is not what I expected my Vette to sound like. But many of them have it and doesent seem to be a real issue, other than sounds horrible..
-Different oil filters, higher flow, K&N etc, No change
-10w30 instead of 5w30 Mbil 1, No change
-Lucas oil additive, No change
So now I just try to ignore it. It is embarrasing, and is not what I expected my Vette to sound like. But many of them have it and doesent seem to be a real issue, other than sounds horrible..
Team Owner
Joined: Jan 2004
Posts: 22,185
Likes: 65
From: NJ
Originally Posted by DADEO1
My 99 does the same until it warms up.
I have been told that they are like a Harley, built to such tight tolerances they make noise until up to operating temps.
I have been told that they are like a Harley, built to such tight tolerances they make noise until up to operating temps.
Most new GM LS based engine do it. Its a result of the type of hyperutectic pistons they use combined with the pistons short skirt. Once the engine gets a few miles on it and a carbon ring starts to build up at the top of the cylinder, it causes the cold piston to "rock" in the cylinder when it reaches the top of its travel, causing the knocking sound. As soon as the piston warms up and starts to fit to the cylinder (a common occurrence with hyperutectic pistons) it goes away.
GM claims its harmless and only a customer annoyance issue. I have yet to hear of an engine failure due to this condition.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Race Director
Joined: Sep 2004
Posts: 17,786
Likes: 4
From: Redsox, Pats, Celts & Bruins !!! Redsox Nation !!!
St. Jude Donor '06-'07-'08-'09-'10-'11-'12
Le Mans Master
Joined: Dec 2003
Posts: 5,561
Likes: 448
From: Atlanta metro Ga.
Here's an interesting approach;
The folks over at HP Tuners have built an option to reduce piston slap via manipulating ignition timing until a certain engine temperature is obtained.
The folks over at HP Tuners have built an option to reduce piston slap via manipulating ignition timing until a certain engine temperature is obtained.
Race Director
Joined: Nov 2005
Posts: 14,553
Likes: 1,549
From: Supporting the Corvette Community at Abel Chevrolet in Rio Vista, CA 707-374-6317 Ext.123
St. Jude Donor '08
Originally Posted by screw991le
These a-holes that created that website should be "piston slapped" in their Gm hating faces. ......Seriously, they should get a life.
Melting Slicks
Joined: Jun 2004
Posts: 3,439
Likes: 6
From: Newark, DE
St. Jude Donor '06
Originally Posted by TroutFisher
Ive tried alot of the suggestions found on the forum,
-Different oil filters, higher flow, K&N etc, No change
-10w30 instead of 5w30 Mbil 1, No change
-Lucas oil additive, No change
-Different oil filters, higher flow, K&N etc, No change
-10w30 instead of 5w30 Mbil 1, No change
-Lucas oil additive, No change
FWIW, higher flowing filters will quiet down the cold-startup valvetrain chatter (e.g., K&N or Baldwin B31). But you never want to use the Lucas additive!
Drifting
Joined: Dec 2005
Posts: 1,720
Likes: 3
From: East Hampton CT
Originally Posted by Dan_the_C5_Man
Here's an interesting approach;
The folks over at HP Tuners have built an option to reduce piston slap via manipulating ignition timing until a certain engine temperature is obtained.
The folks over at HP Tuners have built an option to reduce piston slap via manipulating ignition timing until a certain engine temperature is obtained.
Yep, look at my posts above...there are features in the tuning software that will reduce/eliminate this.
Race Director
Joined: Sep 2004
Posts: 17,786
Likes: 4
From: Redsox, Pats, Celts & Bruins !!! Redsox Nation !!!
St. Jude Donor '06-'07-'08-'09-'10-'11-'12
Originally Posted by RichieRichZ06
These a-holes that created that website should be "piston slapped" in their Gm hating faces. ......Seriously, they should get a life.
That site has been out for around 10 years, it still gets a ton of hits. But I have to say, by 97, 99 Camaros both had slap, My 00 Vette and 03 Trail Blazer both have slap. So somethings up. I have just learned ti live with it. But sometimes it sounds like a diesel
Safety Car
Joined: Oct 2004
Posts: 4,816
Likes: 132
From: Plano TX
Pissed me off when I first bought my car too. Very annoying but now I live with it and don't notice it much.. Try installing Headers and a Borla Stinger exhaust system.. This is the best remedy for piston slap
Drifting
Joined: Oct 2004
Posts: 1,345
Likes: 3
From: Mesa Arizona
Originally Posted by David426
Pissed me off when I first bought my car too. Very annoying but now I live with it and don't notice it much.. Try installing Headers and a Borla Stinger exhaust system.. This is the best remedy for piston slap