Piston Slap
#22
TECH Fanatic
iTrader: (8)
you are kidding right?? Somone honestly wants you to blow your car up.. That "theory" holds true to diesel trucks especially with air brakes but NEVER just before a rev limiter or redline... if you ARE going to rev up the car to hold an idle...when its cold...I would NEVER go above 2000 rpms....and even that's a little much...1200-1400 is about all you would even rev it to if you want it to warm up faster but the smarter thing is to let it warm up in idle......
#23
I write checks with my mouth that my ass can't cash
iTrader: (7)
Join Date: Oct 2009
Posts: 948
Likes: 0
Received 0 Likes
on
0 Posts
lol alright funs over...no i never touch the gas until my car is almost completly warmned up...and i never give it WOT until its all the way warm...i was just having a little fun seeing what the comments would be.
#25
LS1Tech Administrator
iTrader: (3)
Join Date: Nov 2001
Location: Schiller Park, IL Member: #317
Posts: 32,364
Likes: 0
Received 1,795 Likes
on
1,279 Posts
I find the best way to clear up piston slap is to keep the pedal floored while starting the engine cold, so as soon as the motor is running you're at WOT. Then, I instantly shift into gear while keeping my foot on the brake and gas, doing a massive burnout through 2 gears. I then release the brake and stay at WOT coming out of my driveway all the way till it shifts to 3rd (about 100mph). If there is traffic in the way, I just drive on the sidewalk. That usually gets rid of any slapping!
#26
TECH Fanatic
iTrader: (8)
i find the best way to clear up piston slap is to keep the pedal floored while starting the engine cold, so as soon as the motor is running you're at wot. Then, i instantly shift into gear while keeping my foot on the brake and gas, doing a massive burnout through 2 gears. I then release the brake and stay at wot coming out of my driveway all the way till it shifts to 3rd (about 100mph). If there is traffic in the way, i just drive on the sidewalk. That usually gets rid of any slapping!
#30
LS1Tech Administrator
iTrader: (3)
Join Date: Nov 2001
Location: Schiller Park, IL Member: #317
Posts: 32,364
Likes: 0
Received 1,795 Likes
on
1,279 Posts
In my experiance, the '01-'02 cars usually slap louder and are more prone to the issue in the first place.
I beleive there was a piston or ring change made in 2001. I suppose this might have something to do with it.
I beleive there was a piston or ring change made in 2001. I suppose this might have something to do with it.
#31
TECH Regular
Join Date: Aug 2008
Location: Harrisonburg, Virginia
Posts: 421
Likes: 0
Received 0 Likes
on
0 Posts
I find the best way to clear up piston slap is to keep the pedal floored while starting the engine cold, so as soon as the motor is running you're at WOT. Then, I instantly shift into gear while keeping my foot on the brake and gas, doing a massive burnout through 2 gears. I then release the brake and stay at WOT coming out of my driveway all the way till it shifts to 3rd (about 100mph). If there is traffic in the way, I just drive on the sidewalk. That usually gets rid of any slapping!
#32
On The Tree
Join Date: Sep 2009
Location: Huntsville, AL
Posts: 197
Likes: 0
Received 0 Likes
on
0 Posts
#33
Teching In
Join Date: Dec 2009
Location: Dayton, Ohio
Posts: 22
Likes: 0
Received 0 Likes
on
0 Posts
Ahem, these engines won't start at WOT, the injectors are turned off! DUH!
My 98' WS6 has a hint of slap when cold, and none when warm. She has
127k on the origional motor. I just ignore it, and let her warm up to atleast 160 before taking off. My fathers LQ4 slaps, but only on VERY cold mornings.
#34
so is the culprit with piston slap the piston rings? and more comonly 01-02 cars?
wondering, i have a 02 crate in my car with 25k, dont get any, but its a relatively new engine.
wondering, i have a 02 crate in my car with 25k, dont get any, but its a relatively new engine.
#35
I thought GM changed the type of rings, TIGHTENED the cylinder tolerences and coated the piston skirts for 2001 -02's to prevent scuffing (due to tighter tolerences) due to the customer complaints? GM High Tech brought up these technical improvements in its mag back in the day. GM still maintained that the piston slap was a customer satisfaction issue rather than a durability issue, as far as they were concerned (yeah, limit warranty claims) yet they saw fit to make the already mentioned improvements! Some of the improvements were made to combat "ring flutter" (and resulting oil consumption). After 2000 I thought piston slap was not an issue?
#36
LS1Tech Administrator
iTrader: (3)
Join Date: Nov 2001
Location: Schiller Park, IL Member: #317
Posts: 32,364
Likes: 0
Received 1,795 Likes
on
1,279 Posts
#37
TECH Senior Member
iTrader: (8)
A little PS or CSK (cold start knock) as it is sometimes referred to hurts nothing in these motors. My 98 LS1 has none at all. My 196K 5.3 LM7 in the truck has had it since I bought at 87k and has no change in noise or oil consumption. It has always used about a qt. at 3k and never more and still runs like the day I bought it in 01.
It is caused by excessive piston to bore clearance causing the piston to rock until it heats and expands to fill the bore. Also these pistons. have short skirts to keep weight down and carbon builds on the skirt and makes it noisy. This why seafofam or a similiar treatment can help temporarily. Many forged pistons are also this noisey but with headers and aftermarket exhaust they never hear it or report it. I had a buddy with a Mopar 440 in a challenger built as hell and that thing was ugly sounding on cold start but could rape anything he wanted too when it counted......he ran it for years before we lost touch...It was the wristpin offset that made that car so noisy is my point.... DRIVE IT!!!
It is caused by excessive piston to bore clearance causing the piston to rock until it heats and expands to fill the bore. Also these pistons. have short skirts to keep weight down and carbon builds on the skirt and makes it noisy. This why seafofam or a similiar treatment can help temporarily. Many forged pistons are also this noisey but with headers and aftermarket exhaust they never hear it or report it. I had a buddy with a Mopar 440 in a challenger built as hell and that thing was ugly sounding on cold start but could rape anything he wanted too when it counted......he ran it for years before we lost touch...It was the wristpin offset that made that car so noisy is my point.... DRIVE IT!!!
#39
TECH Enthusiast
iTrader: (13)
Join Date: Feb 2007
Location: near rockford
Posts: 554
Likes: 0
Received 0 Likes
on
0 Posts
98 ws6 here. 81k miles NO piston slap whatsoever. I also rarely burn a drop of oil and I have full bolt ons. Thankfully I guess I got a good one since I heard 97-00 ls1s have more slap then newer cars however I hear more 2000+ cars having more slap then 2000 or less lol. Hell my buddies 04 gto has under 30k miles and is a slapper