LS1 piston slap, How much is too much?
10-09-2008, 06:35 AM
#1
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LS1 piston slap, How much is too much?
I get a fair amount of piston slap when cold in my 2003, and I was wondering how much damage does piston slap cause? I don't drive a lot, car only has 12K miles on it and I use ExxonMobil 93 octane. Is there a way to remove the carbon buildup? I had the dealership clean the injectors a few months ago, but I still get that slight knock until the engine hits 180 degrees, and once warmed up, I don't get the knock for the rest of the day. Only get it in the morning when engine is really cold! Any advice is welcome.
10-09-2008, 07:24 AM
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Melting Slicks
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St. Jude Donor '08-'09
piston slap has to do with excessive clearance between piston and cylinder wall. we're talking about thousandths and ten thousandths of an inch. as the piston expands the clearances decrease and the sound goes away. when you have piston slap at normal operating temps that will be the time to worry. I've had 3 LS motors and each one has had this problem. I just turn up the radio before I start the engine
10-09-2008, 08:01 AM
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St. Jude Donor '07-'08,-'13-'14, '16-'17
piston slap has to do with excessive clearance between piston and cylinder wall. we're talking about thousandths and ten thousandths of an inch. as the piston expands the clearances decrease and the sound goes away. when you have piston slap at normal operating temps that will be the time to worry. I've had 3 LS motors and each one has had this problem. I just turn up the radio before I start the engine
I think it's funny sounding when I run across one that doesn't do it...
Peace
Chip
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10-09-2008, 08:42 AM
#5
Drifting
Hi There:
The piston slap you hear is the carbon build up on the ring lands causing the pistons to rock. This sounds like valve tappet noise.Starting in the 2002 model year the pistons were teflon coated to eliminate this problem at start-up or cold temperature operation.I would run a few cans of this fuel injection cleaner.Its called BG 44K made by Bg Products Inc. since 1971.After a few cans of this most of the carbon will be reduced. The noise will go away. However it will return, one of the down sides of using high octane fuel. My 01 stock coupe with 15k does the same thing until warm up is completed. Another good fuel injection cleaner is Techron Plus. Bg 44K is only obtainable from dealers, formerly called mechanics injection cleaner. About $20. for 11 oz. can. I would not lose any sleep over this.
robsc501
The piston slap you hear is the carbon build up on the ring lands causing the pistons to rock. This sounds like valve tappet noise.Starting in the 2002 model year the pistons were teflon coated to eliminate this problem at start-up or cold temperature operation.I would run a few cans of this fuel injection cleaner.Its called BG 44K made by Bg Products Inc. since 1971.After a few cans of this most of the carbon will be reduced. The noise will go away. However it will return, one of the down sides of using high octane fuel. My 01 stock coupe with 15k does the same thing until warm up is completed. Another good fuel injection cleaner is Techron Plus. Bg 44K is only obtainable from dealers, formerly called mechanics injection cleaner. About $20. for 11 oz. can. I would not lose any sleep over this.
robsc501
Last edited by robsc501; 10-09-2008 at 08:47 AM.
10-09-2008, 08:54 AM
#6
Pro
My 00 is very bad when cold and goes away in 1-2 minutes. My wife keeps saying, "what is that noise"? I tell her to keep talking and I won't hear it! Just drive it easy until it goes away. There are reports of 250,000 miles on engines with this problem.
10-09-2008, 11:11 AM
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Burning Brakes
10-09-2008, 11:14 AM
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St. Jude Donor '08-'09
Hi There:
The piston slap you hear is the carbon build up on the ring lands causing the pistons to rock. This sounds like valve tappet noise.Starting in the 2002 model year the pistons were teflon coated to eliminate this problem at start-up or cold temperature operation.I would run a few cans of this fuel injection cleaner.Its called BG 44K made by Bg Products Inc. since 1971.After a few cans of this most of the carbon will be reduced. The noise will go away. However it will return, one of the down sides of using high octane fuel. My 01 stock coupe with 15k does the same thing until warm up is completed. Another good fuel injection cleaner is Techron Plus. Bg 44K is only obtainable from dealers, formerly called mechanics injection cleaner. About $20. for 11 oz. can. I would not lose any sleep over this.
robsc501
The piston slap you hear is the carbon build up on the ring lands causing the pistons to rock. This sounds like valve tappet noise.Starting in the 2002 model year the pistons were teflon coated to eliminate this problem at start-up or cold temperature operation.I would run a few cans of this fuel injection cleaner.Its called BG 44K made by Bg Products Inc. since 1971.After a few cans of this most of the carbon will be reduced. The noise will go away. However it will return, one of the down sides of using high octane fuel. My 01 stock coupe with 15k does the same thing until warm up is completed. Another good fuel injection cleaner is Techron Plus. Bg 44K is only obtainable from dealers, formerly called mechanics injection cleaner. About $20. for 11 oz. can. I would not lose any sleep over this.
robsc501
10-09-2008, 01:18 PM
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Thanks very much, I'll try the BG 44K and I'm sure it's just the carbon buildup. It not a tap and it's not a rod knock, it's just a light knock until I hit 180 degrees, then it's gone for the rest of the day. I'm just glad I have friends with the same situation. Thanks again !
