Piston slap help
Thread Starter
Melting Slicks
Joined: Sep 2003
Posts: 2,669
Likes: 5
From: Florida Gulf Coast
St. Jude Donor '05-'06-'10-'11
Piston slap help
Anyone have a piston slap problem while in warranty and wondering what the outcome was? I sure would appreciate any input before I take on the dealer. Mine is a 2002 coupe with 4,400 miles.
[Modified by WolfeBros, 11:42 PM 10/3/2003]
[Modified by WolfeBros, 11:42 PM 10/3/2003]
Intermediate
Joined: Oct 2002
Posts: 44
Likes: 0
From: lakewood nj
Re: Piston slap help (VetteDrmr)
I believe you are right about the pinging rather than piston slap. After finding carbon in the cylinder it makes more sense. Carbon deposits get hot and tend to glow in the chamber, causing pre-ignition(pinging). Cleaning with the GM solvent removes the carbon and --------------no more pinging, for a while. Take it up to 6000 rpm once in a while(3-5) days a week!!!!!!!
:steering:
:steering:
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Re: Piston slap help (98CFive)
98
QUOTE" believe you are right about the pinging rather than piston slap. After finding carbon in the cylinder it makes more sense. Carbon deposits get hot and tend to glow in the chamber, causing pre-ignition(pinging). Cleaning with the GM solvent removes the carbon and --------------no more pinging, for a while. Take it up to 6000 rpm once in a while(3-5) days a week!!!!!!!
Whoooooooooo,,,,,,60000 rpm once in a while(3-5) days a week!!!!!!! Man, mine must be like BRAND NEW inside!! :D :D :thumbs: I do that 3-5 times a day all week! :lol:
Bill C
QUOTE" believe you are right about the pinging rather than piston slap. After finding carbon in the cylinder it makes more sense. Carbon deposits get hot and tend to glow in the chamber, causing pre-ignition(pinging). Cleaning with the GM solvent removes the carbon and --------------no more pinging, for a while. Take it up to 6000 rpm once in a while(3-5) days a week!!!!!!!
Whoooooooooo,,,,,,60000 rpm once in a while(3-5) days a week!!!!!!! Man, mine must be like BRAND NEW inside!! :D :D :thumbs: I do that 3-5 times a day all week! :lol:
Bill C
Le Mans Master
Joined: Feb 1999
Posts: 6,269
Likes: 1
From: Richmond Ca
Re: Piston slap help (Bill Curlee)
98
QUOTE" believe you are right about the pinging rather than piston slap. After finding carbon in the cylinder it makes more sense. Carbon deposits get hot and tend to glow in the chamber, causing pre-ignition(pinging). Cleaning with the GM solvent removes the carbon and --------------no more pinging, for a while. Take it up to 6000 rpm once in a while(3-5) days a week!!!!!!!
Whoooooooooo,,,,,,60000 rpm once in a while(3-5) days a week!!!!!!! Man, mine must be like BRAND NEW inside!! :D :D :thumbs: I do that 3-5 times a day all week! :lol:
Bill C
QUOTE" believe you are right about the pinging rather than piston slap. After finding carbon in the cylinder it makes more sense. Carbon deposits get hot and tend to glow in the chamber, causing pre-ignition(pinging). Cleaning with the GM solvent removes the carbon and --------------no more pinging, for a while. Take it up to 6000 rpm once in a while(3-5) days a week!!!!!!!
Whoooooooooo,,,,,,60000 rpm once in a while(3-5) days a week!!!!!!! Man, mine must be like BRAND NEW inside!! :D :D :thumbs: I do that 3-5 times a day all week! :lol:
Bill C
The piston slap is a knocking sound, like someone is inside pounding the cylinder walls with a hammer.
Pre-ignition is a lighter, rattling sound; Like pebbles rattling around in a pipe or in a tin can. :cheers:
Thread Starter
Melting Slicks
Joined: Sep 2003
Posts: 2,669
Likes: 5
From: Florida Gulf Coast
St. Jude Donor '05-'06-'10-'11
Re: Piston slap help (wwashing)
:iagree: Two different problems with two different sounds. What is ironic is that the piston slap sounds worse but actually causes no real damage while a pinging, or predetonation can cause serious damage if it goes on without check.
Drifting
Joined: May 2003
Posts: 1,755
Likes: 97
From: Sandy Utah
Re: Piston slap help (WolfeBros)
My Vette has a tic, tic. tic sound only when it is first started and is warm. A few blips of the throttle and it goes away. I have talked to a couple of service writers and they say it is injector noise!!! It does not make any noise when it is started cold. Who knows what the Shadow knows. :D :D
Advanced
Joined: Sep 2003
Posts: 54
Likes: 0
Re: Piston slap help (WolfeBros)
I have 21,000 on my 2002. I ran two bottles of the GM top end cleaner and the slap noise disappeared. 2,000 miles later, its baaack. Guess the gent who recommended buying a case of the GM cleaner was right. However, instead of paying $13 a bottle, you can buy an alternative brand (i.e. Chevron, Slick 50, etc.) that does the same thing at Walmart for $5. I understand the dealer won't tear down an engine to fix this problem because "its normal." I heard that GM engineers have since begun "coating" pistons to take care of the noise on 2003's. Guess I'm stuck with a $40K tractor.....well, at least its fast. :mad
Pro
Joined: Jun 2003
Posts: 702
Likes: 0
From: Castle Rock Co
Re: Piston slap help (angstr1)
The evap purge soleniod on my 98 LS1 Camaro would tick just like a lifter when the engine was cold.
Try unplugging the EVAP soleniod when the engine is ticking and see if it goes away.
Try unplugging the EVAP soleniod when the engine is ticking and see if it goes away.
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Burning Brakes
Joined: Jan 2000
Posts: 1,226
Likes: 80
From: Ohio
Re: Piston slap help (Heretic)
I was wondering if anyone has tried to correct the piston slap problem with a thicker film synthetic such as amsoil, or royal purple ? From what I understand about the problem this may help. As far as carbon build up goes would a hotter spark plug help in burning the fuel more completely ? And thus reduce carbon ? Just my .02 Nick :seeya
Former Vendor
Joined: Apr 2001
Posts: 10,976
Likes: 21
From: FL
St. Jude Donor '13
Re: Piston slap help (VetteDrmr)
... Someone advised me that the slap I was hearing with the 02 was the result of carbon build-up and recommended running a couple of tanks of gas through with GM part #12345515 in each tank
Isn't that detonation (a.k.a. pinging)? I thought piston slap was actually the skirts of the piston contacting the cylinder walls when the engine was cold and the tolerances were larger. Then, as the pistons & cylinder walls warm up, the tolerances go down and the slap goes away. Don't see how carboning up a cylinder can cause piston slap.
Or, am I wrong?
Have a good one,
Mike
Isn't that detonation (a.k.a. pinging)? I thought piston slap was actually the skirts of the piston contacting the cylinder walls when the engine was cold and the tolerances were larger. Then, as the pistons & cylinder walls warm up, the tolerances go down and the slap goes away. Don't see how carboning up a cylinder can cause piston slap.
Or, am I wrong?
Have a good one,
Mike
Carbon knock is caused by carbon deposits being compressed between the piston and cylinder head,or between the back of a valve and the cylinder head.Carbon deposits are hard as a rock,and as the engine warms the carbon becomes softer resulting in the noise going away.Both noises are similar and often misdiagnosed.Carbon knock will generally be louder.
Short of major surgery,nothing in a bottle will eliminate piston slap.Carbon knock can be eliminated with the decarbon procedure,or prevented with Techron in the tank as preventitive maintanance :thumbs:
Advanced
Joined: Sep 2003
Posts: 54
Likes: 0
Re: Piston slap help (C-5 TECH)
... There is alot of confusion here...The two most common cold start noises are caused by "piston slap" or "carbon knock".Piston slap is simply caused by the piston rocking in the bore caused by the "short skirt" design of the piston.As the piston expands with temperature,the noise goes away.
Former Vendor
Joined: Apr 2001
Posts: 10,976
Likes: 21
From: FL
St. Jude Donor '13
Re: Piston slap help (angstr1)
When I stated carbon knock,I was not refering to pinging.Carbon knock is a noise simular to piston slap,caused by the piston or valve trying to compress the carbon deposits.
The C5 uses a piston design that is also used in many high performance engines and race engines.Though the piston noise is annoying and I agree,it is the nature of the beast.
GM has determined the the piston slap is not a durability issue,but they coated the pistons in 2002 to allow for a tighter fitting piston to address this issue.
The C5 uses a piston design that is also used in many high performance engines and race engines.Though the piston noise is annoying and I agree,it is the nature of the beast.
GM has determined the the piston slap is not a durability issue,but they coated the pistons in 2002 to allow for a tighter fitting piston to address this issue.
