Piston Slap
Thread Starter
Burning Brakes
Joined: Jul 2007
Posts: 1,165
Likes: 57
From: Halcottsville NY
Piston Slap
I'm sure this has been mentioned before, but, does piston slap damage the engine over time ? I've developed this occurance, repeatedly, until the engine warms up. Once it's up to temperature, there's no noise. I find it really annoying and I'm not sure of any future damage it might do.
BTW- 20,400 miles on an 07' coupe.
BTW- 20,400 miles on an 07' coupe.
Race Director
Joined: Nov 2005
Posts: 14,548
Likes: 1,536
From: Supporting the Corvette Community at Abel Chevrolet in Rio Vista, CA 707-374-6317 Ext.123
St. Jude Donor '08
Piston slap is a made up term that is 
The dumba$$es that made the piston slap dot com website should be "piston slapped" in their damn faces. These motors are noticably noisier then many others. The reasons have been discussed at lengths on here. I have been working around these motors since their inception and have yet to see one fail due to any reason even remotely related to the BS piston slap noise.
Your car is fine and will continue to be fine for a long time so enjoy it.
RICH
The dumba$$es that made the piston slap dot com website should be "piston slapped" in their damn faces. These motors are noticably noisier then many others. The reasons have been discussed at lengths on here. I have been working around these motors since their inception and have yet to see one fail due to any reason even remotely related to the BS piston slap noise.
Your car is fine and will continue to be fine for a long time so enjoy it.
RICH
Moderator
Joined: Feb 2006
Posts: 38,882
Likes: 17,781
From: DFW Area TX
If the piston slap is excessive, it could damage the engine over time.
Piston slap is nothing new to piston driven internal combustion engines and compressors. It is the secondary (sideways or perpendicular) movement of a piston against the side of a cylinder bore where the primary movement of a piston is intended to be parallel (up and down) to the cylinder bore. All piston driven internal combustion engines and compressors have a certain amount of piston slap.
Excessive piston slap occurs when the clearance between the piston and the cylinder bore is too great. The piston to cylinder bore clearance becomes too great either through wear, mismatched pistons and cylinder bores at manufacturing or, a combination of both. The audible noise associated with excessive piston slap is due to the perpendicular impact of the piston against the wall of the cylinder bore. Audible piston slap is typically loudest when the engine is first started up. The pistons then expand with heat reducing the piston to cylinder bore clearance thus, reducing the perpendicular impact of the piston against the cylinder wall and its resulting noise.
Excessive piston slap occurs when the clearance between the piston and the cylinder bore is too great. The piston to cylinder bore clearance becomes too great either through wear, mismatched pistons and cylinder bores at manufacturing or, a combination of both. The audible noise associated with excessive piston slap is due to the perpendicular impact of the piston against the wall of the cylinder bore. Audible piston slap is typically loudest when the engine is first started up. The pistons then expand with heat reducing the piston to cylinder bore clearance thus, reducing the perpendicular impact of the piston against the cylinder wall and its resulting noise.
Instructor
Joined: Sep 2008
Posts: 207
Likes: 0
From: BEAUFORT SC
I'm sure this has been mentioned before, but, does piston slap damage the engine over time ? I've developed this occurance, repeatedly, until the engine warms up. Once it's up to temperature, there's no noise. I find it really annoying and I'm not sure of any future damage it might do.
BTW- 20,400 miles on an 07' coupe.
BTW- 20,400 miles on an 07' coupe.
Thread Starter
Burning Brakes
Joined: Jul 2007
Posts: 1,165
Likes: 57
From: Halcottsville NY
I have a 2009 model with over 21,000 miles on it now and I started noticing the same sort of noise each morning upon first start until the engine warmed up. Generally it goes away after 15 seconds to one minute and it can occur at any time during the day, but mostly after the car has sat around for at least a few hours. I have had the dealership, mechanics, and other owners of Corvettes tell me this noise is normal and causes no damage. I have four friends with late model Vettes and they all experience the same thing. Whether it’s valve tapping or piston slap or whatever the heck it is, many owners seem to have it. I try not to think about it too much. The problem is explaining it to a person who might be in the car at the time when the noise occurs ---- it’s not a quality sound that one can be proud of nor does it impress. Hope that helps.
Instructor
Joined: Apr 2009
Posts: 243
Likes: 0
From: Katy TX
I wouldn't worry about it too much. My 2000 Z28 (LS1) had about 106,000 miles on it when I sold it, and had the cold start slap for several years. Engine internals were stock, aside from an oil pump, and the only real performance mods were a tune and exhaust (long tube headers, catted Y-pipe and catback). A couple weeks before I sold it, it made 334rwhp, so I can't say it was down on power after all those miles and all that slapping.
-Mike
-Mike
Melting Slicks
Joined: Oct 2008
Posts: 3,355
Likes: 11
From: Beverly Hills, MI
It is probably dry lifter noise? This would be my first guess.
If you have true piston slap, be prepared for an early-life failure of a piston, and then guess what...
Piston slap is VERY rare at 20,000 miles. More like an engine with 100,000 miles with poor engine maintenance and using crap oil for a majority of it's lifetime resulting in poor oiling in the engine due to plugged passages (assuming that there isn't a defective piston or poor metalergy in the bore).
If you have true piston slap, be prepared for an early-life failure of a piston, and then guess what...
Piston slap is VERY rare at 20,000 miles. More like an engine with 100,000 miles with poor engine maintenance and using crap oil for a majority of it's lifetime resulting in poor oiling in the engine due to plugged passages (assuming that there isn't a defective piston or poor metalergy in the bore).
Team Owner
Joined: Sep 2000
Posts: 24,964
Likes: 2,679
From: Far NW 'burbs of Chicago
St. Jude Donor '13
The LS1 engines in the C5 were well known for piston slap, which GM said was harmless. Beginning around 2002, they started using a Teflon coating on the pistons (skirts?), GM said it reduced the noise but made no difference in engine longevity because the typical slap on the earlier engines was not a problem.
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Melting Slicks
Joined: Feb 2004
Posts: 3,307
Likes: 110
From: Tucson AZ
The first question is, "Are you actually hearing piston slap, or is it hydraulic roller lifter tapping, possibly injector noise, or maybe a rod bearing".
Then the discussion can proceed to "Is it damaging your engine".
The best example of piston slap noise is a 2-stroke dirt bike at cold start up.
Maybe consider an extended warranty and then just enjoy your car and not worry about the noise?
Then the discussion can proceed to "Is it damaging your engine".
The best example of piston slap noise is a 2-stroke dirt bike at cold start up.
Maybe consider an extended warranty and then just enjoy your car and not worry about the noise?
Last edited by Vito.A; Aug 25, 2009 at 07:04 PM.
GM Cert Corvette Tech
Joined: Apr 2008
Posts: 2,559
Likes: 585
From: Anaheim Hills California
Piston slap is a made up term that is
The dumba$$es that made the piston slap dot com website should be "piston slapped" in their damn faces. These motors are noticably noisier then many others. The reasons have been discussed at lengths on here. I have been working around these motors since their inception and have yet to see one fail due to any reason even remotely related to the BS piston slap noise.
Your car is fine and will continue to be fine for a long time so enjoy it.
RICH
The dumba$$es that made the piston slap dot com website should be "piston slapped" in their damn faces. These motors are noticably noisier then many others. The reasons have been discussed at lengths on here. I have been working around these motors since their inception and have yet to see one fail due to any reason even remotely related to the BS piston slap noise.
Your car is fine and will continue to be fine for a long time so enjoy it.
RICH
