piston slap or not????
broughy84
12-09-2004, 06:28 PM
I got a new work truck today it's a 1996 Chevy C1500, 4.3L V6 4L60E. Anyway when you start it it make a knocking sound, not real loud, it you have the radio on you cant hear it, and you need the door open to hear it. Now it goes away as soon as the oil circulates good. Could this be the "piston slap" everyone talks so much about or do I have a spun bearing?
frankendart
12-09-2004, 08:38 PM
From your description of the noise, it sounds as though you do have piston slap. Sorry.
GM still has not gotten a handle on that problem.
GM still has not gotten a handle on that problem.
broughy84
12-09-2004, 09:44 PM
should I be worried
frankendart
12-09-2004, 10:01 PM
That's a good question. I've seen trucks with 200,000 miles, most of which were clocked with the pistons slaping the cylinder walls. On the other hand, someone very close to me had to replace the engine in their new truck with less than 40K miles on it.
I would definately use a good grade oil, and keep up with the changes. If there is a garage around your area that does oil analysis, you might consider doing one every 6 months or so to learn what's going on inside your engine. It could save you a ton of money in the long run.
I would definately use a good grade oil, and keep up with the changes. If there is a garage around your area that does oil analysis, you might consider doing one every 6 months or so to learn what's going on inside your engine. It could save you a ton of money in the long run.
Seabornman
12-10-2004, 07:52 AM
You don't have piston slap. You have the 4.3 V6 which is basically a cut back V8, the same short block Chevy made millions of, which had no problems with piston slap. Most likely, you have lifter noise when you start up. My 91 V6 had 150,000 miles when I sold it and had a little lifter noise when started, and a puff of blue smoke from oil getting past worn valve guide seals, but otherwise was strong. You might try one of the miracle top end cleaners you can buy at auto parts stores. I believe GM sells a top end oil.
If you had a spun bearing, you would know it. Noise won't go away.
If you had a spun bearing, you would know it. Noise won't go away.
frankendart
12-11-2004, 07:17 AM
http://piston%20slap.com/
They list all the engines that have developed piston slap, and the 4.3 is one of them. They also have an audio of an engine with piston slap. The audio is pretty close to what a friends engine sounded like before it was replaced.
If your engine sounds like the audio, there are a few things you can try to correct it. Piston slap is also refered to as "CSK" which stands for Cold Start Knock. I heard and read of dealers telling owners that it's a "normal" or "harmless" noise. I'm not sure how anyone could design an engine that capable of developing a noise like Piston slap, and still call it "NORMAL" .
I hope, for your sake, that it is a lifter noise as Seabornman says. But don't take our diagnosis as gospel, were are both just guessing. Get it checked out for real.
Good Luck.
If you have a problem getting this page to load, here is a copy of the sites home page:
"The very evidence provided by the manufacturer
(GM) to indicate this condition is not a problem ultimately demonstrates that it is a problem."
California BBB Arbitrator 12/03
"...a knocking engine could lower the value
of a vehicle by $4,000 to $6,000 at trade-in"
Charlie Vogelheim, executive editor for Kelley Blue Book
Detroit Free Press 02/21/04
"My 2004 8.1L is knocking with less then 2K miles"
post on pistonslap.com forum (click here)
Lawyers, GM spar over data on engine problems
Detroit News Auto Insider 9/04 (full article here)
GM Consumers, do you have a 1999-2003 (2004?) 3.1, 3.4, 4.3, 4.6 (Northstar), 4.8, 5.3, 5.7(LS1), 6.0 or 8.1 liter engine that displays any of the following problems?
A loud embarrassing and annoying internal engine knock. Many are defective due to design and manufacturing quality consistency problems. Listen to piston slap here.
Higher than normal levels of wear related materials in oil analysis samples performed by independent laboratories.
Vertical piston and cylinder wall scuffing/scratching or scoring on the hammering (noisy) cylinders upon visual inspection. See photos here.
Reduced combustion chamber compression on the hammering (noisy) cylinders.
Increased oil consumption.
Increased exhaust emissions.
Did GM or there agents tell you they would fix your defective vehicle in writing/and/or verbally when the phantom "New Piston" fix WAS TO arrive in the spring or summer of 2002? GM did in fact admit it had a problem and that its engineering department was working on the fix. The fix was promised to be made to consumer’s engines in the spring or summer of 2002. As the number of slapping engines grew and the cost to repair them grew as well, GM changed its policy.
We are receiving complaints from fellow slappers who are taking their vehicle's into dealerships for piston slap. Apparently some dealerships are saying it is 'normal' and not giving the consumer a work order, even when asked to do so. If this happens to you be sure to keep the following information for your records:
1. Date of repair attempt
2. Time of repair attempt
3. Service writer/managers name**
4. Name of person refusing work order**
5. Service tech's name refusing to do work**
6. Any other items/notes/observations to show proof you were there
** - Write down names in front of the person.
They list all the engines that have developed piston slap, and the 4.3 is one of them. They also have an audio of an engine with piston slap. The audio is pretty close to what a friends engine sounded like before it was replaced.
If your engine sounds like the audio, there are a few things you can try to correct it. Piston slap is also refered to as "CSK" which stands for Cold Start Knock. I heard and read of dealers telling owners that it's a "normal" or "harmless" noise. I'm not sure how anyone could design an engine that capable of developing a noise like Piston slap, and still call it "NORMAL" .
I hope, for your sake, that it is a lifter noise as Seabornman says. But don't take our diagnosis as gospel, were are both just guessing. Get it checked out for real.
Good Luck.
If you have a problem getting this page to load, here is a copy of the sites home page:
"The very evidence provided by the manufacturer
(GM) to indicate this condition is not a problem ultimately demonstrates that it is a problem."
California BBB Arbitrator 12/03
"...a knocking engine could lower the value
of a vehicle by $4,000 to $6,000 at trade-in"
Charlie Vogelheim, executive editor for Kelley Blue Book
Detroit Free Press 02/21/04
"My 2004 8.1L is knocking with less then 2K miles"
post on pistonslap.com forum (click here)
Lawyers, GM spar over data on engine problems
Detroit News Auto Insider 9/04 (full article here)
GM Consumers, do you have a 1999-2003 (2004?) 3.1, 3.4, 4.3, 4.6 (Northstar), 4.8, 5.3, 5.7(LS1), 6.0 or 8.1 liter engine that displays any of the following problems?
A loud embarrassing and annoying internal engine knock. Many are defective due to design and manufacturing quality consistency problems. Listen to piston slap here.
Higher than normal levels of wear related materials in oil analysis samples performed by independent laboratories.
Vertical piston and cylinder wall scuffing/scratching or scoring on the hammering (noisy) cylinders upon visual inspection. See photos here.
Reduced combustion chamber compression on the hammering (noisy) cylinders.
Increased oil consumption.
Increased exhaust emissions.
Did GM or there agents tell you they would fix your defective vehicle in writing/and/or verbally when the phantom "New Piston" fix WAS TO arrive in the spring or summer of 2002? GM did in fact admit it had a problem and that its engineering department was working on the fix. The fix was promised to be made to consumer’s engines in the spring or summer of 2002. As the number of slapping engines grew and the cost to repair them grew as well, GM changed its policy.
We are receiving complaints from fellow slappers who are taking their vehicle's into dealerships for piston slap. Apparently some dealerships are saying it is 'normal' and not giving the consumer a work order, even when asked to do so. If this happens to you be sure to keep the following information for your records:
1. Date of repair attempt
2. Time of repair attempt
3. Service writer/managers name**
4. Name of person refusing work order**
5. Service tech's name refusing to do work**
6. Any other items/notes/observations to show proof you were there
** - Write down names in front of the person.
frankendart
12-11-2004, 07:39 AM
Here's one of the media stories...
Lawyers, GM spar over data on engine problems
Group runs ads seeking more information for suit
By Ed Garsten / The Detroit News
DETROIT — Lawyers battling General Motors Corp. over allegedly defective engines turned up the heat this week by accusing the automaker of withholding documents and running newspaper ads soliciting new information.
The ads, which began running Tuesday in The Detroit News and Detroit Free Press, ask GM employees or others for information or documents that would help the lawsuit against the automaker. They were paid for by Charfoos & Christensen, a law firm in Detroit representing more than 300 plaintiffs in the suit against GM.
The law firm filed suit last October in U.S. District Court in Detroit claiming that GM produced defective engines used in about 800,000 1999-2002 pickup trucks and sport utility vehicles.
“We need GM to produce documents,” said J.D. Peters, an attorney at Charfoos & Christensen. “We don’t trust GM to produce the documents.”
GM denounced Peters’ accusations that the automaker would destroy or withhold evidence.
“It’s reprehensible for him to even suggest that,” said GM spokeswoman Brenda Rios. “The ad speaks volumes about their case in that they have to advertise in the newspaper for evidence to support their claims.”
The plantiffs claim the engines are plagued by loud knocking noise known as “piston slap.” The noise is caused when the pistons knock against the side of the cylinder because the clearance between the piston and cylinder is too wide, according to the complaint.
Peters said the law firm’s telephones were “ringing all day” as a result of the ads, which will run “as long as we keep getting results.”
In a statement, GM calls the problem a “tick” and said it “disappears after about 5 to 30 seconds as the engine warms up.” The problem has been reported by a small percentage of owners with 4.8 liter, 5.3 liter and 6.0 liter displacement engines, according to the statement.
The Detroit lawsuit has been combined with similar suits filed in Oklahoma, Florida and Massachusetts. The lawsuits are seeking class action status.
Dan Powell, 46, of Casselberry, Fla., one of the lead plaintiffs in the case, says the knocking sound started a few thousand miles after he bought a 2001 GMC Yukon XL sport utility vehicle. The sound subsides after the truck warms up but “doesn't go away,” he said. His dealer told him the sound was normal, Powell said.
After five unsuccessful attempts to have the problem fixed, Powell and his wife decided to take legal action.
“As a consumer, our obligation is to take it back to the manufacturer,” said Powell, the owner of an Internet design company. “They tell me they're not going to fix it.”
He hasn't tried to sell the SUV, pointing out the executive editor of Kelly Blue Book has said a knocking engine could lower the value by $4,000-$6,000 at trade-in.
Other owners claim their vehicles, equipped with V-8 engines ranging in size from 3.1 liters to 8.1 liters, have lost resale value because of the problem. They also allege GM knew about the defect when the vehicles were sold.
“We're prepared to defend the allegations vigorously,” said GM's Rios. “We don't believe this condition affects the durability, reliability or performance of the engine.”
A spokesman for the National Highway Traffic Safety Administration said the agency does not track consumer complaints for piston slap since it is not a safety issue.
The plaintiffs are asking for damages and for GM to replace the engines or buy back the vehicles.
You can reach Ed Garsten at (313) 223-3217 or [email protected].
Lawyers, GM spar over data on engine problems
Group runs ads seeking more information for suit
By Ed Garsten / The Detroit News
DETROIT — Lawyers battling General Motors Corp. over allegedly defective engines turned up the heat this week by accusing the automaker of withholding documents and running newspaper ads soliciting new information.
The ads, which began running Tuesday in The Detroit News and Detroit Free Press, ask GM employees or others for information or documents that would help the lawsuit against the automaker. They were paid for by Charfoos & Christensen, a law firm in Detroit representing more than 300 plaintiffs in the suit against GM.
The law firm filed suit last October in U.S. District Court in Detroit claiming that GM produced defective engines used in about 800,000 1999-2002 pickup trucks and sport utility vehicles.
“We need GM to produce documents,” said J.D. Peters, an attorney at Charfoos & Christensen. “We don’t trust GM to produce the documents.”
GM denounced Peters’ accusations that the automaker would destroy or withhold evidence.
“It’s reprehensible for him to even suggest that,” said GM spokeswoman Brenda Rios. “The ad speaks volumes about their case in that they have to advertise in the newspaper for evidence to support their claims.”
The plantiffs claim the engines are plagued by loud knocking noise known as “piston slap.” The noise is caused when the pistons knock against the side of the cylinder because the clearance between the piston and cylinder is too wide, according to the complaint.
Peters said the law firm’s telephones were “ringing all day” as a result of the ads, which will run “as long as we keep getting results.”
In a statement, GM calls the problem a “tick” and said it “disappears after about 5 to 30 seconds as the engine warms up.” The problem has been reported by a small percentage of owners with 4.8 liter, 5.3 liter and 6.0 liter displacement engines, according to the statement.
The Detroit lawsuit has been combined with similar suits filed in Oklahoma, Florida and Massachusetts. The lawsuits are seeking class action status.
Dan Powell, 46, of Casselberry, Fla., one of the lead plaintiffs in the case, says the knocking sound started a few thousand miles after he bought a 2001 GMC Yukon XL sport utility vehicle. The sound subsides after the truck warms up but “doesn't go away,” he said. His dealer told him the sound was normal, Powell said.
After five unsuccessful attempts to have the problem fixed, Powell and his wife decided to take legal action.
“As a consumer, our obligation is to take it back to the manufacturer,” said Powell, the owner of an Internet design company. “They tell me they're not going to fix it.”
He hasn't tried to sell the SUV, pointing out the executive editor of Kelly Blue Book has said a knocking engine could lower the value by $4,000-$6,000 at trade-in.
Other owners claim their vehicles, equipped with V-8 engines ranging in size from 3.1 liters to 8.1 liters, have lost resale value because of the problem. They also allege GM knew about the defect when the vehicles were sold.
“We're prepared to defend the allegations vigorously,” said GM's Rios. “We don't believe this condition affects the durability, reliability or performance of the engine.”
A spokesman for the National Highway Traffic Safety Administration said the agency does not track consumer complaints for piston slap since it is not a safety issue.
The plaintiffs are asking for damages and for GM to replace the engines or buy back the vehicles.
You can reach Ed Garsten at (313) 223-3217 or [email protected].
frankendart
12-11-2004, 07:48 AM
...and another story...
Call 4 Action: GM Truck Knock
POSTED: 5:09 pm EST February 4, 2004
Thousands of truck owners are complaining to General Motors about an irritating noise in their engines, Call 4 Action reporter Susan Koeppen says.
A "knock" is being reported in models like the GMC Yukon and the Chevrolet Silverado, mostly between 1999 and 2002. Owners say the problem is a loud sound of pistons hitting the cylinders.
One owner, Aaron Trapuzzano, was given a 100,000-mile warranty when he voiced his complaint to GM. Now, he's taking action under Pennsylvania's Lemon Law.
GM officials say carbon and the amount of clearance between the piston and the cylinder wall are the primary causes of the knocking. Owners who hear loud and continuing engine knocking should take the vehicle to an authorized GM dealer for inspection and repairs.
Click here to learn more about this problem at pistonslap.com.
Copyright 2004 by ThePittsburghChannel
Call 4 Action: GM Truck Knock
POSTED: 5:09 pm EST February 4, 2004
Thousands of truck owners are complaining to General Motors about an irritating noise in their engines, Call 4 Action reporter Susan Koeppen says.
A "knock" is being reported in models like the GMC Yukon and the Chevrolet Silverado, mostly between 1999 and 2002. Owners say the problem is a loud sound of pistons hitting the cylinders.
One owner, Aaron Trapuzzano, was given a 100,000-mile warranty when he voiced his complaint to GM. Now, he's taking action under Pennsylvania's Lemon Law.
GM officials say carbon and the amount of clearance between the piston and the cylinder wall are the primary causes of the knocking. Owners who hear loud and continuing engine knocking should take the vehicle to an authorized GM dealer for inspection and repairs.
Click here to learn more about this problem at pistonslap.com.
Copyright 2004 by ThePittsburghChannel
frankendart
12-11-2004, 07:52 AM
....and yet another report...
Customer Test Drive
2001 Chevrolet Silverado 2500HD LS Back to Chevrolet Silverado Reviews
Ratings ( Maximum score is 100 )
Overall: ( 40 )
Comfort: ( 60 )
Performance: ( 60 )
Quality: ( 20 )
Appearance: ( 60 )
Comments
Favorite feature:
6.0L had power before the piston slap rendered it ineffective
Least favorite feature:
Numerous problems and lack of customer support - especially piston slap!
Advice to buyer:
Read reviews, forums, etc. Many websites censored, esp. regarding piston slap issue.
Detailed review:
My 2001 Silverado 6L gas suffers from a variety of poor quality and engineering issues. The dreaded but 'normal' (according to GM) GM piston slap turns heads as I rattle by. Steering column 'clunk', misaligned box; all problems reported by most owners. Check before you buy!
About This Reviewer...
Name:
Lowell Hassler
Email address:
[email protected]
Location:
Lewistown, Montana
Review submitted:
December 02, 2002
--------------------------------------------------------------------------------
Note: Autoweb.com provides Customer Test Drives as an open forum for individuals to share their views during the test drive experience. The opinions, comments and views expressed in this section are solely those of such individuals. Neither Autoweb.com, its subsidiaries and affiliates, nor any Autoweb.com subscribing dealer or vehicle manufacturer endorse any view or opinion expressed in this section unless specifically noted.
Customer Test Drive
2001 Chevrolet Silverado 2500HD LS Back to Chevrolet Silverado Reviews
Ratings ( Maximum score is 100 )
Overall: ( 40 )
Comfort: ( 60 )
Performance: ( 60 )
Quality: ( 20 )
Appearance: ( 60 )
Comments
Favorite feature:
6.0L had power before the piston slap rendered it ineffective
Least favorite feature:
Numerous problems and lack of customer support - especially piston slap!
Advice to buyer:
Read reviews, forums, etc. Many websites censored, esp. regarding piston slap issue.
Detailed review:
My 2001 Silverado 6L gas suffers from a variety of poor quality and engineering issues. The dreaded but 'normal' (according to GM) GM piston slap turns heads as I rattle by. Steering column 'clunk', misaligned box; all problems reported by most owners. Check before you buy!
About This Reviewer...
Name:
Lowell Hassler
Email address:
[email protected]
Location:
Lewistown, Montana
Review submitted:
December 02, 2002
--------------------------------------------------------------------------------
Note: Autoweb.com provides Customer Test Drives as an open forum for individuals to share their views during the test drive experience. The opinions, comments and views expressed in this section are solely those of such individuals. Neither Autoweb.com, its subsidiaries and affiliates, nor any Autoweb.com subscribing dealer or vehicle manufacturer endorse any view or opinion expressed in this section unless specifically noted.
buttnekked
12-11-2004, 11:16 AM
presumably no one has changed the engine and it is a 96 as well the most likely cause is valve train noise. It goes away once oil reaches the top of the engine. It could be as simple as the heads are crapped up from lack of oil changes or it make be mechanical. Weak lifters or valves out of adjustment could cause this easily. I can't rule out piston slap or a bearing starting to spread without actually checking the engine myself but you can pickup a cheap mechanics stethoscope and isolate the noise to get a better idea.
rrousou
12-30-2004, 11:46 PM
A friend of mine's 5.7L had a bad case of piston slap. After getting the run around from GM he had a Performance Machine Shop bore out the cylinders and had aftermarket high performance pistons and rods installed. They also re-cammed the engine , recalibrated the ECM, upgraded the exhaust system and dyno'd the truck. Problem solved along with a whole lot more performance.
gschretter
12-31-2004, 10:32 AM
I got a new work truck today it's a 1996 Chevy C1500, 4.3L V6 4L60E. Anyway when you start it it make a knocking sound, not real loud, it you have the radio on you cant hear it, and you need the door open to hear it. Now it goes away as soon as the oil circulates good. Could this be the "piston slap" everyone talks so much about or do I have a spun bearing?
I have heard about all this piston slap stuff. This is what it really is.
DRY START. The bearings are rubbing metal to metal. GM does not want people to know that DRY start is killing their motors.
PERIOD.
This piston slap crap is so BS. Something the dealership made up.
I have a 79 350 that does the same thing because the bearning are wearing out.
Piston Slap Defined:
The knocking of the piston on the head due to carbon build up.
Well if that is true then you would hear it all the time especially at high RPMS where the metal of the robs are stretched due to force.
It is not a bad sign just the design of the motor is really tight.
It is just basic wear on the motor. Drive it until the pistons shoot out of the block.
Here do a test.
In the morning.
1. Unplug coil wire
2. Crank motor on for 10 seconds
3. Turn key off
4. Repeat step 2 and 3 about 4 times.
5. Plug in coil wire
6. Start vehcile
7. Listen - no (PISTON SLAP)
On my jeep 350, I use a pre-oil system so that I do not have DRY START. One time I forgot to turn it one and started the motor and thought the crankshaft fell out.
You can find out about pre-oiling system at: www.summitracing.com
I have heard about all this piston slap stuff. This is what it really is.
DRY START. The bearings are rubbing metal to metal. GM does not want people to know that DRY start is killing their motors.
PERIOD.
This piston slap crap is so BS. Something the dealership made up.
I have a 79 350 that does the same thing because the bearning are wearing out.
Piston Slap Defined:
The knocking of the piston on the head due to carbon build up.
Well if that is true then you would hear it all the time especially at high RPMS where the metal of the robs are stretched due to force.
It is not a bad sign just the design of the motor is really tight.
It is just basic wear on the motor. Drive it until the pistons shoot out of the block.
Here do a test.
In the morning.
1. Unplug coil wire
2. Crank motor on for 10 seconds
3. Turn key off
4. Repeat step 2 and 3 about 4 times.
5. Plug in coil wire
6. Start vehcile
7. Listen - no (PISTON SLAP)
On my jeep 350, I use a pre-oil system so that I do not have DRY START. One time I forgot to turn it one and started the motor and thought the crankshaft fell out.
You can find out about pre-oiling system at: www.summitracing.com
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