Question about piston slap...Does it hurt the engine ?

Soo every morning I wake up and start the 02'silverado i hear it slapping,it only slaps for like 5 seconds .I already took it to the dealer twice,they said it's normal.Then I did some reading,alot of people are having the same problem.My question is jsut for peace of mind.Will there be any damage to the engine if it keeps doing that ?

Piston slap occurs in vehicles from most every manufacturer, not just GM. GM's piston slap may be a lttle more widespread, but I might debate that. Everything I have read about piston slap indicates there is no reliability/longevity issue to speak of with it. The biggest complaint is that it can be annoying. Here is one from a guy with a Pathfinder, you can read about it here:
http://townhall-talk.edmunds.com/WebX?14@268.53Y5dy15geS.0@.ef19330/817

It is MUCH more common with GM vehicles than with any other brand. GM just won't fix it. Case in pont, my '04 Ford Escape had it; not bad, but had it. Ford bought back my Escape last month because of it towards an '05 escape. GM won't do that unless threatened with an active lawsuit. Is it determental to the life of your truck/car? Well, the sound alone should be enough proof for anyone with an ounce of common sense to say "YES". It is more than an "annoyance". I did not pay 35K for a new truck to wake the neighbors in the morning with a clatter reminicent of a 6.2L diesel. It is wrong and if GM won't owe up to it then thay are WAY behind the other automakers in securing future buyers.

so this is in fact bad for the engine???

It's debateable, but most everything I have seen on engines with piston slap (not just GM) would lead one to believe that the engines with piston slap last just about as long as the ones that don't have it.

now would this be more common in a colder climate???

My guess... is the slap comes from the lack of oil in the engine at start up. So that said, It really shouldn't be more noticable in colder climate than warm other than it might last a little longer in cold weather due to thicker oil. However this is just my educated guess. I am one of the lucky one's. My truck does not do this, at least not more an a second or two. I also live in the upper midwest (cold winters).

Use Royal Purple or Amsoil or another good synthetic and say goodbye to dry starts.

actually,i'm using amsoil.But a heavier oil,10w-40...I'm going switch back to 5w-30.

piston slap is not due to a lack of oil as much as when the engine is cold the pistons are not as tightly in the bore as when the engine is warm. it goes away when combustion heats up the piston sufficiently to expand it into the bore. I think GM used pistons with short skirts in the vortecs, so when the piston is cold it can move around slightly

piston slap is not due to a lack of oil as much as when the engine is cold the pistons are not as tightly in the bore as when the engine is warm. it goes away when combustion heats up the piston sufficiently to expand it into the bore. I think GM used pistons with short skirts in the vortecs, so when the piston is cold it can move around slightly

if thats the case then its not that big of a problem......Right???

i havent heard of anything horrible happening cause of it. my 99 does it whenever its like 50 or below outside, and ive got 130,000 miles on it so far and still goin strong.

i havent heard of anything horrible happening cause of it. my 99 does it whenever its like 50 or below outside, and ive got 130,000 miles on it so far and still goin strong.

See?

my 96 does it and i have 98k on it and so does my venture and i have 100k on it. It is really just annoying, some say that it can score the cylinder wall, but I have seen absolutley no proof. Even if an engine fails that has piston slap, how often can that failure be attributed to the slap? probably never. Most of the time anyway.

i have heard of alot of trucks doing this and have not heard of any problems. i heard using different oils will help but nothing will actually cure the problem. i can't see how it would cause any problems since so many vehicles do this and the manufacturers dont do anything about it.

Both my 00's do it...... A Slverado 5.3(37k miles) and a LS1 Trans Am(24k miles) apart from it being a little annoying and embarassing at times, so far both are still going strong, but you can check this site out for more info:
http://www.pistonslap.com/

Both my 00's do it...... A Slverado 5.3(37k miles) and a LS1 Trans Am(24k miles) apart from it being a little annoying and embarassing at times, so far both are still going strong, but you can check this site out for more info:
http://www.pistonslap.com/


WOW very interestion information!! that sound clip is horrable and according to the article it does occur more often in the cold and it seems like gm did not fix the problem in the spring summer of 02 true?????

Here's another thing though,I have 83,000 miles on the truck.I bought it at 68,000 miles,last year or soo.Took it to the dealer twice ,they said it's normal in the repair list.Always had the slapping,but it seem to gotten worst when I put the 10w-40 in it.I don't have any engine problems or any other type of problems expect that engine slap.I'm going put 80 more dollars down and get back to 5w-30 amsoil.Then i'll give you guys an update about the slapping noise.


Also i have no smoke coming outta the tailpipe,so it's not leaking anything,nothing is dripping under the truck.I guess the true test would be if i can put 200,000 miles on the truck without anytype of engine problems.Then i guess GM would be right then.200'000 is like 7years away,So i'll get back to you on that.

Hmm.Just figure out that the guy selling me the amsoil was somewhat ripping me off....But then i found this..


https://www.amsoil.com/storefront/amk.aspx

You think that would do anything to help the slapping ?

Looks interesting... How much is it?

400 bucks...I don't think i can even install it.I was looking at the how someone with a 2001 silerado did it....Check it out..

https://www.amsoil.com/products/amsoiler/installation/2001chevy2500/index.aspx

check out the install on the suburban, too

Yeah i was just checking out that setup...Check this out...

https://www.amsoil.com/storefront/bf.aspx

interesting concept but can regular high performance oil filter do just with out all the extra?

I don't know,maybe someone with some extra money can throw some of that stuff in their truck and report back to us how it went...

I'm going make another thread about these amsoil concepts.Maybe someone would post something about it.

im sure there is a troop out there

WOW very interestion information!! that sound clip is horrable and according to the article it does occur more often in the cold and it seems like gm did not fix the problem in the spring summer of 02 true?????

As far as I know GM never did anything to try and fix it since they state "it's normal" and if they did admit it to be a problem, would open up a huge can of worms for themselves. It's definitly worse in cold weather.

thats gives me an Idea when I buy my truck ill be sure to test it when its cold outside

thats gives me an Idea when I buy my truck ill be sure to test it when its cold outside


Also make sure the truck's been sitting, preferably overnight.

You know what is weird ? This morning I was leaving for work and I didn't hear any of the piston slapping.I was running late soo I didn't really listen that good,but i'm going to check it tomorrow.

Alright, here's another one. A buddy of mine has a Miata. We parked his Miata here at my house for maybe an hour and then he got back in it. When he satrted it up after only letting it sit for about an hour, it had... PISTON SLAP! The car's only got ~80k on it, and he says it's pretty much always done it. Like I keep saying every car i've ever had did it, and it's a pretty common occurence and nothing I'd lose any sleep over.

Alright good news for me,Seems like the slapping is gone now,didn't even change the oil.It is about 70 degrees in the morning though.Anywho i'm happy it's gone.

I got a question if all the engines are the same why are there some with the problem and some that dont have it at all ??

I got a question if all the engines are the same why are there some with the problem and some that dont have it at all ??


Very simple, tolerances, manufacturing variability, low levels of repeatability, not one truck is made the same, because you can´t make all parts the same, and different parts at different tolerances will combine like ways you can´t imagine.

??? im still confused

??? im still confused
apparently...

so it was meant to be done???

I seriously doubt the noises you are hearing is piston slap. more than likely it is the rods rattling together until the oil pressure stabilizes them. Piston to cylinder clearances run very tight in the newer motors some less than .0015 Even GM won't miss far enough to hear piston slap. My wife had a 82 corvette once that rattled on startup. This motor was sealed up well used no oil and had no blowby, I put a set of main bearings in it without removing it from the car. The old bearings looked as good as the new ones and the startup rattle was still there with the new bearings. Just my .02 worth though.

I seriously doubt the noises you are hearing is piston slap. more than likely it is the rods rattling together until the oil pressure stabilizes them. Piston to cylinder clearances run very tight in the newer motors some less than .0015 Even GM won't miss far enough to hear piston slap. My wife had a 82 corvette once that rattled on startup. This motor was sealed up well used no oil and had no blowby, I put a set of main bearings in it without removing it from the car. The old bearings looked as good as the new ones and the startup rattle was still there with the new bearings. Just my .02 worth though.


Trust me, it's piston slap. There's no way it's rods since oil pressure builds immediatly on startup, these motors knock for a while till the pistons expand enough to tighten up the clearance. I do know what your talking about as I had a car that did what you describe, but that kind of knock is gone within a couple seconds at the worst.

for what its worth , this is my story with piston slap.


I had a 2002 silverado 5.3 Z71 bought it brand new, great truck but after 9000 miles it started slapping. It continued to get worse and at 30,000 miles it was slapping almost constantly. It was diagnoised by 5 diff. dealerships as piston slap, but GM wouldnt do a thing but give me a warranty.
When I first noticed it back at the 9000 mile mark i wasnt to concerned cause it would go away after a few seconds and never realy return through out the day. By the 30,000 mile mark it would slap at any start up and when driving you could hear it on deceleration or engine rev.
No other real problems though.
But since everyone was talking about piston slap and what i found on the web at www.pistonslap.com spooked me , I decided to trade it in on a new 04 Ford F-150.
this truck ended up having a new motor put in it at 3000 miles, not a misprint 3000 miles due to cam phaser problems and main baring failure. Ford bought it back in full. Fords service dept and corporate customer service was first rate for me.
But I couldnt live with a new truck that just had to have a new motor put in it plus there were some other issues.

So I decided on a new less expensive 05 Dodge Ram Hemi.

With my new Dodge I ended up back with piston slap, that started right away at 500 miles and a bunch of other loud tapping, and knocking noises. Took it in and was told by Dodge that all Hemis make noises and have piston slap, and worse then any chevy ive heard, but since it started so soon and was getting louder by the week, I didnt trust the dodge drive train quality. My Dodge had way too many other problems also .

So I am back with a brand new 05 silverado Z71 5.3 aluminum block and so happy to be back with GM. 1500 miles and no sounds and after all ive been through with the other 2 trucks even if it develops piston slap ill try and deal with it, cause in my opinion GM is better then the Ford and Dodge. (Just my opinion from my experiences) .

My neighbors 01 Z71 just turned 98000 miles and has had piston slap since around 15000 miles, is still running strong, and my other friend has 130,000 HARD miles on his 01 with med loud piston slap but still runs great, im pretty convinced it wont kill the motor.

I actualy wish I never got rid of my original 02 Z71 I was just getting used to the piston slap. It would have saved me some money too.

Just my story, hope it makes some of you feel better about your trucks and experiences.

s

You should try amsoil,it does work i guess,I'm going have to went until it gets cold again to make sure it went away.

But yeah,that's what scared me too,pistonslap.com.I

for what its worth , this is my story with piston slap.


I had a 2002 silverado 5.3 Z71 bought it brand new, great truck but after 9000 miles it started slapping. It continued to get worse and at 30,000 miles it was slapping almost constantly. It was diagnoised by 5 diff. dealerships as piston slap, but GM wouldnt do a thing but give me a warranty.
When I first noticed it back at the 9000 mile mark i wasnt to concerned cause it would go away after a few seconds and never realy return through out the day. By the 30,000 mile mark it would slap at any start up and when driving you could hear it on deceleration or engine rev.
No other real problems though.
But since everyone was talking about piston slap and what i found on the web at www.pistonslap.com spooked me , I decided to trade it in on a new 04 Ford F-150.
this truck ended up having a new motor put in it at 3000 miles, not a misprint 3000 miles due to cam phaser problems and main baring failure. Ford bought it back in full. Fords service dept and corporate customer service was first rate for me.
But I couldnt live with a new truck that just had to have a new motor put in it plus there were some other issues.

So I decided on a new less expensive 05 Dodge Ram Hemi.

With my new Dodge I ended up back with piston slap, that started right away at 500 miles and a bunch of other loud tapping, and knocking noises. Took it in and was told by Dodge that all Hemis make noises and have piston slap, and worse then any chevy ive heard, but since it started so soon and was getting louder by the week, I didnt trust the dodge drive train quality. My Dodge had way too many other problems also .

So I am back with a brand new 05 silverado Z71 5.3 aluminum block and so happy to be back with GM. 1500 miles and no sounds and after all ive been through with the other 2 trucks even if it develops piston slap ill try and deal with it, cause in my opinion GM is better then the Ford and Dodge. (Just my opinion from my experiences) .

My neighbors 01 Z71 just turned 98000 miles and has had piston slap since around 15000 miles, is still running strong, and my other friend has 130,000 HARD miles on his 01 with med loud piston slap but still runs great, im pretty convinced it wont kill the motor.

I actualy wish I never got rid of my original 02 Z71 I was just getting used to the piston slap. It would have saved me some money too.

Just my story, hope it makes some of you feel better about your trucks and experiences.

s


wow one hell of a story man but is there some sort of way to know if its coming or if your more at risk ie: a specifc year??? specific miles type of oil when you bought your truck,vin, production date, location there just has to be something in common that gm wont say to protect sales in a other wise competive enviroment...... something???

wow one hell of a story man but is there some sort of way to know if its coming or if your more at risk ie: a specifc year??? specific miles type of oil when you bought your truck,vin, production date, location there just has to be something in common that gm wont say to protect sales in a other wise competive enviroment...... something???

I think the bottom line is that they all have problems, kenwood guy, and you should get whichever truck you feel suits you best

as for specific clues on what to expect.

all I can say is from my own personal knowlege re piston slap in GM trucks is that 1999 through 2002 were the worst. it usualy starts in the 7000 to 15000 mile range. From what I understand in 2003 they started experimenting with teflon coated pistons and 04 and 05 they went to aluminum blocks with steel sleeves and coated pistons. Personaly I havent heard anyone I know with an 04 0r 05 having piston slap.

As for oil in my 02 I started using Mobil 1 5w30 and a mobil 1 oil filter it seemed to quiet it down just a slight amount. I tried alot of oils to see if it would make a difference, and all i know is the thicker the oil for my truck the worse and harder the piston slap sounded. I know there are those who will dissagree with me and i was convinced also that by using 10w40 it would quiet it, I tried it for a few hours ,but it didnt, it was worse. So I just stayed with Mobil 1 5w30. I never tried a 5w20 weight oil to see what would happen.

As for vin # and other misc. factors, i personaly dont think it makes any difference, i think all 99-02's have a certain degree of piston slap. In fact i have never heard one that falls with in those years that didnt have some sort of piston slap, just my experience.
But as i said before after going around the block and experiencing the others im glad to be back with GM.

Im personaly hoping that with the aluminum block now, that the whole motor will expand and contract from temp changes at the same pace and with the steel sleeves and coated pistons that maybe i wont ever experience piston slap with this truck , but you never know.

s

as for specific clues on what to expect.

all I can say is from my own personal knowlege re piston slap in GM trucks is that 1999 through 2002 were the worst. it usualy starts in the 7000 to 15000 mile range. From what I understand in 2003 they started experimenting with teflon coated pistons and 04 and 05 they went to aluminum blocks with steel sleeves and coated pistons. Personaly I havent heard anyone I know with an 04 0r 05 having piston slap.

As for oil in my 02 I started using Mobil 1 5w30 and a mobil 1 oil filter it seemed to quiet it down just a slight amount. I tried alot of oils to see if it would make a difference, and all i know is the thicker the oil for my truck the worse and harder the piston slap sounded. I know there are those who will dissagree with me and i was convinced also that by using 10w40 it would quiet it, I tried it for a few hours ,but it didnt, it was worse. So I just stayed with Mobil 1 5w30. I never tried a 5w20 weight oil to see what would happen.

As for vin # and other misc. factors, i personaly dont think it makes any difference, i think all 99-02's have a certain degree of piston slap. In fact i have never heard one that falls with in those years that didnt have some sort of piston slap, just my experience.
But as i said before after going around the block and experiencing the others im glad to be back with GM.

Im personaly hoping that with the aluminum block now, that the whole motor will expand and contract from temp changes at the same pace and with the steel sleeves and coated pistons that maybe i wont ever experience piston slap with this truck , but you never know.

s

You know, I've never fully understood how a manufacturer can successfully mate aluminum heads to an iron block, because aluminum and iron have such completely differrent rates of expansion and contraction.

What year truck do you have, Suprteck?

You know, I've never fully understood how a manufacturer can successfully mate aluminum heads to an iron block, because aluminum and iron have such completely differrent rates of expansion and contraction.

What year truck do you have, Suprteck?


I agree.

My old one was an 2002 5.3 now I have a 2005. The 02 5.3 was a cast iron block with aluminum heads but I think in 04 GM made the switch and went with an aluminum block for the light duty trucks. I know my 05 has an aluminum block with steel cylinder sleeves. I realy like that they went in this direction.

My dads 99 3/4 ton will do it sometimes when it's cool in the morning and he just starts it up, you'll notice that the oil does have an effect on it cuz his will do it worse when your nearing the oil change. It only does it for a few seconds though, most I've ever heard it go for is maybe a minute. I think it has about 85,000 on it now and he uses 10w-40 Valvoline. Only lemon he has on his truck is the damn fuel pressure regulator, it's gone out twice since we've gotten it, btw, anybody know where we can get those online for a good price??

does anyone know about castrol gtx start up motor oil ???

Alright I took the truck to the dealership again for them to check out the transmission and I added about the piston slap.Anyways,about the piston slap he said once he check out the transmission he will give me a paper and I will call GM(chevy) about the piston slap.This is the 3rd time I took it for the dealership.When i get the paper all i'm going ask them is to cover the engine up till 200,000 miles,What do you guys think? You think they will do it ? 200,000 miles seems fair though.Engine these days should last till 250,000 miles.


*** edit....also what he said why it does that because they made the cylinders too short in those years of the engine.They was making a fix for it he said however once they figure out it doesn't hurt the engine they didn't worry about it.

I can't beleave you guys don't know about the secret warrintee GM has on piston slap..... trust me...it's there.. if you have piston slap on a Silverado or GM pickup/SUV in the years of 1999 to 2003 take it to the dealer and make a complaint....they will look it up....and fix the problem... Right now there is a Class Action Suit against GM for just that problem...so do it NOW ! before the suit is settled... I think the secret warintee will go away once the suit is settled.....

I have a 2001 Silverado with piston slap...and thats what I am doing.....

Now the problem.... Piston slap is caused by skirt wear/ cracked skirts/piston pin offsets (position where pin is cast to offset piston rocking) I kinda think that the offset is the problem...why would only the truck engines slap ? and not the car engines ? (different offset) It does not cause cylinder bore wear....and once the pistons have warmed the skirts expand and the rocking of the pistons stops and the noise goes away...
IT IS A MANUFACTURING DEFECT and it is covered by a special warintee that they don't like to admit as the cure is to replace the pistons with pistons with a stroonger skirt... (ie...forged pistons)

Turst me, I taught Auto Mechanics in a Jr. College for 30 years and I am a trained GM mechanic and a ASE Certified Master...

Joel Rapose

I have a 2001 Silverado with piston slap...and thats what I am doing.....


Turst me, I taught Auto Mechanics in a Jr. College for 30 years and I am a trained GM mechanic and a ASE Certified Master...

Joel Rapose

START A NEW POSTING ON YOUR PLAN OF ATTACK !

I am sure there will be many interested in your success/failure...so If we don't here from you again It will be failure....

unless you get a new engine they will screw it up so bad you will wish this was never done...just to teach you a lesson...

The Class Action Suit...options are

1. if you bought a extended warintee you will recieve a refund
or
2. if you had motor work related to the pistons you will recieve a refund on the work done.
or
3. if you had motor work related to the camshaft you will recieve a refund on that work done.

and there is one other....I just can't remember... but I am sure it is online.. I think the closing date for comment is end of next month..

Joel

I do not think these options are fair....

As piston slap usually does not show up until later in engine life.... mine started at 80,000 and knowing it was not damaging the motor I just learned to live with it.....

A fair deal would be to give everyone with the affected vehicles an extended motor warintee....something like 200k miles..... as the problem may not become serious until 100k or even more...way beyond any normal vehicle warintee.

But is it worth spending a day in LA in court...to be heard...and even then possibly not change anything...... the only one that makes money out of this court case is the guy that brought it...($7500) and the lawyers (1.7mil)
the actual folks with the trucks....get.... screwed again..

Joel (old fart)

First of all can anyone post or find any info info where the suit was settled in the plaintiffs favor, second this thread is way too old, I will leave it open till I see evidence that this is ongoing or settled. I am a retired GM employee and have intimate inside info and there is no special hidden warrantee to replace pistons. On a case to case basis or under warrantee it may be considered if accompanied by high oil consumption, but right or wrong GM is not fixing these issues. Just to add GM is not the only manufacurer with this issue, including foreign makes. There are many cases where the owner of an affected vehicle went to BBB arbitration and won and GM took the vehicles back or other forms of settlement were reached, again on a case to case basis. Check this tsb link. http://www.pistonslap.com/tsb/010601022.pdf

I do not think these options are fair....

As piston slap usually does not show up until later in engine life.... mine started at 80,000 and knowing it was not damaging the motor I just learned to live with it.....
)

I had this occur in my 2000 5.3L silverado.. GM stated carbon deposits CAN cause this to be an issue,as well as poorly sized pistons/bore..

In MY case it apears to be the carbon that caused my noise at around 36,000mi...just when the warrantee ended...HA! HA!...

So I used marvel mystrey oil in the fuel and over a few hundred miles the problem reduced alot...now whenever it starts again I repeat this cure...

Because this is variable in all engines it is impossible to say this will reduce or eliminate your problem...

this mystrey oil loosens the carbon on the compression rings and the pistons don't rock as much....

It's a real easy suit to look up.... it's Silverado Piston Slap... and google will pull it up .... GM has sent letters to everyone that bought a 1999-2003 Silverado pickup... look it up yourself...

Joel

Both my 70k 2000 silverado 5.3 and my 30k 2000 Trans am have piston slap and it's kinda embarassing to start em up with people around, but so far hasn't hurt either engine, not that it won't eventually although this "secret warranty" is worth looking into if it is in fact, fact.

As much as it kills me to post in a 4 year old thread....

My 02 silverado 4.8 had piston slap @ 500 miles. I fought HARD even talking to regional reps and never got them to fix it for free. Maybe I was too 'early' to get the secret free stuff; but it didn't happen.

Now; my truck is 8 years old (bought in 01) and with more than 150,000 miles on it sounds exactly like it did with 500 miles. hasn't gotten any worse.. and I haven't spent the $ to make it better.

I don't think it 'hurts' engines; but DOES annoy me and like Dano says.. Yes; it sucks when someone else turns toward me when I start my truck. I KNOW; it's loud.

-TD

Well, I bought my truck (2000 5.3 Ext. Cab LB 4WD) in 2005 with 104,000 miles on it, now i'm closing in on 180,000 miles, it had the piston slap from day 1 and it still does. I'm not worried about it at all, I still love this truck !

Bert

http://tinypic.com/ei2g51