Lifter noise on 2002 Coupe

[theplayer]

Sounds like I am in for a treat from the sound of your story. They did mention putting new pistons in my car. I don't want them to open my engine though because once that happens it is never the same. You would think GM would take care of a corvette owner. Sounds like you did all you could do with GM.

 

[gonetobama13]

Wow, this lifter and/or pre-ignition noise problem in the C5's has really become an issue lately and has taken up a lot of thread space. Along with it has come diagnoses and solutions from a number of people, sometimes contradictory. I have 2500 miles on my '04 with no problems yet. I hope it stays that way, otherwise I'm not sure what I'd do. But then, that's the great thing about the CAC in that it's members give you so many suggestions to work with. Keep those ideas coming!

John K.

 

[admiralveneer]

Piston Slap

My 2001 coupe has had this noise ever since I got it... I had a 97 and never noticed it... When I first got my 01, brand new... it wasn't too bad... I only really started to notice it the 2nd winter... that tapping noise just seemed to last longer and longer into the drive... initially it was only like a minute or two...then 5... and now it takes like 10 to 15 minutes before it diminishes to the point where you don't notice it... of course now that I'm listenening for it.. I can hear it all the time.... I remember last year... when I got my oil changed... I thought that would perhaps cure the problem.. in fact I was afraid I'd waited too long between changes... even though the oil life remain was still showing 15%... but after the oil change... it was just the same.. quite loud upon cold start... and now .. a year later.. and almost off of warranty... It's gotten a bit worse...
I remember about a year ago .. I found one article online.. referring to a 'normal' piston slap sound... that was present in the 01 model, it said the same thing... that it wasn't a wear issue... and that it wouldn't cause any problem. So I sorta just dropped it...

But then... Sorry If I'm being too wordy... when I was picking up a Rx at the Walgreens drive thru... the women asked me if something was loose on my car ?... Which of course ****ed me off... and I thought... I gotta have the dealer check it out.. so after my last oil change... a couple of weeks ago... I called and talked to the service guy at our local chevy dealer... He does all the corvettes... and told him of the recall notice... the one about the cut oil ring... and he said to bring it in.. so they could let it sit overnight... and start it cold... well the next day they called.. and he said it wasn't that oil ring thing... but that it was a carbon build up.... specifically.. when they turned off the number 1 cylinder.. the noise went completely away... so the 'de-carbonized' the entire engine... it had to sit 8 hours... and then they'd put it back together.. let it sit overnight.. and try it again... Well... next day they call back.. and said that it was better, but not gone... when the turned off the number 1 cylinder.. it completely went away still... So then he went on to explain the piston slap phenomenon... and give me the 'it won't do any damage' schpeel...(sp?) and the only way to fix it completely would be to take the engine apart and replace the piston/cylinder... I asked.. 'would this fix the problem ?'.. and he said yes... so I said fine... that's why I brought it in... and since I already had a loaner... go for it... and esp since my warranty is out in November !!!
Well.... today... the service manager guy calls me , as I had asked to be kept abreast of how long this would take... and at the time he said it depended on what they found when they opened it up.... so anyway... he calls me today... and says that they ordered me a new engine.. and that it would be in next week, and that the guy should have it in by next Thursday or Friday... to which I replied... 'OH... they had to get a whole new engine ???' and he said yeah... to which I started to ask... 'Is that OK' meaning to me.. with my severe deficit in the automotive/mechanical arts... isn't putting a whole new engine in worse than just replacing a part or two..... But he must have thought I was going to ask whether it was covered... because he just replied 'yeah... it'll be covered under warranty'...
So, now listening to this discussion... I feel that the whole new engine route was actually a better thing... Here, I thought just replacing the pistons would be a less severe operation... show's what the hell I know about engines... but I'm not sure why they went to the whole new engine thing... I guess I'll let you guys know what happens next week.. if I get the car back...

So I'd push for a whole new engine... seems it should be possible...

Later...

Good Luck...

 

[johnl]

I don't want them to open my engine though because once that happens it is never the same.

You may be right. I have a buddy who had his done. His 2001 puts 345HP to the ground after. Before it was 305HP on the dyno.

 

[modman]

piston slap

got a 2002 automatic with 16k on it and I hear the same tapping noise at first start in the mornings. It goes away after a couple of minutes. My gut says it could be lifters, but I agree that it should quiet down fairly quickly on startup if that is the case. I talked a little about this with 69myway as his wife has a 2000. He did not seem to be too concerned about any impending doom with either his motor or mine. I think Lucky7's81 is probably more current on this issue. If it turns out that piston slap is causing severe degradation in my motor then I think that GM can be made to do right by their customers (me). I wouldn't expect any manager to readily offer up a new motor to any car owner. They are going to try to mitigate their losses. That's the business side to anything. I don't even worry about any kind of warranty issues. That's what you pay lawyers to worry about. It will be interesting to see how all this develops. I don't have any intention of getting rid of my vette and I will drive it daily. Guess what ....the motor will die one day anyway. I'm not made of money but I try to think rational about stuff like this. Hope the noise does not get louder for me, but my thinking is that at 16k miles my powerplant is pretty strong (like new) and I will see what happens. I have no smoke and burn 93 octane only.
Really enjoy the info sharing at CAC.

 

[theplayer]

admiralveneer:
Sounds like you got treated right. There must have been some bad damage in that #1 cyclinder for them to just say "new engine". Mine quits knocking when #4 and #7 are off. It takes about 5 minutes after cold start for the knock to go away and I only have 9200 miles on my car. So I can expect it to get worse I guess. Keep me informed on your car. So you let them take your motor apart before they offered a new engine? See if you can find out how bad the damge was on the old engine. Also, are you getting a new 2004 complete engine or just a new long block? I am about to go this this process on my car. I have to meet with the service manager sometime to talk about options because the carbon clean did not help mine out. That mean its piston slap.

 

[atmmac]

Thats really weird guys my 97s motor has been good but with 11,00 miles it should be. Your cars should be making no noise as they are NEW dont settly for anything less than a job done right and make sure you use all of your resources GM can be tough. I found out with steering column lock twice in one month. Player i would havem pull it apart they will probably give you a new motor too! I want to wish you guys all Good Luck!

 

[theplayer]

Today I have to make the decision about letting the dealer open up my motor. I know it’s the only way for them to see what’s wrong or if there is any damage but it still sucks. Once they do that there’s no turning back. I’ll either have to have new pistons or a new engine put in it. Dealer said they would have to pull the pistons and mic them and the cylinders to see if there is a tolerance issue. I don’t know how they do it because the cylinder is round and the piston is like an oval. I know that’s a major deal but it’s the only way I can get it fixed. I just hope that my cylinders are scored or have sign of wear so they will give me a new engine like they did with admiralveneer. I’m glad I found one guy that has had the same problem and has gotten it fixed. It’s probably only 1 out of 500 that have this problem though. If my knock would go away after 10-15 seconds after start I wouldn’t worry, but when it does it for 4 to 5 minutes you have to think something’s wrong.

 

[theplayer]

Johnl: Are you saying that after your friend got his pistons replaced his hp went from 305 to 345?

 

[cntrhub]

admiralveneer,
You know they had to get an OK from the district manager and he (the DM) had to get an OK from the higher ups. They know there's a problem without admitting it. Hopefully that engine has the problem solved by redesign and all is well.
theplayer,
The piston "skirt" is the measurement taken to determine the clearance between the piston wall and the widest part of the piston... i.e. = skirt clearance.
When you start out boring a cylinder, the cutting bit will expand from heat. So, say you start cold at the top of the top of the block and then by the time you're down at the bottom of the cylinder wall, the cutting bit is taking out a little more than when it started at the top because the bit grew from heat. Look at it like (an upside down) V configuration. Just a theory to think about.

 

[theplayer]

Update: Dealer ordered 8 new pistons for my car due to GM recommendations. I really don't want the new pistons fix but I don't fell like I have enough leverage yet to say new engine. Hopefully when they open up the engine the cylinders will have signs of damage. That's the only way to get the new engine. Dealer siad that new pistons wouldn't effect resale of my car but I didn't expect him to say it would anyway. He also said the usually use the old rings with the new pistons. That was a concern of mine that I am going to have to find out more about. I would think new rings since there new pistons.

 

[cntrhub]

That's just about typical of a bad call if I ever heard one. Here you have a used set of rings going on a new set of pistons. You know the mechanic won't take the time to clean the carbon behind the inside rings. And the mechanic might not have a dial bore gauge to check for taper. How about finding the best piston size for each cylinder bore? He'll just R&R the rings, pick up any piston, and install it as fast as possible just to get the job done. Now you have these heat cycled rings that will be bent and distorted by removal.....a possibility. Will he set each ring on a surface plate and make sure they are flat? Doubt it. Now the transfer of those old rings onto the new pistons. Will they spin freely in the ring grooves? I'm almost certain there will be fine scratch lines in the bore from debris the air cleaner couldn't capture. What about ring seal now? The variable is the tighter pistons will form a completely different ring seal angle on an already beaded in set of used rings. I bet that puppy smokes all day long.
Let them put the old rings back on. If it smokes like a California mountain ridge, maybe you have a chance at a new engine. Say nothing theplayer.

 

[CFour]

This is known as "stack up" Its where a slightly undersized piston is dropped into a slightly larger then normal bore. Hence you have a cold start up knock until the metal expands and the sound stops. Sometimes this can happen due to a slightly clogged injector as well. They must "know" something. Maybe some motors were over bored at the factory. They will install very slightly larger pistons in there places this should fix your problem.

 

[theplayer]

Yes they know something is wrong. They seem to think that I have undersized pistons in 4 and 7. Once they open it up they will mic all the cylinders. If they are abnormal I will cry new engine.

 

[admiralveneer]

Update...

Sorry it's been awhile... I've been a bit busy... Well after about 10 days... I got my car back with the new engine last week.
I drove it home and man... I didn't realize how loud mine had gotten... when I picked it up .. I attempted to ask them about the new engine... but as usual.. it seems like you can never get anyone that knows what the hell they're talking about... I wanted to find out when the new engine they put in was produced... at least some sort of serial number I could look up... or something... but all they could tell me was that it was "a whole new engine.... and the GM part number.. which was 88984271 -- ENGYLS1GW...
So that kinda ircked me... but I figured they didn't give me any hassle... so I was pretty nice about it all... The other thing that sorta made me mad was that they said the new engine would only have 12 months/12,000 mile warranty... which seemed to me like it ought to have 3 yr / 36,000 miles... since if it went into a new car.. that's what it would have... but again... THey gave me a whole new engine... so I was fairly nice about the whole thing...

Now ... did you sense something more to the story was coming.. well your right... it started when I was driving the car the next day... I kept thinking I heard the 'ticking noise' again... but not right away.... only after driving the car a while... like 10 or 15 minutes... I'd be slowing down... or coasting... then starting to accelerate... and think I'd hear the same frickin sound... now it wasn't as bad as mine was... but it reminded me of what my car sounded like when it was new.... So I thought I was nuts... here it is... a whole new engine... and I think I'm hearing that sound again... what the hell. ?? Well.. the last 3 to 4 days.. I've been really paying attention... and here's the results...
The engine is fine at start up... when it's cold.. it's silent... which explains why I didn't notice it immediately when I picked the car up... and only drove like 15 minutes to our house... but once the temp of the engine gets to like 190 or so... you start to hear a ticking noise coming from the engine... at like 1300 rpm's ... it's at its loudest.. then as you accelerate... it goes away... so you don't notice it.... and if you let the engine slow... it just disappears into the idling engine noise... belt noise.. etc.... well at first I thought... maybe I'm just listening too close to the engine now... maybe all LS1's sound this way.. and yesterday... I was driving the car around for about 40 minutes... and I swear the noise diminished a bit... although when I was driving through the parking lot... only going like 5 miles an hour... you can hear it pretty good... it just doesn't sound right... it's like you give it some gas... and you hear a helicopter sound.... tick - tick - tick -...
So I called 1-800 chevy number... to inquire about the warranty... and she confirmed that it was only a year warranty... but said after talking to whoever it was she talked to ... that GM thought it unlikely that I'd have the same problem with the new engine... but yet she didn't really give me any hard data as to why that would be the case... which was my purpose for calling... when I told her I was hearing the noise again... much like my car was when new... she said to let the dealer hear the engine... and go from there... but that GM would stand behind me..
SO... any thoughts... ??

Does anyone else... esp anyone with a 2003 hear any tapping noise around 1300 rpms...
From what I understand.. the new design of the LS1... they use a smaller tolerance.. smaller clearance in the cylinders... and a stronger spring... and that the new pistons are polymer coated... So I'm thinking that if this is a new engine... that should be the case...

maybe I'm just hearing some other engine noise.. since it's mainly at a certain rpm... maybe something it rattling...

Well... anyway... I called the dealer.. and I'm gonna go talk to the actual guy that works on the vettes there... and have him drive with me and listen to it... so I'll let you know what they say...
So far.. the dealer has been great.. so I gotta play it nice... but I anxious to hear what he thinks...

As far as everything else goes... the car seemed to drive just like new.... and getting a whole new engine.. esp since my car was almost 3 years old... is a sweet deal... my only other complaint was that apparently they left my windows open the whole 10 days the car was in the shop... so my car smells like auto shop inside... #@($)... but that can be fixed.

as far as what they saw... since I never talked to the actual mechanic yet... all I can go by is the description on the paper work which said the following...
Found #1 cylinder out of round and piston wall scored
T.A.C. case 685-5092
DecarobonM engine per T.A.C. and R/R engine found piston slap
on #1 replace engine

So I'll write back after monday... should be interesting...

It's just a dilemma... because it's not that the noise now is so awful...although now that I'm listening for it... it's annoying as hell... but the main thing is knowing that that's how my car started when it was new... and after a year.. it got worse... and I asked about it.. and they said it was 'normal'... and I let it go... and it got worse... and finally after 3 years... it really sounded like something was clanging in the engine... ...
so if I let it go now... I've only got 1 year... so if it takes 2 or 3 for it to get bad again... then I'm screwed... SO now I feel like I don't have any choice... and I've got to pursue it till I'm sure it's perfect...
It's funny actually that after the decarb procedure.. even then the manager said... 'well.. to fix it we'd have to totally take apart the engine... almost as if to scare me... (which luckily ,,, I don't know that much about car engines.. so I didn't know enough to think that was a bad thing... ignorance is bliss),, and we won't know what we have to do until we open it up... .then he added that to leave it like it was.. 'wouldn't hurt anything... and it wasn't a wear issue'
which seems really strange since it says the cyclinder was out of round.. and the wall was scored... hmmmm... isn't that wear ????
So to theplayer... I hope you have them take apart the engine... because in my opinion.. they're using that 'take apart the engine' crap as a way to scare people from doing anything about it... because I think they know what they're gonna find when they open it up... namely that it can't be fixed ... and a new engine is needed...
I just hope that the new engines have fixed the problem... why if it's so rare have I got 2 engines... hmm....

I'll let you know.... keep in touch.... and good luck.!!!

 

[c4vette92]

i have a 2003 ae coupe with 2400 miles on the car. when i start the car i have a low tapping noise from the engine till it warms up, my 2000 coupe did the same thing. i think it goes away when the car warms up. today i'll take the car out and listen at 1300 rpm when the engine is at operating temp and let you know.

 

[c4vette92]

i had the car out today and when the engine was at normal operating temps i did not have any tapping sound at any rpm.
i did pay attention around the 1300 rpm area and all was normal.

the sound you might be hearing could be coming from the exhaust manifold, just a thought, stw

 

[theplayer]

admiralveneer:
Thanks for all the information. Your story sounds just like mine. They went through the same steps with me. They order new pistons before even opening the engine up. They said they would have to replace the pistons but if the cylinders were damaged or out of tolerance a new engine would be in order. I just hope they find something like that because I would rather have a new engine than a rebuilt one. They have all the parts and I should be taking it in this week.
That’s weird about your new engine noise. I never heard my knock after it warmed up. This might be a different noise. It could be a number of things. Something could be loose from them putting a new engine in it. It could be something simple like that. There is a TSB out though that talks about a knock on new engine after warm up. Here’s the link http://www.rjsmith.com/gm-1206539.html
It’s probably not pistons slap because you’re hearing it after it warms up. Piston slap goes away after warm up. This sounds like another engine noise.

 

[tt-rexx]

I almost bought a red z06 that had this & excessive oil use problem. It was a lemon law buyback. I decided to pass though, because the lemon title stayed w/ the car (even if fixed by dealer) and value would have gone down.

riding around in 1st or 2nd gear caused oil to blow by the piston rings on 6 speeds never happened on auto.needed bigger rings this is per gm

 

[froggy47]

Interesting,

It's just way too much fun to nail it in 1st & 2nd :s

I do in my LT4 - no oil usage problems. Even after 6 or 8 autox runs it's right where I set it to begin. I use maybe 1/2 qt in 4,000 miles.

I keep it topped off & check often.