five7kid

iTrader: (14)

First, I haven't heard anything like it with my 2000 LS1/T56 (reportedly 55k miles on the engine/trans) swap. Admittedly, a lot of the time with it has been with loud exhaust, but I haven't heard a hint of it, even for the short time that it had full exhaust on it (the driveshaft and torque arm letting go at launch DID make a lot of noise, though).

Now, the reportedly 87k 2000 LS1/4L60E is a different story. I really didn't notice anything at first, when the weather was warmer and it was being driven mostly at the track (meaning, warmed up). But, as the weather has gotten colder, the noise is much more pronounced. It sounds like the engine is ready to come apart when first started up (okay, perhaps that's a little bit of an exaggeration), but it doesn't seem to completely go away after a 10 mile drive (one-way to work or home) like I typically hear with regard to piston slap. Also, it doesn't sound like all 8 pistons, but more like one that's complaining.

Now, why would I be concerned, when I've heard about the issue long before I got either swap running? Well, mostly this:



... and this:



There wasn't any obvious damage to the valves, but I didn't pull apart the 853 heads that I removed, and put shaved 317 back on. Two other pistons were kissed, but without any other apparent damage (pushrods straight, for example)

One other possible factor: This lifter...



...that went with the bent pushrod, was replaced with an O'Reilly replacement lifter. Maybe what I'm really hearing is the lifter, but the car seems to run just fine. Based on the sound, though, it sounds more like an every-revolution noise, rather than an every-other-revolution lifter noise.

I'll probably be pulling the engine soon to fix a rear oil leak (not sure at this point if it's pan or rear main, but either way, pulling the engine is most likely required to get it fixed), so that would be the time to check out whatever else could possibly be causing this.

I don't want to chase my tail on a non-problem, but I also don't want to ignore something that could wipe out the engine.

five7kid

iTrader: (14)

This is the #3 piston, which is what I mean by "kissed" - much lighter impression. The other, #4 I believe, was similar.

one92rs

iTrader: (5)

if the valve even ever so slightly kissed the piston then pull the heads. take the valve out and roll it on a table. it is bent. sorry but it is. i had less of a hit on the piston and it was bent. please pull it out and go thru them. how much were they shaved. what cam.

five7kid

iTrader: (14)

Read again - the valves that hit the pistons were in the stock 853 heads. Those heads were removed, never disassembled. They are now sitting in the storage unit.

The heads that are currently on the car are 317's that were completely disassembled, everything checked out, shaved .030", put back together with L92 springs. This was done by a pro, not me.

Cam is stock Camaro 2000 LS1.

Orr89RocZ

iTrader: (20)

Local guy asked this question about possible "knocking" like sounds and everyone posted "its just cold piston slap". He even had a video of it.

Few days later, the motor let go.... I told him to look into it as I didnt believe it was piston slap. oh well... My 101K ls1 doesnt make a sound when cold

Good that you looked into this

five7kid

iTrader: (14)

I think I'm going to get the car home tonight, and start driving the truck until this engine is out, apart, checked over through-and-through, and reinstalled.

Maybe the LS6 cam that was given to me will go back in. Perhaps, if the LS1 is FUBAR, the LQ4 shortblock, intended for the '57, will go back in with it.

five7kid

iTrader: (14)

BTW, those pictures were taken back in August, while I was preparing the LS1/4L60E for installation. I did post them here. Nobody suggested there might be hidden damage. I looked up at the pistons & cylinder walls as much as possible without disassembly and didn't see anything amiss.

While the oil pan was off, I did shake each rod big-end, but didn't pull the caps. They all felt very snug. I had recent experience with not-snug.

Oh, the recent "not-snug" experience (396) had completely different symptoms - quiet when cold, noisy when hot. "Normal" oil pressure when cold, reduced oil pressure when hot.

Forgot to mention, oil pressure with the LS1 is fine. I did install a Melling oil pump while everything was apart back in August. And a new timing set (although not an LS2 set).

five7kid

iTrader: (14)

What "let go"?

Orr89RocZ

iTrader: (20)

Its funny because I looked for that thread on the forum it was posted and its no longer there. I searched and I think it was deleted based on all the bad advice. I think it was a bearing failure...either rod or main. It was actually light knocking and not piston slap. He lost all oil pressure and it became very loud knock.

five7kid

iTrader: (14)

I started it up after work and opened up the hood. The noise seems to be coming from the driver side (which is where #5 is). After getting home (more like 12 miles, combo stop & go and highway), I checked again - general "happy sounds", nothing distinct from one side or the other.

It's definitely "harder" sounding than valvetrain noises, at least what I'm used to. Sounds more like a rod, but like I said, oil pressure is fine.

I'll make it a point to check it out more when I get the engine out. I suspect the wrist pin or skirt was hurt on that #5. More likely skirt, since it seems to quiet down with temperature.

Jim85IROC

iTrader: (2)

That part that concerns me was your comment about it lasting about 10 minutes. My father's old 2000 GMC (stock 5.3) had the cold start "piston slap" and it lasted all of about 3 seconds even on the coldest day. I think you're hearing something else, perhaps that lifter.

five7kid

iTrader: (14)

It sounds "deeper" than a lifter, but I'm fairly new to this LS1 gig, so I wouldn't discount it. I didn't mention it in this thread, but the cam lobe was a bit scuffed by the failed lifter. I smoothed it off with a diamond stone. I would think, though, if that was the problem, that it would be noisy cold or hot. Certainly something to check when the engine is out. Just might put one of the LQ4 lifters back in place when it goes back together (it's probably going to get a full set of LS7 lifters).

A 3-second noise sounds more like a lifter. Takes longer than that for a piston to warm up and expand. Lifters can be "dry" at start-up and pump up when oil starts flowing.

Pocket

iTrader: (24)

If the skirt was compromised then you should have seen very clear scoring on the cyl walls when viewed from below (checking the rod mains)

Might just be a few more lifters failing. The engine was dogged pretty hard

Klortho

This is the closest that I can find that you can hear the piston slap, my '98 has it with almost 190k miles on it.

http://www.youtube.com/watch?v=Mw9R-...eature=related

cam-

My old 01 4.8 Sieera had BAD piston slap but I drove the **** out of that thing and it never failed me. 235k miles on it when I sold it.

As for the pistons kisses? My 99 LS1 that I sold had those on every piston ( milled heads and 7K RPM daily hehehe ) Anyways we checked it out and put new heads on it and its still screaming 7K Daily in the new owners car without issue. I say run it. FWIW That LS1 had loud piston slap noises when it was cold too but never consumed oil or had compression issues so I wouldnt worry much.

I also recall over at tech when there were loads of threads complaining about piston slap and there were plenty of vids posted that sounded REAL bad but GM had not warrantied any of them as it was only a nuisance not a real problem that could lead to failure.

$750 L98

Piston slap on BOTH of my cars is fine during the summer, but worse in the winter. One has over 60k and was like that since I've owned it, the other I've put nearly 4k on (has 100k miles) it does it and still runs fine. I always let it warm up to at least 120* before I drive off.

It's a combination of the rates of expansion, short piston skirts, and lack of piston to bore matching from the factory. GM has come out several times and said that due to the design of the piston skirt, and the materials used to make them, piston slap is inevitable. Some have it from the factory, others have it 60-100k down the road. (newer pistons/skirts are supposed to address this, LS2/LS3 etc don't seem as bad)

I can show you pics of what it does to the bore after 60-100k if you want, my 6.0 has some scuffing from it.

I am in no way saying to ignore it or neglect the sounds, but mine has been that way for a good long while. There is definitely a difference between rod knock and piston slap though.

Even my late LT1 had piston slap.

88 350 tpi formula

iTrader: (9)

yeah the slap noise is very common its not a ls thing either its the 3.4 v6 3.1 and so on... heck you can pick out other makes that do it too. only thing that is annoying is the sewing machine noise Ive driven a bunch of corvettes and just like clock work 2k and you hear it.. same as my car

$750 L98

My 6.0 sounds like that at cold start but more of a light tap, aluminum pistons, iron block, but it goes away after a bit.

My LS1 isn't near that bad, but you can hear it during the first few minutes.

Neither of mine have new style or coated skirts sadly.

$750 L98

Indeed, it's just the new lightweight piston designs. Even the GFs Cobalt does it on cold mornings.

The sewing machine doesn't bother me, it sounds more rhythmic to me, and well, I guess normal, since my TPI injectors made the same noise lol

five7kid

iTrader: (14)

When you had the camera down by the tire, that's what mine sounds like.

I borrowed my wife's camera this morning, had it recording when I started it up, and of course it wasn't making the same noise it did yesterday evening. When I got to work, I recorded again, and it was more of the sewing machine sound.

We'll see what it's like when I go out tonight. Should be able to post video this evening.

five7kid

iTrader: (14)

The cold video came out well.




I didn't realize the wind was making so much noise, so the engine sounds generally noisier than it does in person. Happy sewing machine mostly, but faintly you can still make out the slightly louder knock.

cam-

My LS1 never had piston slap that bad but my truck was worse. Mind you it would go away within a few minutes of running and it was really only audible from the drivers seat with the windows up when it was cold outside. I barely noticed it in the summer. As for how the L1 sounds when warmed up? Yours is LOT quieter than mine was LOL. My cam was notorious for valvetrain noise though and I ran a very loose 0.50 pre load with patriot gold springs. It ticked so loud you always heard it

$750 L98

Mine sounds exactly like that when it's started cold and revved, I never rev it when cold if I can avoid it. I usually sit about 3-5 minutes and let it warm up before driving off.

88 350 tpi formula

iTrader: (9)

what size cam do you have in there? the lsx are known to make more noise with the more cam you have.. its not so much lift as the agressive lobes. usually you dont hear the sewing machine sound until 2k then around 3k it goes away or at least the noise get over run by exhaust

in the first vid it sounds a bit loud to me.. the piston slap sounds like a diesel truck but on yours idk if its the camera or what is making it so loud and harsh (has me still wondering) second one sounds normal..

five7kid

iTrader: (14)

I take it very easy until it gets warmed up.

You can get a ticket here doing that...

I'll let it idle while I scrape off the frost, take the garbage cans back from the curb, whatever I can come up with as an excuse to keep from driving away.

five7kid

iTrader: (14)

Stock 2000 Camaro.

It actually sounded louder the evening before. I didn't think the camera picked up the noise very well, actually. I have a 6.5 turbo diesel truck, it doesn't sound like that at all!

This morning when I started it up, it was knocking pretty loud (26 degrees overnight). It didn't quiet down much in the 2.5 miles I drove it. It sat for about an hour and a half, when I started it up again, it was pretty quiet.

I'll probably start pulling the engine this weekend, hope to have it back together, without leaks, by next weekend. Need to get some antifreeze in the other Camaro first so I can take it out of the garage to make room for this one...

one92rs

iTrader: (5)

thats really hard to tell. piston slap will go away. yours last too long. sewing machine sound usually comes from installing a bigger cam causing the rockers to wear a little on top of the valves. i would be suspecting a valvetrain problem. that first vid was loud. i had one similar to that when it had a bad lifter after a cam swap. not a good idea when there is over 120000 on an engine and the want 588 lift. i have also heard a bad valvespring make a noise and last a while. a stcok internal engine should not make the sewing machine noise. from all the ls1's i have swapped cam, heads, and other goodies on they get the sewing maching sound if it is a bigger aftermarket cam. mainly over .550 lift as stock rockers were only designed for no more than .550 lift. that causes a scrubbing the the valve tip.

1quickirocz

My 2000 SS had it real bad. louder than most when it was cold and would never completely go away.....ever. even after hours of driving. bought the car with 29k miles and sold it with almost 80k miles.No probs at all. i guess my point is that its hard to compare to everybody elses car because they are ALL different with how severe it is. You guys know what a rod knock or any other engine noise sounds like in the old SBC stuff...... the LS stuff is no different. A rod knock sounds like a rod knock. a wiped cam sounds like any other wiped cam and so on. I think sometimes the fact that a LSx is typically a louder engine than the older stuff that people get overly concerned with some noise. Since your going to have your engine out anyways it probobly wont hurt to pull the pan and take a look. I dont think I would disassemble the engine though for that noise. Its just a matter of becoming comfortable with the noise and not worrying. Anyways good luck with the disassemble and i hope you dont find anything wrong so you can get it back on the road and enjoy it!!

88 350 tpi formula

iTrader: (9)

they do it stock... like i said its the rate not lift

1quickirocz

Yes Sir I completely agree about the valvetrain noise with larger cams. I was refering to the piston slap. Mine was VERY loud. Got quieter with heat but deff still there. ran like a champ though.

one92rs

iTrader: (5)

it is the lift as well as some of the rate. a non roller tip rocker will scrub the top of the valve causing the noise. rate will cause it to be more.

five7kid

iTrader: (14)

I had the LS1/T56 running yesterday to do a flush & antifreeze fill. It doesn't have a full exhaust yet, but I tried to listen carefully. No particular knock when it was cold, but certainly had some sewing machine sounds to it when warm. I'm reasonably certain it is stock internally (also 2000 Camaro). It wouldn't surprise me if the LS1/4L60E cam is not stock (didn't look it over carefully when I had it out when prepping it for install - I'll look more carefully next time).

five7kid

iTrader: (14)

I was up at a local Corvette specialty business today (sponsors a race series at the track). I've known about them for a few years, but had never gone to see their facility. The owner showed me around (general repair and maintenance, upgrades, body shop, dyno, etc.), and some of the projects they're working on. One was a 2001 Camaro that was getting the 414 that the owner had taken out of his '99 Vette - including the Procharger & intercooler, that took the Vette to the low-10's easily at altitude. In the engine room, he pointed to a longblock covered with plastic and said, "That's the engine that came out of the Camaro. Ran fine. $500."

I'm going to pick it up next week. Take it down, check it over, and if it checks out, put the LS6 cam in it, and move the shaved 317's & Melling oil pump on the currently installed engine and go with this other piece. It's had Mobil 1 since new, the guy wants to look BA but never gets on it, etc. Should be a better foundation than what I've got now. Even if it needs something (like bearings), it should be more trustworthy than pistons that have kissed valves.

mw66nova

iTrader: (13)

good news is you can reuse those cometic gaskets

five7kid

iTrader: (14)

Yes, I was counting on that! Asked the shop what they use, he said Cometic. I asked if they reused them, he said not on PA engines, but should be fine on my NA. He also said use ARP head bolts - "Got 'em already."

White'89

iTrader: (8)

Every motor must be different. My neighbors 5.3L half ton has over 250K on it and not even a hint of piston slap. But that thing couldn't spin the rear tires if its life depended on it.

one92rs

iTrader: (5)

every engine is different no matter how much they try to make them the same. there are freak ones that run very well and then the bad ones. that is why doing the same mods as someone else will almost never get the same results.

five7kid

iTrader: (14)

Update:

I pulled (okay, dropped) the engine/trans finally this weekend to put in that other shortblock (updated with ARP rod bolts, Melling oil pump, LS6 cam). The engine coming out also had an oil leak at the rear. And, I'm going to send the torque converter out to be restalled.

Separated the engine & trans, the oil leak was the rear main seal.

Went to pull the converter out of the front pump, and the flex plate mount ring rattled on the lugs. Apparently they either didn't torque those bolts down sufficiently, or didn't use Loctite, or both. I didn't check them when I installed the converter because they were part of the converter, and the bolts were painted over, and didn't figure there was any need for me to check them.

You can be sure they are going to hear about this when the converter goes back to them.

I'm still going to put the other shortblock in, as its pistons never hit any valves, and it's got the ARP rod bolts.

cuisinartvette

Defintely piston slap, lots of early lSx motors have it some worse than others.

Some had lifter noise issues, my 02 5.3 is one of them. No fix although a bulletin filed by GM. Man I tell you when its cold it sounds horrible!!! AFter a minute or so it quiets down sounds scary when you fire it up lol.

125k and runs like a top though. At 30K+- I complained to the dealer and they said drive it....so I did and still am.

Yours sounds like that dieseling type noise associated with piston slap.

mw66nova

iTrader: (13)

^^did you miss the photos he posted? i'd say he had a bit more than "piston slap" going on there...he had "piston-slappa-da-valves"

five7kid

iTrader: (14)

No, I had "converter-rattlin'-on-da-mount-ring"-itis.

It just seemed louder and harder than "piston slap". Turns out what I was hearing was not piston slap.

Had I kept running it, a loose TC could have gotten ugly. Although I don't think the bolts could have backed out entirely (they were hitting the flex plate), being loose would eventually have fatigued them.

I've had loose torque converter bolts before, but they didn't sound quite like this. Of course, they were loose on the flex plate, while these were loose on the ring that bolts to the flex plate.

cuisinartvette

yes I did see the pic just commented on the sound as many stock ones make the same ones.

five7kid

iTrader: (14)

Most (if not all) accounts indicated piston slap goes away as the engine comes up to temp. This one did not, which raised concerns about either piston or bearing damage.

In thinking back to when I first got the engine running, I didn't hear this noise. But, I had open headers for the first track appearance, and a misfire issue after getting the exhaust hooked up. The noise slowly appeared after that.

Converter ring bolts coming loose completely explains all this. They couldn't back out completely because the bolt heads were up against the flexplate after backing out a little. Good thing, too.

I'm asking the converter outfit to replace the ring and bolts when they do the restall, and to inspect the lugs carefully before shipping it back to me. It would really be nice if they just built me a new converter with the stall I now want (I'm willing to pay for the restall, but the loose bolts are a warranty issue in my mind).

88 350 tpi formula

iTrader: (9)

yeah like a few others said majority of the time piston slap goes away when warm or in some cases it becomes a lot less. the valve train noise rarely goes away. as for the converter noise it makes sense why it would change at times. you would think getting hot it would get worse and a good brake torque would had made it worse as well.

I would be surprised if they cover the bolts as this can be considered a install error.

five7kid

iTrader: (14)

The bolts that came loose were part of the converter. The bolts I installed stayed nice and tight.

88 350 tpi formula

iTrader: (9)

interesting to say the least. guess they have some fixing to do.

mw66nova

iTrader: (13)

why is that ring bolted and not welded to the converter shell?

five7kid

iTrader: (14)

Just the way they chose to build it, I guess. It's the same way the Hughes for my TH400 was built. Better than no ring at all.

five7kid

iTrader: (14)

UPS tracking said the box was delivered Friday, but after business hours. And they aren't open Saturday. So, called them this morning, they said they didn't get anything from me. A little deeper investigation determined UPS delivered it to a completely different street, and a residence, at that. So, I called customer service (not a straight-forward task), they said that was the address they had. I said I was looking at the form I filled out, and that wasn't the address I said. They said I needed to initiate a return form so they could go pick it up and deliver it where I wanted it to go. I said, "This wasn't my mistake. YOU need to take care of it."

"Hold, please..."

After she came back on the line, she said UPS Stores are franchisees, so I would need to talk to the store that shipped it. Great!

At least they aren't too far away. Went over there armed for bear. Showed them the shipping order form, said it was delivered somewhere else. The guy behind the counter looked it up, did a "trial entry" as if entering it for the first time, and the computer did an auto-complete with the street it went to. Okay, that explains it, but doesn't solve the problem. He went ahead and initiated the pickup and redelivery. Supposed to be delivered to the correct address tomorrow.

A few hours later, I got a call on my cell phone. Poor old lady thought someone was sending her a bomb. But, she went ahead and opened it up, found my letter inside, and called. I told her UPS would be picking it up, please give it to them when they show up.

Thought I was going to have to order a new converter and go through the claims process. Hopefully it will be straightened out tomorrow. I was also charged residential delivery, the counter guy said he'd refund the difference for commercial delivery.

The fun never ends...

five7kid

iTrader: (14)

They got the converter. Finally got to it last Friday. Said the Loctite didn't get into the threads on the ring bolts, a technician error. Promised it would be done correctly this time.

They already had it cut apart, said it looked like new inside. The restall is going to add about 600 RPMs, and will be biased to top-end efficiency (as opposed to street efficiency). Should be done and shipped tomorrow.

Hopefully this will put an end to my "piston slap" concerns.