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What's that noise,,, FOUND IT :-/

4xcrazy said:
Due to shortage of funds, and the need to get it running by hopefully next weekend, we just decided to put the stocker unit in it.

Once I get everything in order in the next year here, I'm thinkin if just buying another complete engine and build it from top to bottom.

I was told by the guy at the machine shop, that the 220 cam would not need retuning, It's the same cam he is running in his truck and works fine.
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It will run without having the computer tuned but it won't run right, most cams you put in a ls motor will need the computer tuned to get the most out of it.
 
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ive heard of this happening from Techs at the local GM dealers.

GM claims its from people not changing their oil on time, and going off the light when they use cheap oil.

You stated you changed your oil when you should...and used good oil.

bust hard to say.

Also seen teh o-ring fail on the oil pump, and maybe causing less lubrication to certain parts of the engine
 
Full synthetic Mobile 1 with Mobile 1 filter most of the time, ran a K&N filter once.

The onboard dash light oil change reminder is set at 3000 miles, so I dunno, i pushed it to 4500 running full synthetic, oil never really came out looking horrible.
 
I bet that happened in the first few minutes the engine ran from new....and never got much worse thanks to the synthetic oil....at least roller cams dont have lobes dissapear so rapidly as the old flat tappet cams did,and are now doing more than ever lately, since they started changing oil formulas and taken the zinc out.....................................................................................................I know of 3 name brand cams ( Crane,Sealed Power,and Edelbrock) that were recently installed by a guy who knows his trade well,that failed in less than 2500 miles,despite the proper break in and type of oil being used,and the oil changed after the first day of use...like they forgot to harden some lobes!...the cam company says he didn't break them in right,or used the wrong oil with insufficient zinc additive,etc...he had to "eat" all 3 and replace them out of his pocket...wanted to keep his customers ,and keep them "happy"..all 3 went in small block chevys ,of 1960 and 70's vintage..
 
That seems to be the trend of these companies, blame it on the consumer, they never do anything right.

This engine is also very rarely "raced" meaning excessive high rpm's, can't afford the gas for one, also didn't want to risk this type of failure & downtime, not to mention this added expense now.

I dunno.
 
I've always thought it was generally frowned upon to go scrubbing on the tops of the pistons to remove carbon, there's not a ton of it on them, but enough that I think I'd like to remove it.

What would any of you recommend for this procedure, pretty sure the wire wheel is not the item of choice....
 
Ive had very good luck with spray gasket remover for removing carbon.
Let sit and soak for an hour or so, then wipe off.

Dunno what's in that stuff but it sure knocks carbon down
 
4xcrazy said:
That seems to be the trend of these companies, blame it on the consumer, they never do anything right.
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05 silverado.

A friend of mine had a very bad case of piston slap, and some weird engine noise. He took it in to the local dealer and they wouldn't do any thing.
Then noise got worse. so he brought it back.

Eventually....they said ok, we will tear into the engine, and then we will see whats causing the noise, then determine if is covered under warranty. He hesitantly agreed, but didn't have much options either.

They found the same as yours. Bad cam and lifters.
Then they were not going to cover under warranty, due to driver neglect and improper oil changes. (they claimed)

Then, Josh, my friend, said......um, Ok dip****s, get your story straight.
You (dealership) are the only ones who have ever changed my oil and have record of it every 3000-3500 miles, before the "change oil" light even comes on.

So, in the end they replaced the cam and lifters and oil pump under warranty.

Engine still has piston slap tho, but so do many other LS engines
 
This is an all new engine for me at the moment, learning as I go, these were the stock heads that were on it, they just cleaned them up and replaced anything that needed it.
 
I'm sure they probably checked them for cracks then. But, from what I have seen, the 706 heads were produced by two companys. Castech and some one else. The Castech heads have a tendency to crack around one of Tue bolt holes and it let's water seep up under the bolt head.
 
Yeah, they did the full on rebuild & checked everything on them, I will look for that little symbol when I get home.

Kind of doing this on as strict of budget as I can, as I told a family member, this needs to last just long enough until I get a 6.0 built for it.. :D
 
Hopefully after you get it all together, you will never have any more trouble. And we may never know exactly what happened.

But, going back and listening to the sound, and looking at the damage again, I still say that the lifter looks like impact damage.
Unless it just started spalling under load.

It really sounds to me like there was something binding slightly and not letting the lifter follow the cam fast enough.

That would explain the pinging/knocking sound you heard. If the lifter was floating off the cam as it dropped down and getting slammed by it when the lobe came back up.

After the roller got chipped, it would do the scarring you see on the cam. Probably stopping from time to time on a damaged spot and just sliding along.

I can't think of much that would cause that that would not get fixed in a rebuild. Broken valve spring would have been obvious. But a slightly bent valve stem, or some varnish buildup on a valve guide that let it bind slightly when it warmed up might not.
Actually the bent valve stem would have shown up when it was pulled due to the wear pattern on the stem.

Whatever it was, if it was letting the lifter not return fast enough, it had to be subtle, because otherwise you would have heard a skip or seen a burnt valve.

I don't remember, was it on an intake or exhaust valve?
 
Fordum said:
Hopefully after you get it all together, you will never have any more trouble. And we may never know exactly what happened.

But, going back and listening to the sound, and looking at the damage again, I still say that the lifter looks like impact damage.
Unless it just started spalling under load.

It really sounds to me like there was something binding slightly and not letting the lifter follow the cam fast enough.

That would explain the pinging/knocking sound you heard. If the lifter was floating off the cam as it dropped down and getting slammed by it when the lobe came back up.

After the roller got chipped, it would do the scarring you see on the cam. Probably stopping from time to time on a damaged spot and just sliding along.

I can't think of much that would cause that that would not get fixed in a rebuild. Broken valve spring would have been obvious. But a slightly bent valve stem, or some varnish buildup on a valve guide that let it bind slightly when it warmed up might not.
Actually the bent valve stem would have shown up when it was pulled due to the wear pattern on the stem.

Whatever it was, if it was letting the lifter not return fast enough, it had to be subtle, because otherwise you would have heard a skip or seen a burnt valve.

I don't remember, was it on an intake or exhaust valve?
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Just went and looked, it was an intake valve...#1 cylinder

I think you may be on to someting with this idea, I will admit that there were a few times, while on the throttle heavily, not anything that should have caused any issue, but nonetheless, I could hear either pinging or what sounded like valve rattle from time to time.

I am wondering if the valves weren't bouncing at higher rpm's, maybe need a tighter spring or something, I dunno. I was doing some research and saw some people commenting about lifter chatter or something, like the roller doesn't get to roll over the cam smooth, it sort of bounces. It's usually visable apparently during tear down for any other reason.

I inspected all other roller tips on the lifters, none were horribly worn, but most had some sort of small line on them. Nothing you could really feel, but just barely visable, one was very visable, I believe that was the one opposite intake #2 cylinder.

Either way, they are all getting replaced, and I believe I'm going to pull a rod cap or two for a quick inspection tomorrow during other clean up stuff and whatever I can do to prepare for reassembly.
 
AH WELL FRACK !!

Engine is coming out for a full rebuild...

As I was cleaning the block deck, preparing for reassembly, I happened to see down in an opening alittle better, cam bearings are trashed.

First bearing in front didn't look too bad, but second one was REALLY worn in.

This thing has either been seriously neglected by the previous owner for it's first 50k miles, or the oil changes places Jenn used to take it to were not actually changing the oil out like they were supposed to be doing.

I dunno, with the caked on layer of burnt looking oil on everything internal, something was definitely not right with this engine.

Ah well, gonna be all new now, I'll know exactly how it's going to be driven and treated as far asd fluids and changes.

Just alittle rough right now with the finances to be spending money on this thing, but we will prevail. :waytogo:
 
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