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Old 09-24-2011, 08:20 PM   #1
achilds
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Default LS2/LS3 failures

I have been reading over on the Z06 forum that there is something wrong with the LS7 motor. There have been 25 reports of failure on stock motors, split about half and half for exhaust valve failure and what looks like bearing failure due to lack of lubrication. One of the arguements put forward is that this is a significant number of failures for the valves and that there isn't a correpsonding number of LS2/LS3 failures therefore the LS7 is flawed. My question to the LS2/LS3 community is how many stock engine failures is this community aware of? Any info would be appreciated.
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Old 09-24-2011, 09:09 PM   #2
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I have a 06 z06 I'm on motor #2 dropping valves...I don't think its an ls2 or ls3 issue
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Old 09-24-2011, 09:40 PM   #3
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Originally Posted by z0sicktanner View Post
I have a 06 z06 I'm on motor #2 dropping valves...I don't think its an ls2 or ls3 issue
I am just curious as to the number of LS/2/3's failing. The postion that 13 occurrances of dropped valves on stock motors is reason to panic just doesn't sit well with me. The arguement is made that there are many more LS2/3's out there and that there are no failures so the LS7 must be a bad motor made me want to ask the question. So I asked, let's see what the LS2/3 community has to say, maybe they have a more robust motor, maybe there have been 50 or 60 failures won't know unless we ask I guess.

Sorry to hear about your problems though.
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Old 09-24-2011, 10:57 PM   #4
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I killed an LS3 bolton only at 71K miles. It was really hard to tell the first point of failure, but a serious overrev was caused by the rev limiter being set way too high by a traveling tuner.

There were no broken springs, but there were bent pushrods, and a headless intake and exhaust valve. The residual damage included a broken rod, two disintegrated pistons, a couple of badly beaten heads, and a missing chunk of cylinder wall.

As a guess, I'd say one of the valves lost it's head first.
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Old 09-24-2011, 11:05 PM   #5
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Quote:
Originally Posted by achilds View Post
I have been reading over on the Z06 forum that there is something wrong with the LS7 motor. There have been 25 reports of failure on stock motors, split about half and half for exhaust valve failure and what looks like bearing failure due to lack of lubrication. One of the arguements put forward is that this is a significant number of failures for the valves and that there isn't a correpsonding number of LS2/LS3 failures therefore the LS7 is flawed. My question to the LS2/LS3 community is how many stock engine failures is this community aware of? Any info would be appreciated.
Some references:
http://www.g8board.com/forums/showthread.php?t=21450

http://ls1tech.com/forums/esp_search...v-bar&type=all

http://ls1tech.com/forums/esp_search...v-bar&type=all

http://www.facebook.com/media/set/?s...8&l=c488e47454

And there must be more at other forums for the LS2/3...

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Old 09-25-2011, 12:14 AM   #6
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Originally Posted by achilds View Post
I am just curious as to the number of LS/2/3's failing. The postion that 13 occurrances of dropped valves on stock motors is reason to panic just doesn't sit well with me. .
So there have only been 13 failures, out of how many made?

Remember this...how many owners MANUALLY over rev the car by downshifting or mis shifting, and are not admitting to it. Or how many times do you think that happened on the motors that failed?

You can manually over rev the motor and not have failure at that time, it can crack a valve spring or bend a valve and not "let go" until a later date.....
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Old 09-25-2011, 02:05 AM   #7
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Quote:
Originally Posted by z0sicktanner View Post
I don't think its an ls2 or ls3 issue
It isn't...I don't recall hearing about any (stock, unabused) LS2s/LS3s ever failing.
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Old 09-25-2011, 02:50 AM   #8
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Quote:
Originally Posted by m R g S r View Post
So there have only been 13 failures, out of how many made?

Remember this...how many owners MANUALLY over rev the car by downshifting or mis shifting, and are not admitting to it. Or how many times do you think that happened on the motors that failed?

You can manually over rev the motor and not have failure at that time, it can crack a valve spring or bend a valve and not "let go" until a later date.....
I agree with the operator error thougt. I brought it up on the Z06 forum, but the arguement was that this could be true for LS2/3's as well. There is some merit to that arguement I suppose.

13 stock motors reported on the forum. 27,000 made, but the arguement is not all are on the forum. There is about 2 or 3x that many, but they were modded.
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Old 09-25-2011, 03:01 AM   #9
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That's an interesting point, did these LS2/LS3 (and even LS7) failures happen on bone stock vehicles that were just leisurely driving down the road?
Or were the owners riding them on the rev limiters for a few minutes or worse yet, using their own hand held tuning units/HP Tuners etc to actually raise the rev limiter on their otherwise bone stock valvetrains and taking their cars to 7500rpm?
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Old 09-25-2011, 07:04 AM   #10
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Quote:
Originally Posted by achilds View Post
I have been reading over on the Z06 forum that there is something wrong with the LS7 motor. There have been 25 reports of failure on stock motors, split about half and half for exhaust valve failure and what looks like bearing failure due to lack of lubrication. One of the arguements put forward is that this is a significant number of failures for the valves and that there isn't a correpsonding number of LS2/LS3 failures therefore the LS7 is flawed. My question to the LS2/LS3 community is how many stock engine failures is this community aware of? Any info would be appreciated.
That's roughly .08 percent of all Z06s produced. One would think if the LS7 is flawed it would be slightly higher than a minute fraction of 1 percent?
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Old 09-25-2011, 11:32 AM   #11
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Quote:
Originally Posted by LS1LT1 View Post
That's an interesting point, did these LS2/LS3 (and even LS7) failures happen on bone stock vehicles that were just leisurely driving down the road?
Or were the owners riding them on the rev limiters for a few minutes or worse yet, using their own hand held tuning units/HP Tuners etc to actually raise the rev limiter on their otherwise bone stock valvetrains and taking their cars to 7500rpm?
The claim is bone stock, some say just driving along at a normal speed. Who really knows. Anyway sure would like to get a count of LS2/3's in stock form that have failed.
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Old 09-25-2011, 12:01 PM   #12
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Originally Posted by LS1LT1 View Post
It isn't...I don't recall hearing about any (stock, unabused) LS2s/LS3s ever failing.
where are you drawing your sample from? Most people on this forum, (and others that we frequent) don't have stock motors and or are cars are driven hard/raced.
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Old 09-25-2011, 12:29 PM   #13
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Hello,

My stock (Vararam only) 2006 LS2 motor blew at 20,000 miles. Headgasket failure led to #1 cylinder hydrolocking and exploding, connecting rod fell down and jammed against #2 cylinder and broke that connecting rod and shoved it throught the block!

1 year out of warranty and GM said sorry we can't help.

Paid full price for new engine and installation at Gandrud Dealership in Green Bay. They did excellent work and car runs great!

Douglas in Green Bay
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Old 09-26-2011, 02:02 PM   #14
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A certain percentage of any motor will fail prematurely; and the percentage will go up the harder you run the motors, even if you don't actually violate the numbers by over revs, etc.

I don't know if the LS7 has a higher percentage of failures than the LS2/LS3, though it kinda seems that way. Only GM knows for sure. But the big question is, how much harder are the owners running those cars?
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Old 09-26-2011, 02:58 PM   #15
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It is also important to keep in mind that not ALL Corvette owners are members of the Forums, so there are a lot more actual failures, than those reported on the Forums that we read about.
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Old 09-26-2011, 03:21 PM   #16
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Quote:
Originally Posted by z0sicktanner View Post
I have a 06 z06 I'm on motor #2 dropping valves...I don't think its an ls2 or ls3 issue
Is it isolated to just a valvespring issue?
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Old 09-26-2011, 03:23 PM   #17
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Originally Posted by LS1LT1 View Post
It isn't...I don't recall hearing about any (stock, unabused) LS2s/LS3s ever failing.
Didn't the LS3s have the timing chain issues.
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Old 09-26-2011, 03:23 PM
 
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