# GM Engines: "Like a Knock"
**URL:** https://forums.speedlife.net/t/gm-engines-like-a-knock/7924
**Category:** NYSpeed Automotive
**Created:** [February 8, 2006, 3:15pm UTC](https://forums.speedlife.net/t/gm-engines-like-a-knock/7924 "2006-02-08T15:15:51Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@Onyx\_Z32](https://forums.speedlife.net/u/Onyx_Z32)
#### Post date: [February 8, 2006, 3:15pm UTC](https://forums.speedlife.net/t/gm-engines-like-a-knock/7924/1 "2006-02-08T15:15:51Z")
Wow… [Click HERE](http://www.pistonslap.com/photos.htm) - Photos and sound clips.
_“The very evidence provided by the manufacturer
(GM) to indicate this condition is not a problem ultimately demonstrates that it is a problem.”
California BBB Arbitrator_
“…a knocking engine could lower the value
of a vehicle by $4,000 to $6,000 at trade-in”
Charlie Vogelheim, executive editor for Kelley Blue Book
Detroit Free Press
“My 2004 8.1L is knocking with less then 2K miles”
post on [pistonslap.com](http://pistonslap.com) forum
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### Author:  [@neurokinetik](https://forums.speedlife.net/u/neurokinetik)
#### Post date: [February 8, 2006, 3:17pm UTC](https://forums.speedlife.net/t/gm-engines-like-a-knock/7924/2 "2006-02-08T15:17:51Z")
It is a known issue with certain year LS1s. It goes away after warmup. Trading your car in? Go for a little drive first. Problem solved.
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### Author:  [@tpgsr](https://forums.speedlife.net/u/tpgsr)
#### Post date: [February 8, 2006, 3:20pm UTC](https://forums.speedlife.net/t/gm-engines-like-a-knock/7924/3 "2006-02-08T15:20:10Z")
WOW, that sucks. Glad i dont have a tahoe, even though I really do like them.
I love how that guy had it vinyl’d, i would park right in front of the dealer as often as possible
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### Author:  [@Adictd2b00st](https://forums.speedlife.net/u/Adictd2b00st)
#### Post date: [February 8, 2006, 3:24pm UTC](https://forums.speedlife.net/t/gm-engines-like-a-knock/7924/4 "2006-02-08T15:24:35Z")
i thought i noticed that when i would pull in gm’s at work…this don’t suprise me then :tdown:
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### Author:  [@Jack](https://forums.speedlife.net/u/Jack)
#### Post date: [February 8, 2006, 4:01pm UTC](https://forums.speedlife.net/t/gm-engines-like-a-knock/7924/5 "2006-02-08T16:01:16Z")
> [@neurokinetik](#):
>
> It is a known issue with certain year LS1s. It goes away after warmup. Trading your car in? Go for a little drive first. Problem solved.
:word:
I don’t quite see what the problem is?
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### Author:  [@1sik\_bmw](https://forums.speedlife.net/u/1sik_bmw)
#### Post date: [February 8, 2006, 5:06pm UTC](https://forums.speedlife.net/t/gm-engines-like-a-knock/7924/6 "2006-02-08T17:06:28Z")
.
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### Author:  [@Firehawk853](https://forums.speedlife.net/u/Firehawk853)
#### Post date: [February 8, 2006, 5:21pm UTC](https://forums.speedlife.net/t/gm-engines-like-a-knock/7924/7 "2006-02-08T17:21:11Z")
Mine went away after i rebuilt 😉
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### Author:  [@nitroinsane](https://forums.speedlife.net/u/nitroinsane)
#### Post date: [February 8, 2006, 5:23pm UTC](https://forums.speedlife.net/t/gm-engines-like-a-knock/7924/8 "2006-02-08T17:23:24Z")
GTPS WERE KNOWN FOR IT TO.
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### Author:  [@Bacon](https://forums.speedlife.net/u/Bacon)
#### Post date: [February 8, 2006, 6:36pm UTC](https://forums.speedlife.net/t/gm-engines-like-a-knock/7924/9 "2006-02-08T18:36:01Z")
:tup: To this guy, probably easily cost GM the price of engine if just one person didn’t buy a GM because of this.
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### Author:  [@2TurboZ](https://forums.speedlife.net/u/2TurboZ)
#### Post date: [February 8, 2006, 6:44pm UTC](https://forums.speedlife.net/t/gm-engines-like-a-knock/7924/10 "2006-02-08T18:44:41Z")
Well, i have blown up every GM engine I have ever driven…so I can say that from personal experience I wouldnt buy one.
But maybe this is God’s joke…since the almighty LS1 was built by the hands of God…maybe he just did it to be funny :lol:
:gotme:
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### Author:  [@Jskrapper](https://forums.speedlife.net/u/Jskrapper)
#### Post date: [February 8, 2006, 6:49pm UTC](https://forums.speedlife.net/t/gm-engines-like-a-knock/7924/11 "2006-02-08T18:49:37Z")
It’s also considered “normal” for the 8.1 to go through a quart of oil every 1000 miles.
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### Author:  [@JaysGreenLX](https://forums.speedlife.net/u/JaysGreenLX)
#### Post date: [February 8, 2006, 6:51pm UTC](https://forums.speedlife.net/t/gm-engines-like-a-knock/7924/12 "2006-02-08T18:51:04Z")
> [@Jskrapper](#):
>
> It’s also considered “normal” for the 8.1 to go through a quart of oil every 1000 miles.
I’ve heard that too. These engines must have some wicked tolerances.
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### Author:  [@BIGHANDS](https://forums.speedlife.net/u/BIGHANDS)
#### Post date: [February 8, 2006, 6:58pm UTC](https://forums.speedlife.net/t/gm-engines-like-a-knock/7924/13 "2006-02-08T18:58:18Z")
yeah gm is fucking evryone i have heard some of those knock pretty bad ive done a few piston replacements on the 3.4 in the venture vans and the new teflon coated pistons cured the noise but that is such a bandaid gm =the poop
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### Author:  [@LZ1](https://forums.speedlife.net/u/LZ1)
#### Post date: [February 8, 2006, 7:03pm UTC](https://forums.speedlife.net/t/gm-engines-like-a-knock/7924/14 "2006-02-08T19:03:28Z")
Yep GM sucks
Gen III V8s like the LS1 and LS6 suck
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### Author:  [@rj-92](https://forums.speedlife.net/u/rj-92)
#### Post date: [February 8, 2006, 7:08pm UTC](https://forums.speedlife.net/t/gm-engines-like-a-knock/7924/15 "2006-02-08T19:08:13Z")
So what exactly is wrong with these motors and what causes the problem?
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### Author:  [@Jskrapper](https://forums.speedlife.net/u/Jskrapper)
#### Post date: [February 8, 2006, 7:11pm UTC](https://forums.speedlife.net/t/gm-engines-like-a-knock/7924/16 "2006-02-08T19:11:16Z")
> [@rj-92](#):
>
> So what exactly is wrong with these motors and what causes the problem?
Little or no skirts on the pistons (less mass) and the ring cluster is closer to the top of the piston (better combustion).
edit: It all means that the tolerances have to be that much tighter, wich is not easy on a mass production engine.
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### Author:  [@neurokinetik](https://forums.speedlife.net/u/neurokinetik)
#### Post date: [February 8, 2006, 7:15pm UTC](https://forums.speedlife.net/t/gm-engines-like-a-knock/7924/17 "2006-02-08T19:15:51Z")
All GM owners should park their vehicles next to Nissans and Mazdas, the lifter tick will drown out the piston slap… 😛
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### Author:  [@MaximaSE98](https://forums.speedlife.net/u/MaximaSE98)
#### Post date: [February 8, 2006, 7:29pm UTC](https://forums.speedlife.net/t/gm-engines-like-a-knock/7924/18 "2006-02-08T19:29:37Z")
> [@neurokinetik](#):
>
> All GM owners should park their vehicles next to Nissans and Mazdas, the lifter tick will drown out the piston slap… 😛
true true…but hey at a 195k my old nissan still runs perfect and blows no smoke and has no piston noise…just the usual tick…
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### Author:  [@Jack](https://forums.speedlife.net/u/Jack)
#### Post date: [February 8, 2006, 7:31pm UTC](https://forums.speedlife.net/t/gm-engines-like-a-knock/7924/19 "2006-02-08T19:31:14Z")
hahaha…
hey your car is ticking…
really? I’ve been driving it for tens of thousands of miles and your the first and only person to ever point that out to me… gee golly mister… thanks!
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### Author:  [@MikeRi24](https://forums.speedlife.net/u/MikeRi24)
#### Post date: [February 8, 2006, 7:34pm UTC](https://forums.speedlife.net/t/gm-engines-like-a-knock/7924/20 "2006-02-08T19:34:55Z")
the ‘old school’ TBI 305s and 350s in the trucks will run forever. ive had a 350 in a 88 truck with 198,000 and it jsut needed a few new gaskets which i decided not to fix and get rid of the truck (bad move) and now i have a 305 in a 88 truck with almost 203,000 on it and its still purring like a kitten. those engins are the shit if u ask me
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