Generation III Internal Engine 1997-2006 LS1 | LS6
Sponsored by:
Sponsored by:

Hot Engine Knock

Thread Tools
 
Search this Thread
 
Old Feb 17, 2011 | 08:58 AM
  #1  
O2Form's Avatar
Thread Starter
Banned
 
Joined: Oct 2009
Posts: 992
Likes: 1
Default Hot Engine Knock

My 02 formula has a slight knock hot in gear idling. Sounds like bottom end to me and the lower the rpms the louder it is. The oil is spotless clean and the oil pressure is 45 hot idle 65 cold idle. If I slightly raise the rpms it just blends into the rest of the engine noise. When I 1st bought the car it had a knocking noise that came and went, very bad at times but i'm sure that was a stuck lifter from sitting for 5 years. The knocking i hear now sounds lower but in the same area of no2 cylinder.

I tried running it WOT and getting it hotter it seemed to be a little less noticable but its still there. I know its tough to nail LS1 engines noises down but i'm thinking on this one if it was a bearing it woooood get worse hotter and clatter as I blip the throttle, but it doesn't. I also noticed its really loud cold, this just started after I ran a bottle of Techron in the gas.

I'm going to try pulling the injector leads off one at a time to unload each cylinder to see if it changes but even if i find which cylinder it is I still won't know whats really going on.

Any good input woooood be helpful thanks.

Last edited by O2Form; Feb 17, 2011 at 09:12 AM.
Reply
Old Feb 17, 2011 | 09:15 AM
  #2  
pwrtrip75's Avatar
TECH Addict
20 Year Member
Liked
iTrader: (8)
 
Joined: Jan 2004
Posts: 2,386
Likes: 9
From: Janesville, WI
Default

Mine does the same. Cold its not there or very light. Hot its louder. Ive beat mine severely (turbo 6.0L) and its never failed. I am pulling it apart and replacing the engine though. It is kind of baffling what it could be. It sounds like a bearing, but isnt because it would have flew apart by now.
Reply
Old Feb 17, 2011 | 09:18 AM
  #3  
KevinR's Avatar
TECH Fanatic
 
Joined: Jan 2010
Posts: 1,219
Likes: 0
From: Euless Tx
Default

Is it an A4? Maybe a cracked flexplate??
Reply
Old Feb 17, 2011 | 09:35 AM
  #4  
kinglt-1's Avatar
TECH Senior Member
20 Year Member
Liked
Loved
Community Favorite
iTrader: (26)
 
Joined: Jul 2005
Posts: 5,898
Likes: 255
From: Ft. Wayne, IN
Default

id say if the noise does not get louder as rpm's rise and the oil looks fine, drive it! Ls1's are known to be noisy ****'s.
Reply
Old Feb 17, 2011 | 02:18 PM
  #5  
O2Form's Avatar
Thread Starter
Banned
 
Joined: Oct 2009
Posts: 992
Likes: 1
Default

Yes it is a A4 but the noise is coming more towards the frt around number 2 cylinder. Thanks for the replies, at least its not uncommon.
Reply
Old Feb 17, 2011 | 02:25 PM
  #6  
bayer-z28's Avatar
TECH Veteran
20 Year Member
iTrader: (14)
 
Joined: Apr 2005
Posts: 4,085
Likes: 1
From: N. Falmouth MA
Default

Originally Posted by kinglt-1
id say if the noise does not get louder as rpm's rise and the oil looks fine, drive it! Ls1's are known to be noisy ****'s.
If you can hear it over the exhaust.

OP, how many miles on it? Is the knocking coming from the pass side or driver's? You said #2, so that should be the pass side.. An odd place if it were an oiling issue.
Reply
Old Feb 17, 2011 | 03:05 PM
  #7  
O2Form's Avatar
Thread Starter
Banned
 
Joined: Oct 2009
Posts: 992
Likes: 1
Default

78K on it and honestly i wooood have never noticed if i hadn't drove through Mcds.
Reply
Old Feb 17, 2011 | 03:49 PM
  #8  
KevinR's Avatar
TECH Fanatic
 
Joined: Jan 2010
Posts: 1,219
Likes: 0
From: Euless Tx
Default

I would start simple. Pull the valve covers, and check all the rockers and pushrods.
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

 Brett Foote
story-1

Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

 Pouria Savadkouei
story-2

Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

 Verdad Gallardo
story-3

7 Most Reliable High-Performance Engines GM Has Ever Built

 Verdad Gallardo
story-4

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-5

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-6

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-7

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-8

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-9

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo




All times are GMT -5. The time now is 06:39 PM.

story-0
6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

Don't get dad new socks or a grill brush this year.

By Brett Foote | 2026-06-09 14:55:56


VIEW MORE
story-1
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Slideshow: We take a close look at the ONE and Artidiag 800BT2 diagnostic tools from Topdon and the reasons to buy one over the other.

By Pouria Savadkouei | 2026-05-28 11:05:11


VIEW MORE
story-2
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.

By Verdad Gallardo | 2026-05-26 18:23:54


VIEW MORE
story-3
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


VIEW MORE
story-4
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-5
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-6
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-7
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-8
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-9
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE