LT1-LT4 Modifications 1993-97 Gen II Small Block V8

Bad vibration

Old Jun 22, 2006 | 08:12 PM
  #1  
Funkybird's Avatar
Thread Starter
TECH Apprentice
iTrader: (4)
 
Joined: Jul 2005
Posts: 386
Likes: 0
From: Utah
Default Bad vibration

I have had this bad vibration ever since i put my new engine in. It is a 355 built by ls1speed and the only things I installed on it was the intake manifold, oil pump and pan, then I installed the engine. The whole car shakes really bad all of the time! Could it be bad motor mounts? Or could it be that something was assembled wrong in the engine? I don't know what to do, Any suggestions?
Reply
Old Jun 22, 2006 | 08:14 PM
  #2  
97BlackLT1TA's Avatar
Launching!
iTrader: (4)
 
Joined: Feb 2006
Posts: 225
Likes: 0
From: South Central Wisconsin
Default

is it cammed?
Reply
Old Jun 22, 2006 | 08:17 PM
  #3  
396D1SS's Avatar
TECH Resident
iTrader: (21)
 
Joined: Feb 2005
Posts: 834
Likes: 0
From: lakeland, fl
Default

driveshaft? unbalaned flywheel?
Reply
Old Jun 22, 2006 | 08:28 PM
  #4  
slowmofo's Avatar
11 Second Club
20 Year Member
iTrader: (6)
 
Joined: Oct 2004
Posts: 1,906
Likes: 1
From: Melbourne, Florida
Default

A4? Did they internaly balance it? then put the stock flex plate on?
Reply
Old Jun 22, 2006 | 08:31 PM
  #5  
infinitebird's Avatar
TECH Veteran
20 Year Member
Liked
iTrader: (11)
 
Joined: Jul 2004
Posts: 4,280
Likes: 51
From: Denver, CO
Default

flexplate or motor mounts most likely
Reply
Old Jun 23, 2006 | 03:49 PM
  #6  
Funkybird's Avatar
Thread Starter
TECH Apprentice
iTrader: (4)
 
Joined: Jul 2005
Posts: 386
Likes: 0
From: Utah
Default

Yes its cammed and it's an A4. It's not the driveshaft cuz it shakes just sitting there. The engine is internally ballanced. I forgot to mention that I also installed the stock flexplate when I got the engine, Should I have had it balanced??? Nobody told me to do anything like that. Thanks for your help guys!
Reply
Old Jun 23, 2006 | 09:00 PM
  #7  
slowmofo's Avatar
11 Second Club
20 Year Member
iTrader: (6)
 
Joined: Oct 2004
Posts: 1,906
Likes: 1
From: Melbourne, Florida
Default

Originally Posted by Funkybird
Yes its cammed and it's an A4. It's not the driveshaft cuz it shakes just sitting there. The engine is internally ballanced. I forgot to mention that I also installed the stock flexplate when I got the engine, Should I have had it balanced??? Nobody told me to do anything like that. Thanks for your help guys!
thats your problem, take the weight off the flex plate or get a unbalanced flex plate.
Reply
Old Jun 24, 2006 | 06:43 PM
  #8  
Funkybird's Avatar
Thread Starter
TECH Apprentice
iTrader: (4)
 
Joined: Jul 2005
Posts: 386
Likes: 0
From: Utah
Default

So that would do it huh? Is that hard to take the weight off? Do you think anything would be harmed from this vibration?
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

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

 Verdad Gallardo
story-1

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-2

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-3

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-4

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
story-5

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

 Verdad Gallardo
story-6

10 Camaros You Should Never Buy

 
story-7

10 LS Engine Myths That Refuse to Die

 Verdad Gallardo
story-8

Five Reasons the Camaro Was the Most Pivotal Player in the Pony Car Wars 2.0

 Brett Foote
story-9

10 Reasons the LS7 Is GM's Most Extreme Naturally Aspirated V8 Engine Ever

 Verdad Gallardo
Old Jun 24, 2006 | 07:55 PM
  #9  
zlover129's Avatar
TECH Fanatic
iTrader: (10)
 
Joined: May 2005
Posts: 1,197
Likes: 0
From: Charlotte, NC
Default

that, and also did they do poly motor mounts? those tend to make the car vibrate
Reply
Old Jun 25, 2006 | 11:47 AM
  #10  
Funkybird's Avatar
Thread Starter
TECH Apprentice
iTrader: (4)
 
Joined: Jul 2005
Posts: 386
Likes: 0
From: Utah
Default

Originally Posted by zlover129
that, and also did they do poly motor mounts? those tend to make the car vibrate
No, I still have the stock ones on.
Reply
Old Jun 25, 2006 | 01:14 PM
  #11  
slowmofo's Avatar
11 Second Club
20 Year Member
iTrader: (6)
 
Joined: Oct 2004
Posts: 1,906
Likes: 1
From: Melbourne, Florida
Default

Originally Posted by Funkybird
So that would do it huh? Is that hard to take the weight off? Do you think anything would be harmed from this vibration?
There was a thread on her not too long ago were the same thing happened to some one else, and he did do damage too his I believe. Im not sure it there hard to get off or not. You might want to look into buying a unbalance flexplate.
Reply
Old Jun 25, 2006 | 07:45 PM
  #12  
Funkybird's Avatar
Thread Starter
TECH Apprentice
iTrader: (4)
 
Joined: Jul 2005
Posts: 386
Likes: 0
From: Utah
Default

K, thanks! I'll check into it.
Reply
Old Jun 25, 2006 | 08:30 PM
  #13  
DeltaT's Avatar
TECH Addict
iTrader: (5)
 
Joined: Jun 2005
Posts: 2,404
Likes: 1
Default

Summit has SFI-rated flexplates for internally balanced motors for a very good price.

Does the LT1/LT4 have a specially weighted harmonic balancer or front pulley as well?

Jim
Reply


Thread Tools
Search this Thread

All times are GMT -5. The time now is 08:24 AM.

story-0
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-1
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-2
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-3
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
story-4
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-5
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-6
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-7
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE
story-8
Five Reasons the Camaro Was the Most Pivotal Player in the Pony Car Wars 2.0

The world was a better place when it was still around.

By Brett Foote | 2026-01-23 09:20:37


VIEW MORE
story-9
10 Reasons the LS7 Is GM's Most Extreme Naturally Aspirated V8 Engine Ever

Slideshow: The 7.0-liter LS7 was designed for absolute cutting-edge performance.

By Verdad Gallardo | 2026-01-07 18:36:00


VIEW MORE