New LS1 Owners - Newbie Tech Basic Technical Questions & Advice
Sponsored by:
Sponsored by:

Slight knocking on idle

Old 05-04-2008, 10:38 PM
  #1  
TECH Fanatic
Thread Starter
iTrader: (7)
 
Vicinity's Avatar
 
Join Date: Dec 2007
Location: FL
Posts: 1,752
Likes: 0
Received 0 Likes on 0 Posts

Default Slight knocking on idle

This sounds like nothing all to serious, but I hear a light knocking on idle, and I was wondering if it was normal?

I'm running 93, no cheap gas.
Old 05-05-2008, 07:15 PM
  #2  
TECH Fanatic
iTrader: (7)
 
DVS99TRANS's Avatar
 
Join Date: Nov 2005
Location: E City,NC & Newark,DE
Posts: 1,169
Likes: 0
Received 1 Like on 1 Post

Default

I have it on my WS6 and everytime I go to change the oil at 3000 it still comes out with a goldish color to it. I haven't worried about it because of that. It sounds like a sleight knock then seems to get a little better once the motor is warmed up. I've heard the LS6 blocks can possibly do that and it's on the #1 cylinder. Doesn't mean you have an LS6 motor, just the block possibly if it's on your VIN code.
Old 05-05-2008, 09:18 PM
  #3  
TECH Fanatic
iTrader: (1)
 
FatZ28's Avatar
 
Join Date: Dec 2001
Location: Cleburne,Tx
Posts: 1,642
Likes: 0
Received 2 Likes on 1 Post

Default

Later Ls1's have what is called "piston slap". Someone else is going to have to chime in and tell you the specifics about it, but basically sounds like a knock. Wouldn't be worried about it if that is what it is.
Old 05-05-2008, 09:53 PM
  #4  
Teching In
 
slowponystreetracer's Avatar
 
Join Date: Jul 2007
Location: Strawberry AL
Posts: 35
Likes: 0
Received 0 Likes on 0 Posts
Default

hold the gas to the floor .... it'll go away.
Old 05-05-2008, 10:04 PM
  #5  
Staging Lane
 
02ws6NBM's Avatar
 
Join Date: May 2008
Location: atlanta, ga
Posts: 91
Likes: 0
Received 0 Likes on 0 Posts
Default

my o2 ws6 does the same thing. it is piston slap. some people liken the sound to a diesel engine. i was worried about it because my car has 24k miles on it. a family friend is a shop manager at a gm dealership and he said that he has torn down hundreds of LS engines with the piston slap problem and none of them had any unusual wear on the piston or cylinder wall. like i said, he's a family friend ( grew up with my father) and wouldn't lie to me. so, hope this eases your mind about the noise. From what i've read/heard, just let the motor warm up to operating temp. before you start to burn rubber, and you'll be fine. as a side note, the truck LS engine were really bad with the piston slap. i've heard some trucks that sound just like a duramax diesel, that had LS engines in them.
Old 05-05-2008, 10:16 PM
  #6  
Teching In
 
FamousWS6's Avatar
 
Join Date: Apr 2008
Posts: 47
Likes: 0
Received 0 Likes on 0 Posts
Default

yeah man, my 2002 ws6 has a slight piston slap when i first start it up, it goes away real fast, when it starts warming up. i have been told that using thicker oil will quiet it up real nice, but i have yet to try it. but like o2ws6nbm says, its nothing unusual, and is very common on our cars.

hope this helps


Dave
Old 05-06-2008, 05:48 AM
  #7  
TECH Addict
iTrader: (10)
 
BlkBird2000's Avatar
 
Join Date: Jul 2006
Location: Wood River, IL
Posts: 2,788
Likes: 0
Received 0 Likes on 0 Posts

Default

I kinda freaked out heard it for the first time(few weeks ago). The car still performs good and everything. If you open the car door and step out and just stand there you can hear it real good. tap, tap, tap, tap. It's annoying! I hope nothing is wrong with mine. Mine, I would consider and little louder and more noticeable than a "slight" tapping/knocking noise. But then again I haven't heard yours.
Old 05-06-2008, 05:54 AM
  #8  
TECH Fanatic
iTrader: (2)
 
StuntmanMike's Avatar
 
Join Date: Nov 2007
Location: Newport, RI
Posts: 1,406
Likes: 0
Received 0 Likes on 0 Posts

Default

Yeah, I've noticed that mine does it too. It drives me crazy, but after reading about it so much, I guess it's normal.
Old 05-06-2008, 07:10 AM
  #9  
Launching!
iTrader: (39)
 
Mikes96z's Avatar
 
Join Date: Jun 2007
Location: Columbus, GA
Posts: 225
Likes: 0
Received 0 Likes on 0 Posts
Default

My SS does it so does my 5.3 Z71, I also had it with my 2500hd. Hmmm I'm starting to see a pattern. At least my I-6 Trailblazer is a little more "refined"
Old 05-06-2008, 07:26 AM
  #10  
Teching In
 
ws6Ron's Avatar
 
Join Date: Sep 2007
Location: Houston,tx
Posts: 7
Likes: 0
Received 0 Likes on 0 Posts
Default

My 02 Ws6 Does It Too And I Can't Stand That Sound,say Famousws6what Weight Oil Do You Use.
Old 05-06-2008, 07:15 PM
  #11  
Teching In
 
FamousWS6's Avatar
 
Join Date: Apr 2008
Posts: 47
Likes: 0
Received 0 Likes on 0 Posts
Default

sorry man, like i said in my post, i have yet to try a thicker oil. I heard using amsoil is the best in our cars, but i could be wrong?
Anyone?


Dave
Old 05-06-2008, 07:36 PM
  #12  
TECH Fanatic
Thread Starter
iTrader: (7)
 
Vicinity's Avatar
 
Join Date: Dec 2007
Location: FL
Posts: 1,752
Likes: 0
Received 0 Likes on 0 Posts

Default

Originally Posted by BlkBird2000
I kinda freaked out heard it for the first time(few weeks ago). The car still performs good and everything. If you open the car door and step out and just stand there you can hear it real good. tap, tap, tap, tap. It's annoying! I hope nothing is wrong with mine. Mine, I would consider and little louder and more noticeable than a "slight" tapping/knocking noise. But then again I haven't heard yours.
That's what happens with mine but when you rev up and let off it's more noticeable as you describe.

Well at least I feel better knowing it won't throw a rod or some crazy sh*t like that.
Old 05-06-2008, 07:36 PM
  #13  
TECH Resident
iTrader: (1)
 
miamifan3413's Avatar
 
Join Date: Oct 2005
Location: LaGrange, KY
Posts: 872
Likes: 0
Received 0 Likes on 0 Posts
Default

Definately piston slap......nothing to worry about.
Old 05-07-2008, 04:30 PM
  #14  
10 Second Club
 
Cape T/A's Avatar
 
Join Date: Mar 2008
Location: Cape Girardeau, Missouri
Posts: 1,034
Likes: 0
Received 1 Like on 1 Post
Default

my 02 with 19,000 miles does it quit loudly untill it reaches 210 degrees, then i quiets down.
Old 05-08-2008, 01:29 AM
  #15  
11 Second Club
 
bigblock4-speed's Avatar
 
Join Date: Oct 2007
Location: Columbus, OH
Posts: 429
Likes: 0
Received 1 Like on 1 Post

Default

injectors will make noice as well at low rpms if they are aftermarket.... you hear it the most from the intake.....
Old 05-08-2008, 01:30 AM
  #16  
11 Second Club
 
bigblock4-speed's Avatar
 
Join Date: Oct 2007
Location: Columbus, OH
Posts: 429
Likes: 0
Received 1 Like on 1 Post

Default

that- and i dont really know of any ls1-ls2s having piston slap.. mostly your 99-02ish 1500 trucks with the 5.3 liter do the piston slap on a start up..
Old 05-12-2008, 12:36 AM
  #17  
TECH Addict
iTrader: (41)
 
LS1Silverado05's Avatar
 
Join Date: Jun 2005
Location: Jefferson City, MO
Posts: 2,329
Likes: 0
Received 0 Likes on 0 Posts

Default

Originally Posted by bigblock4-speed
that- and i dont really know of any ls1-ls2s having piston slap.. mostly your 99-02ish 1500 trucks with the 5.3 liter do the piston slap on a start up..
Well, they do. A great many of them do.
Old 05-12-2008, 01:16 AM
  #18  
TECH Apprentice
iTrader: (3)
 
1sick-Z's Avatar
 
Join Date: Feb 2007
Location: In front of Mustangs
Posts: 350
Likes: 0
Received 0 Likes on 0 Posts
Default

+1 on the piston slap but i also could be rocker arms i have heard of needle pins falling out of rockers making them vibrate ever so slightly making a faint ticking noise nothing to worry about but then again neither is the piston slap
Old 05-12-2008, 05:49 AM
  #19  
TECH Addict
iTrader: (13)
 
qwk93ta's Avatar
 
Join Date: Jun 2004
Location: Fairfield, Ohio
Posts: 2,240
Likes: 0
Received 1 Like on 1 Post

Default

Mine has it when it is cold out....just for a few minutes and then goes away.


Thread Tools
Search this Thread
Quick Reply: Slight knocking on idle



All times are GMT -5. The time now is 12:34 AM.