New LS1 Owners - Newbie Tech - Slight knocking on idle




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Vicinity
05-04-2008, 10:38 PM
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.


DVS99TRANS
05-05-2008, 07:15 PM
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.

FatZ28
05-05-2008, 09:18 PM
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.


slowponystreetracer
05-05-2008, 09:53 PM
hold the gas to the floor .... it'll go away.

02ws6NBM
05-05-2008, 10:04 PM
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.

FamousWS6
05-05-2008, 10:16 PM
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

BlkBird2000
05-06-2008, 05:48 AM
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.

StuntmanMike
05-06-2008, 05:54 AM
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.

Mikes96z
05-06-2008, 07:10 AM
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" :)

ws6Ron
05-06-2008, 07:26 AM
My 02 Ws6 Does It Too And I Can't Stand That Sound,say Famousws6what Weight Oil Do You Use.

FamousWS6
05-06-2008, 07:15 PM
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

Vicinity
05-06-2008, 07:36 PM
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.

miamifan3413
05-06-2008, 07:36 PM
Definately piston slap......nothing to worry about.

Cape T/A
05-07-2008, 04:30 PM
my 02 with 19,000 miles does it quit loudly untill it reaches 210 degrees, then i quiets down.

bigblock4-speed
05-08-2008, 01:29 AM
injectors will make noice as well at low rpms if they are aftermarket.... you hear it the most from the intake.....

bigblock4-speed
05-08-2008, 01:30 AM
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..

LS1Silverado05
05-12-2008, 12:36 AM
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.

1sick-Z
05-12-2008, 01:16 AM
+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

qwk93ta
05-12-2008, 05:49 AM
Mine has it when it is cold out....just for a few minutes and then goes away.