LS6 Engine Noise
Thread Starter
Pro
Joined: Jul 2005
Posts: 573
Likes: 6
From: Wichita KS
LS6 Engine Noise
Just curious if anyone has seen (heard) this before. My engine when cold makes a somewhat hollow knock/rattle sound. It seems to be loudest around the intake manifold, but it's tough to locate exactly. At first I thought it was piston slap, but it's not very rhythmic. It goes away once the motor warms up. Takes several minutes though.
I made a video just for the sound. You can hear it in the background as I pan around. It's particularly noticeable around the 18-20 sec mark.
https://drive.google.com/file/d/0B89...ew?usp=sharing
I made a video just for the sound. You can hear it in the background as I pan around. It's particularly noticeable around the 18-20 sec mark.
https://drive.google.com/file/d/0B89...ew?usp=sharing
Le Mans Master
Joined: Feb 2012
Posts: 6,644
Likes: 478
From: OK
It's a simple thing, but it works... take an old broom handle and while it's making the rattle start placing the handle on different parts/sections of the engine...pressing the other end of the handle against your ear... till you PIN point where the sound is coming from...it's amazing all the different sounds your engine makes... some whrrring, some whooshing... some purring...and the occasional tick or rattle... this may help give you an idea to WHAT is making the sound...
Try it! IT's simple and free
Try it! IT's simple and free
Last edited by 73Corvette; Sep 2, 2015 at 12:36 AM.
Thread Starter
Pro
Joined: Jul 2005
Posts: 573
Likes: 6
From: Wichita KS
And maybe that's what it is (piston slap). I actually have a automotive stethoscope. I tried it first but couldn't hear this particular sound no matter where I put it.
I'll be at Solo Nats next week. I'll troll around and see if I hear the same thing on other cars. Mine started this last fall/winter though.
I'll be at Solo Nats next week. I'll troll around and see if I hear the same thing on other cars. Mine started this last fall/winter though.
Last edited by talon95; Sep 2, 2015 at 07:24 AM.
Burning Brakes
Joined: Jul 2007
Posts: 881
Likes: 2
From: hill billy hell
I have an 03 with 54k on it, and the noise I heard around 19-22 mark on video sounds like mine when I start up for about 6yrs now.
Mine sounds like a old diesel engine knock.
Hope you figure it out if its not piston slap that you are hearing
Mine sounds like a old diesel engine knock.
Hope you figure it out if its not piston slap that you are hearing
Thread Starter
Pro
Joined: Jul 2005
Posts: 573
Likes: 6
From: Wichita KS
That's good to know. I don't really care as long as it's not terminal. My car is an '03 with 52k. Although it also has 10 years of autocrossing on it.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
DRIVE IT LIKE YOU STOLE IT!~ 
If it were me, the only thing I would really check is to make sure that your valve rocker trunions are not starting to puke out the small roller bearings.
The noise is very slight and IMHO, very normal for a 50K+ engine.
BC
If it were me, the only thing I would really check is to make sure that your valve rocker trunions are not starting to puke out the small roller bearings.
The noise is very slight and IMHO, very normal for a 50K+ engine.
BC
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Le Mans Master
Joined: Feb 2012
Posts: 6,644
Likes: 478
From: OK
I finally actually listened to your video, but, I'm so hard of hearing I may not even be hearing what the rest of you are... pretty good quality sound for the innerweb.... JMHO it sounds like belt chirp/rattle...
If it's metal/mechanical, injector, etc... you should be able to PINPOINT it with the scope...
See if it does without the belt on... plus there would be less noise to try and scope again... cost nothing to do.
If it's metal/mechanical, injector, etc... you should be able to PINPOINT it with the scope...
See if it does without the belt on... plus there would be less noise to try and scope again... cost nothing to do.
Thread Starter
Pro
Joined: Jul 2005
Posts: 573
Likes: 6
From: Wichita KS
I finally actually listened to your video, but, I'm so hard of hearing I may not even be hearing what the rest of you are... pretty good quality sound for the innerweb.... JMHO it sounds like belt chirp/rattle...
If it's metal/mechanical, injector, etc... you should be able to PINPOINT it with the scope...
If it's metal/mechanical, injector, etc... you should be able to PINPOINT it with the scope...
Team Owner
Joined: Oct 1999
Posts: 31,976
Likes: 486
From: Guinness Its whats for B'fast JAWGA
CI 3-4-5-9 Veteran
I didn't hear anything all that unusual. I would pull the plugs and take a look for anything strange. You can also send the oil off to someone like blackstone labs.
Racer
Joined: Jan 2015
Posts: 499
Likes: 63
From: Arkansas
After listening to your motor,, I'm going to go out today and put the stethoscope on the ZO6 motor, see what I can discover.
I've been thinking it's a rocker on my sons ZO6, which would be odd for a LS6 with such low miles and driver reasonable easy.
My recommendation is to get a stethoscope and test with the drive belts removed. I'm going to try to get to this today, I'll let you know what I find.
BTW, my concern is that it very well could be a rocker on the LS6 motor, so my concern is that I wound not want to have a rocker fail while driving. Better for me to know positively that this noise is not a rocker, Hoping it's belt noise
good luck,,,
Michael
