LS2 Engine Knock
Instructor
Joined: Oct 2009
Posts: 216
Likes: 0
From: Edmonton Alberta
if the dealer is saying the engine must come out it is serious. If it is a bearing you should be able to see it in the pan or the filter. Like others have noted, the LS series are known for piston slap. I have an 02 Firehawk with an LS1 that has done it since new. Part of it is the aluminum block I believe that allows the sounds to translate or ne more noticable
Cruising
Joined: Jul 2009
Posts: 14
Likes: 0
im going through the same thing. It really only under a light accel, not in park. I mgoing to try to go from 5w to 10w oil, but the dealer must be def everytime i go back. Everyone else can hear it and they cant, go figure.
Safety Car
Joined: Dec 2006
Posts: 4,642
Likes: 9
From: Dalllas/Ft Worth Area TX
Lots of things to take into consideration!
When it comes to engine knock or slap there are alot of things to take into consideration:
1. Mileage on engine
2. Viscosty of oil
3. Temperature of engine
4. Tolorance of each individual part
5. RPM of engine
6. Load on engine
7. Wear of each individual part
8. Temperature expansion of each individual part
9. Type of material used in part
10. Play in different parts
11. Etc.
Their are so many variables in play here that there is not an easy answer to solve this problem unless something is WAY, WAY OFF. For example: play in wrist pins, even the end play.
In trying to solve the actual noise can be difficult, a stethescope or even a stick stethescope can help locate the problem area.
Myself, I don't like the noise, but the cure is as difficult as finding disease many times. Too many variables AND we didn't buy a "racing engine", just an assembly line built engine. As long as we can "wrap" the engine up and it doesn't explode (blow apart), we just usually have to accept our "special" (imperfect) engine, unfortunately. Just think, race car engines ALSO blow, so this is not unique. Sorry for the bad news.
1. Mileage on engine
2. Viscosty of oil
3. Temperature of engine
4. Tolorance of each individual part
5. RPM of engine
6. Load on engine
7. Wear of each individual part
8. Temperature expansion of each individual part
9. Type of material used in part
10. Play in different parts
11. Etc.
Their are so many variables in play here that there is not an easy answer to solve this problem unless something is WAY, WAY OFF. For example: play in wrist pins, even the end play.
In trying to solve the actual noise can be difficult, a stethescope or even a stick stethescope can help locate the problem area.
Myself, I don't like the noise, but the cure is as difficult as finding disease many times. Too many variables AND we didn't buy a "racing engine", just an assembly line built engine. As long as we can "wrap" the engine up and it doesn't explode (blow apart), we just usually have to accept our "special" (imperfect) engine, unfortunately. Just think, race car engines ALSO blow, so this is not unique. Sorry for the bad news.
1st Gear
Joined: Sep 2022
Posts: 1
Likes: 1
Piston Slap
I use Liqui-Moly Cera Tec oil additive. I first heard of this when I was researching engine knocking in 5.0 Coyote motors. I have a F150 that has the 5.0 and has the annoying piston slap knock. I used the Liqui-Moly Cera Tec and it quieted down the knock significantly. I use 1 bottle at every oil change. My C6 had a very slight knocking noise so I threw in a bottle at my next oil change and the knock is gone. Give it a try.
Race Director
Joined: Sep 2003
Posts: 16,838
Likes: 341
From: Database Error Indiana
I use Liqui-Moly Cera Tec oil additive. I first heard of this when I was researching engine knocking in 5.0 Coyote motors. I have a F150 that has the 5.0 and has the annoying piston slap knock. I used the Liqui-Moly Cera Tec and it quieted down the knock significantly. I use 1 bottle at every oil change. My C6 had a very slight knocking noise so I threw in a bottle at my next oil change and the knock is gone. Give it a try.
2010 thread is 12 years old.
