LS1 piston slap or something else?
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LS1 piston slap or something else?
https://m.youtube.com/watch?v=Ehv1iMIAIKk&app=m&persist_app=1#
This is my 98 c5 cold start im trying to figure out what this noise is before I sink 10k in the motor and still have a issue. Only makes the knock/tick during cold start once car is warm noise goes away.
This is my 98 c5 cold start im trying to figure out what this noise is before I sink 10k in the motor and still have a issue. Only makes the knock/tick during cold start once car is warm noise goes away.
Last edited by Vince98; Dec 10, 2014 at 02:49 PM.
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That's typical for the LS1 engines from my experience. I'm not hearing anything unusual.
Here's some help with the link:
http://www.youtube.com/attribution_l...m-upload_owner
You do need to clean that engine though....
Here's some help with the link:
http://www.youtube.com/attribution_l...m-upload_owner
You do need to clean that engine though....
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Ok good deal. I'm about to replace cam, springs, pushrods, lifters, rockers, oil pump, timing set and throw a A&A si trim on it. Just wanted to see what everyone thought before I started putting some boost to it.
Racer
Joined: Dec 2013
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From: Maryland
Back in 2003 I bought a 2000 Trans Am ( with the LS1 ) w only 26K on it and from the start it would make some piston slap on ANY COLD START no matter what the air temp. outside. Admittedly it was a little worse when it was really cold outside. After a minute or 2 it would ALWAYS go away (after it warmed up). It did that the entire time I owned the car, until I sold it 10 years later with 79K. The car still ran like a clock when I sold it. <sigh> IF I was super rich, I probably would've kept it. It was a cherry.....
But anyway.............. just recently got a '99 vette with 62K and it does the same thing.......
It does seem like an "LS1" thing.............no biggie.
But anyway.............. just recently got a '99 vette with 62K and it does the same thing.......
It does seem like an "LS1" thing.............no biggie.
Last edited by JayTee72; Dec 10, 2014 at 06:29 PM.
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LSI Piston Slap
I have had three C-5s; 2 of the three rattled when cold. I have a BB Chev in an older muscle car with forged pistons; it sounds like a peanut thrashing machine when cold. Just like you say when it warms up all is quiet. I say don't give it a second thought. 
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Yup, mine does it too. I brought it to my mechanic, my HONEST mechanic. He asked one question, does it make that noise when it's warmed up. And of course the answer is No. He just smiled and said Don't worry about it. According to him, the engine hasn't expanded to where the operating tolerances are met until it's at full or near full operating temperature. Once its at operating temperature, the correct clearances are in play and the noise is gone. Anyway, his explanation works for me. I know he works on other Vettes so I'm guessing he's seen this before.
Melting Slicks
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Yup, mine does it too. I brought it to my mechanic, my HONEST mechanic. He asked one question, does it make that noise when it's warmed up. And of course the answer is No. He just smiled and said Don't worry about it. According to him, the engine hasn't expanded to where the operating tolerances are met until it's at full or near full operating temperature. Once its at operating temperature, the correct clearances are in play and the noise is gone. Anyway, his explanation works for me. I know he works on other Vettes so I'm guessing he's seen this before.
Sounds normal to me too.But what is that noise exactly? I was under the impression that it was valve train, not pistons.
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On my two '99's, one is quiet and the other makes the noise when first started. It usually is gone by the time I pull out of the driveway. The one that makes noise has about 60k miles and seems to be in very good shape. It runs good and no oil consumption. I think it is so common it is a normal thing.