knocking sound when engine is cold
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Pro
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knocking sound when engine is cold
I think i heard some knocking sound (hard to hear) from the engine when i first started the car in the morning then drive it right a way. if i leave it run a about a min the drive it's ok. Any ideas? Thanks
Race Director
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From: Hockessin Delaware
Re: knocking sound when engine is cold (00c5coupe)
I've heard it's perfectly normal, don't really understand why though. Mine does it also, but only when cold. I think this has been discussed a few times - you can try a search. :seeya
Instructor
Joined: Feb 2002
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From: C5 Land
Re: knocking sound when engine is cold (DsC5)
Perfectly normal? No way!
One or two cylinders are slightly overbored. (Factory error).
We are not so unlucky as the truck guys though, some of the engines in the trucks are really knocking and "dieseling".
The knocking will increase with the mileage..... :mad
But don´t expect GM to do anything about it, they will just say it´s "normal" and offer you an extended no-good warranty.
One or two cylinders are slightly overbored. (Factory error).
We are not so unlucky as the truck guys though, some of the engines in the trucks are really knocking and "dieseling".
The knocking will increase with the mileage..... :mad
But don´t expect GM to do anything about it, they will just say it´s "normal" and offer you an extended no-good warranty.
Race Director
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From: Hockessin Delaware
Re: knocking sound when engine is cold (The Laplander)
I'm not sure whether it's normal or not - notice I said "I've heard it's perfectly normal." Somebody with a greater technical understanding than me will have an explanation. :seeya
[Modified by DsC5, 9:25 PM 4/22/2002]
[Modified by DsC5, 9:25 PM 4/22/2002]
Melting Slicks
Joined: Apr 2002
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From: Addison IL
Re: knocking sound when engine is cold (00c5coupe)
A month ago I bought a used 00 with 12,199 on it. Warranty till 05/03. It knocked 2 different times aftewr sitting overnight in garage..ambient temp about 50 degrees. Hadit going to dealer for minor things I found. Asked writer to check for knock...new pistons ad rings per Chevy. $3400. warranty. Run to dealer ask to have it checked, a buddy of mine works for GM out of Atlanta, I asked him and he replied that there are/were some bad rings and or pistons. Talk nice to he service writer.
He can check with mine, a really great guy at BILL KAY CHEVY, Lisle, IL. 630 968 2900 XT 3334..MARK BOWLING. They did all 8.
[Modified by Stilcrazee, 3:22 AM 4/23/2002]
He can check with mine, a really great guy at BILL KAY CHEVY, Lisle, IL. 630 968 2900 XT 3334..MARK BOWLING. They did all 8.
[Modified by Stilcrazee, 3:22 AM 4/23/2002]
Melting Slicks
Joined: Mar 2001
Posts: 2,667
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From: New Jersey
Re: knocking sound when engine is cold (Stilcrazee)
The knock is caused by piston skirt slap, until the piston expands (heat) and the clearance decreases. Will it hurt anything in the long-run ? : probably not (pistons are softer aluminum, cylinder wall is a hard cast-iron liner), but it certainly doesn't enhance engine longevity or owner satisfaction!
Instructor
Joined: Feb 2002
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From: C5 Land
Re: knocking sound when engine is cold (ersatz928)
Well, check this out! http://www.angelfire.com/tx5/gmpistonslap/
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Team Owner
Joined: Jul 2001
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From: Various places in Southern California.
Re: knocking sound when engine is cold (00c5coupe)
What year is your car? I believe around April of 2001 they started using the coated pistons to prevent piston slap. I know my car was produced after this running change and it is quiet.
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Re: knocking sound when engine is cold (Duck916)
Thanks to all for your respond. My vette is a 2k model and had 24k miles. I don't remember hear this sound before but it wasn't that bad like the video above. I can hardly hear it (might be just me not the car...). I've been using different brand of oil filters, the one i have on the car is mobil 1. Will see if anything happen....
Thanks again.
Thanks again.
Pro
Joined: Aug 2000
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From: EAST ROCKAWAY NY USA
Re: knocking sound when engine is cold (00c5coupe)
I have a slite ticking when I start car in the AM after a few min. it go away .If I do not do any thing will there be any problems later on ? :flag :flag :flag
Glenn
Glenn
