Clacking sound on cold cranks! HELP PLEASE! - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

CamaroKitty · 06-26-2009, 10:52 AM

When I first crank, I have a sporatic clacking noise that will continue until the car idles down. This takes a few seconds only. It only happens on cold cranks. After the first crank of the day...it doesn't do it again. Also..you can har some belt nosie non stop from the time of crank and even after it idles down. Any thoughts??

camaro5 · 06-26-2009, 01:35 PM

It's called piston slap.

Common in many GM engines.

Quote:

Around 1998, GM switched from a "Select Build" method of manufacturing and/or assembling engines to a "Net Build" method, in order to save money on manufacturing and/or assembly.

In the Select Build process, pistons and cylinders are matched for size and fit. GM's new "Net Build" method of manufacturing and/or assembly, in contrast, assumes all pistons will fit equally well in all cylinders and does not allow for variations in the size of engine cylinders or pistons.

The pistons of slightly varying size (all within spec) are not individually matched with the cylinders of slightly varying size (all within spec).

Excessive “piston slap” occurs because an automobile manufacturer (GM) designs and/or manufactures a engine in which the clearance between the piston and cylinder bore is too great.

Essentially, the piston moves sideways and “slaps” or “knocks” hard against the cylinder bore.

http://www.pistonslap.com/

.

CamaroKitty · 06-26-2009, 02:19 PM

So what do you do?? It sounds horrible. Is it something that the dealer needs to go in and fix or do you just deal?? It didn't do it for about the first few hundred miles.

camaro5 · 06-26-2009, 06:20 PM

Quote:

Originally Posted by CamaroKitty

So what do you do?? It sounds horrible. Is it something that the dealer needs to go in and fix or do you just deal?? It didn't do it for about the first few hundred miles.

My then new, 1984 Camaro Z28 did it too.

I would just deal with it. I bought a new Corvette knowing all about it.

I don't like it though...

The link I posted has all the info, as they are dedicated anti piston-slappers.

-

caramaro1969 · 07-02-2009, 06:03 PM

yeah it's a ls motor thing.it has been known to do it with other gm motors.no worries

Ject · 07-02-2009, 06:08 PM

I have the same thing on my 2004 Silverado, nice little knocking sound but it is consistently there.. Faint.. but there all the time.

patriotpa · 07-02-2009, 06:11 PM

I doubt that "piston slap" is the issue. More likely noisy lifters until the oil pumps up top. No big deal. Still, it doesn't hurt to get the dealer to have a look.

The site listed is there to MAKE MONEY. Lawyers run it to advertise LAWSUITS so THEY can get paid..

Rogue Leader · 07-02-2009, 06:22 PM

Yeah those sites go nuts over the piston slap issue and say it destroys the engine... Ive had 2 LS motors with 100k on them and both pistion slapped while idling cold, neither one used a drop of oil, and both ran mint otherwise...

Like he said lawyers trying to make money...

PsyDoc · 07-02-2009, 06:23 PM

Quote:

Originally Posted by caramaro1969

yeah it's a ls motor thing.it has been known to do it with other gm motors.no worries

No worries? Really? So, a piston that wobbles in the cylinder bore is nothing to worry about?

06-26-2009, 10:52 AM	#1
CamaroKitty Drives: 2010 Silver Ice 2LT RS V6 Join Date: Jun 2009 Location: Echo, Louisiana Posts: 12	Clacking sound on cold cranks! HELP PLEASE! When I first crank, I have a sporatic clacking noise that will continue until the car idles down. This takes a few seconds only. It only happens on cold cranks. After the first crank of the day...it doesn't do it again. Also..you can har some belt nosie non stop from the time of crank and even after it idles down. Any thoughts??

07-02-2009, 06:08 PM	#6
Ject aka Patrick Drives: '10 Camaro 2SS '04 Silverado Join Date: Jan 2009 Location: Derby Kansas Posts: 3,072	I have the same thing on my 2004 Silverado, nice little knocking sound but it is consistently there.. Faint.. but there all the time. __________________ Current Modifications: Your average Bolt-ons & Suspension Upgrades GForce Engineering: 9" Rear End, Strange Pro Iron Case w/Moser Nodular 3.70:1 Detroit locker, 3.5" Solid Drive Shaft

07-02-2009, 06:22 PM	#8
Rogue Leader Iatefiberglassinsulation Drives: 2010 Camaro 2SS M6 Join Date: Oct 2008 Location: Long Island Posts: 3,601 View My Garage	Yeah those sites go nuts over the piston slap issue and say it destroys the engine... Ive had 2 LS motors with 100k on them and both pistion slapped while idling cold, neither one used a drop of oil, and both ran mint otherwise... Like he said lawyers trying to make money... __________________ 2010 Chevrolet Camaro SS - was daily driver, now toy 2020 Alfa Romeo Giulia Quadrifoglio - Daily Driver 2017 Mercedes Benz GLE 350 - Wifes Car 2008 Chevy Silverado 2500 HD LT 6.0 - Tow Vehicle 1991 Alfa Romeo 164S - Project Car 1994 Volkswagen Golf - Race Car "Like" my race team on Facebook: http://www.facebook.com/farfrumwinnin

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06-26-2009, 02:19 PM	#3
CamaroKitty Drives: 2010 Silver Ice 2LT RS V6 Join Date: Jun 2009 Location: Echo, Louisiana Posts: 12	So what do you do?? It sounds horrible. Is it something that the dealer needs to go in and fix or do you just deal?? It didn't do it for about the first few hundred miles.

07-02-2009, 06:03 PM	#5
caramaro1969 Drives: 69,82,84 & 10 camaros,87 GMC,07z06 Join Date: Nov 2007 Location: arkansas Posts: 328	yeah it's a ls motor thing.it has been known to do it with other gm motors.no worries

07-02-2009, 06:11 PM	#7
patriotpa Account Suspended Drives: 02 Silverado, 09 Vue, 10 1SS Join Date: Aug 2008 Location: Tired of apologizing when we should be kickin' butt! Posts: 1,966 View My Garage	I doubt that "piston slap" is the issue. More likely noisy lifters until the oil pumps up top. No big deal. Still, it doesn't hurt to get the dealer to have a look. The site listed is there to MAKE MONEY. Lawyers run it to advertise LAWSUITS so THEY can get paid..