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Discussion Starter #1
On '03's to '05's, a certain characteristic with these engines with cold starts in the morning, is a tapping sound, which disappears after 3-4 minutes of warm up. It sounds like a lifter, but it's actually the piston slapping against the cylinder wall. GM tried to rectify it by coating it with Teflon, but when talking to most of the mechanics about it, this is a common characteristic of this engine. Being it's an aluminum block, it sounds even louder than the old cast iron blocks.

So if you have a magnet drain plug, when you change your oil you may see fragments of metal on the oil plug tip. Not to be concerned, it's just slight shavings from the piston walls. My '02 Z06 does the same thing. I spoke to Mike Kotze, one of the top mechanics in my area, and he said that some of the engines he tore down, did not show any damage to the piston teflon coating, but some slight dullness on the sides of the walls. To his experience, these engines have been around for a couple of years and have never had any problems and have been very dependable.
 

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dittonzssr said:
it's the lifters
It probably is piston noise, the piston skirt is very short on these engines and they do make a little noise on a cold start but is not a cause for alarm.
 

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Hmmm

Maybe I missed something but I'm not sure how a magnetic drain plug would attract aluminum from the pistons or the block???
 

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Discussion Starter #5 (Edited)
41chevcoe said:
It probably is piston noise, the piston skirt is very short on these engines and they do make a little noise on a cold start but is not a cause for alarm.
Exactly. :thumbs And as the engine warms up, the piston skirt expands which makes a tighter fit and oil starts to circulate and saturates the walls and the skirt, hence the noise starts to disappear. On some newer engines they're building, especially the Harley Davidson engines, they are now injecting oil from the bottom of the pistons which is eliminating wear and giving better lubrication.
 

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Discussion Starter #6
hdflstf said:
Maybe I missed something but I'm not sure how a magnetic drain plug would attract aluminum from the pistons or the block???

I'm not saying that the magnetic drain is picking up any aluminum, because it can't pick up aluminum. There's very little steel in the new development of engines today, but the cylinder walls are steel. What it's picking up is the shavings from the skirts hitting the sides of the cylinder walls when the piston skirt slaps against the cylinder walls, especially with cold starts when the oil is all drained down and there is a very thin layer of oil on the cylinder walls and skirts. It then falls into the oil, where it is picked up by the magnet in the drain plug. The magnet is doing it's job by collecting any metal so it doesn't get mixed in with the oil and scar any bearings or rings. Cold starts is the biggest problem in wearing internal parts. :ssr
 

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RetroCarGuy530
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My 03 SSR had some "light piston slap" but my 05 SSR has far more than the 03 did.

After about five minutes of running and the engine temp gets above 160 (or so) it seems to fade out. It's not a sound that makes one feel great about their engine, but as long as it's "normal", I'll just have to learn to accept this noise. I would assume that since the 05 Corvette has the same basic LS2 engine, they too experience this "piston slap" noise on cold startup?
 

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shiftz33 said:
My 03 SSR had some "light piston slap" but my 05 SSR has far more than the 03 did.

After about five minutes of running and the engine temp gets above 160 (or so) it seems to fade out. It's not a sound that makes one feel great about their engine, but as long as it's "normal", I'll just have to learn to accept this noise. I would assume that since the 05 Corvette has the same basic LS2 engine, they too experience this "piston slap" noise on cold startup?
I've been told the Corvette's make the same noise and it's normal.
 

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A Little BIG JIM
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Slap and Tink..........normal?

I never thought a Fifty Thousand Dollar Vehicle that Slaped and Tinked was normal? But I love her the same..I DO! :lol :lol :lol :lol
 

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RetroCarGuy530
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I agree. A $40K to $50K automobile shouldn't be making some of these "noises".

If I can just get the service department to move/eliminate the rear end whine noise @ 65 to 75, I'll be a truly happy SSR owner.
 

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I do believe that the tapping is the lifters/valvetrain and not piston slap. The engine would be more prone to piston slap if the pistons were forged rather then cast. This is the reason most manufacturers use the cast pistons vice forged.
 

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I used to have a Z06. It was well known at the time that there was a piston slap problem under cold startup conditions. This is why GM added the coating to some versions of the 6.0 liter engine later.

Jim G
 

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Just a quick comment here...

How many of you heard this "piston slap" when you test drove your baby? If it WAS a normal thing, why doesn't it start until AFTER break in.
 
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