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Old Oct 29, 2015 | 12:50 PM
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I have an 03 with 105,000 miles. When I start it up when it's cold I get a knock on the right side. Once it warms up it goes away. Any ideas ? Thanks guys.
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Old Oct 29, 2015 | 12:59 PM
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Originally Posted by HERK
I have an 03 with 105,000 miles. When I start it up when it's cold I get a knock on the right side. Once it warms up it goes away. Any ideas ? Thanks guys.
Possible theories:
Oil pump bad
Low oil
Valve train such as lifter, pushrods etc.
Bad spark plug and or wire.

Its really hard to say, a video will definitely help.

I had the same issue but it turned out to be the ac belt tensioner, so I cut it off.

Hope this gives an idea where to look.
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Old Oct 29, 2015 | 03:14 PM
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since you said what side its on it might be an exhaust leak i've herd more then a few that sounded like a engine knock when cold and gos away when warmed up

if it had piston slap you would of herd it a lot sooner then 105k
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Old Oct 29, 2015 | 07:48 PM
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Originally Posted by 8VETTE7
Sounds like symptoms of piston slap, a common noise on the LS and many other modern engines when cold.
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Old Oct 29, 2015 | 07:56 PM
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You don't say just how long you have had the car. It does sound like piston slap, but if you've had it a long time, you should have heard it before now. Check the things above and see if they can be ruled out. Good luck - hope it is nothing serious.
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Old Oct 29, 2015 | 09:01 PM
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the few LSx engine i had that had piston slap had it on both side, every one i herd you could not tell witch side it was since he said witch side it was lead me to think its a exhaust header/manifold leak my last z06 had a leak i really though i had a rod knock

i'd inspect the exhaust for leaks if that was all good i'd pull the valve covers to see how that looks? might be a stubborn lifter when cold lazy pumping up

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Old Oct 29, 2015 | 10:57 PM
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Thanks for all the help guys.
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