40 weight & piston slap

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Jul 28, 2006 | 06:19 PM

1999 SS

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40 weight & piston slap

my 00 TA has piston slap pretty bad and about a weak ago i changed my oil to straight nonsynthetic 40 weight and the noise is about 90%+ gone.

Jul 28, 2006 | 07:13 PM

ls1wfo

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yeah, seems like I read somewhere that if you have really bad slap to change to castrol 10W40 & it would completely eliminate it.

Jul 28, 2006 | 10:27 PM

BJM

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The higher viscosity oil has a lot more drag on the con rod bearings so the piston is planted against the cylinder wall more firmly, quieting the slap. Be careful revving when cold in cold weather, the oil pump loads will be a lot higher and the oil will struggle to get everywhere through the engine until it warms up.

Jul 29, 2006 | 02:10 AM

PREDATOR-Z

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From: BFE

I run 40 weight in all my LS motors (Mobil1-0W40)

Jul 29, 2006 | 12:02 PM

black01_WS6

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I am running the Royal Purple 10W40 and am not burning as much oil, and pressure is up, and it seems like the car is runnign better than running the 0W40 Mobil 1. I also have 99,xxx miles.

Jul 30, 2006 | 03:08 AM

SSDude

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Quote:

Originally Posted by PREDATOR-Z

I run 40 weight in all my LS motors (Mobil1-0W40)

M1 0w-40 will shear down to a 30wt by design with 2,000 miles of usage. It does not thicken back up to a 40wt until after about 10,000 miles.

Jul 30, 2006 | 06:53 AM

PREDATOR-Z

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From: BFE

In all the years I've used it, I never had any lubrication issues or lifter issues. Oil pressure is always within parameters.
On my new built BTW, it is the first time I use a ported pump. All my other motors just ran LS6 stock pumps with no issues.
My cylinder hones have always been in top shape, cam lobe wear etc....
In my environment, it works well as per my experience.