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Old 01-25-2017   #11
Dynomite
 
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Default Re: 91 Engine Noise

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Originally Posted by koshe2 View Post
Is that an immediate concern?? I am hearing that its not all that unusual
I noticed Piston Slap in my 4x4 Toyota Truck at less than 50,000 miles when I bought it used.....
Now at 260,000 miles Piston Slap is still there
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Old 01-25-2017   #12
koshe2
 
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Location: River Falls, WI
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Default Re: 91 Engine Noise

Some people suggest that the car has carbon build up. Does anyone have a good way to get rid of that? I have read of someone spraying seafoam through the throttle body....
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Old 01-27-2017   #13
cuisinartvette
 
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Default Re: 91 Engine Noise

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Originally Posted by koshe2 View Post
Is that an immediate concern?? I am hearing that its not all that unusual
Youre right its not
Slight clucking sound when you start it many of them do it dont sweat it keep driving it.
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Old 01-27-2017   #14
Hib Halverson
 
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Default Re: 91 Engine Noise

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Originally Posted by 32valvesftw View Post
Carefully use a long screwdriver like a stethoscope put your ear to the handle you will be able to get a good idea of what section of the engine its coming from. Also have you done a recent oil change, if not maybe do so and look for metal dust or bits in the oil. Noises like that time to find.
Much better than the screw-driver-handle-in-ear tool is a real mechanic's stethoscope. The sound transmission is far better. One of the better units available, and the one I use in my shop, is made by Lisie PN 52750. You can find it at RockAuto.com for around 16 bucks

Also, unless your oil filter is fully bypassing, you're not going to find any powder in the oil. If you find "bits" in the drain oil, you have far worse problems than cold piston knock and need to get the motor out for repair.
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Old 01-27-2017   #15
koshe2
 
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Default Re: 91 Engine Noise

It gets better when the oil warms up, but its still there. Sounds like a lifter.
Has 10-30 mobile 1 and a wix filter
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Old 01-28-2017   #16
Hib Halverson
 
Join Date: Jun 2005
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Default Re: 91 Engine Noise

Without hearing it I'd say it's cold piston knock, which some call piston "slap".

A certain amount of cold piston knock is typical of LT5s. It should almost go away entirely when the oil temperature is normal.
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