Need advice..Engine Knock

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afpj

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there's a thread on this forum about using tcw3 2 cycle oil into the gas tank that helps with the piston slap noise. haven't personally tried it.
 

Diggerdan11

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I had the same problem with my Tahoe i just bought in January with 140k. Its sounded really bad like a diesel until it was warm.

I just wen to Autozone and bought and Additive. I think that brand was CD-2its and Oil Detergent. It worked great and now my engine purrs like a kitten.

When its time to change my oil, im going to go Full Synthetic and They also make additives that you put in in place of one of the quarts of oil.
 
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TWITCH101

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there's a thread on this forum about using tcw3 2 cycle oil into the gas tank that helps with the piston slap noise. haven't personally tried it.

interesting???have a link????
 

lowAZhoe

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LOL piston slap??? thats the funniest thing i have ever heard guys...ive been working on cars for 10 years and have never told any of my customers thats its normal piston slap noise....

try replacing your oil pickup tube o-ring. remove oil pan, remove pickup tube, replace oring, reinstall pickup tube, replace pan gasket, and fixed. these LS engines the orings get worn and lack oil pressure on startup.
 
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TWITCH101

TWITCH101

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LOL piston slap??? thats the funniest thing i have ever heard guys...ive been working on cars for 10 years and have never told any of my customers thats its normal piston slap noise....

try replacing your oil pickup tube o-ring. remove oil pan, remove pickup tube, replace oring, reinstall pickup tube, replace pan gasket, and fixed. these LS engines the orings get worn and lack oil pressure on startup.

How costly is this??? what parts will I need other than the o-ring? for instance will I need another oil pan gasket?
 

lowAZhoe

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How costly is this??? what parts will I need other than the o-ring? for instance will I need another oil pan gasket?

oil pan gasket, oring, and engine sealant (gm sealnt recommended). pan gasket is about $40, oring is a few bucks, and sealant about $20
 
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TWITCH101

TWITCH101

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cool...and its just a simple drop the oil pan and its all right there???
 

lowAZhoe

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cool...and its just a simple drop the oil pan and its all right there???

yea pretty much. if u have 4x4 u will have to unbolt the front diff and let it drop down...dont unbolt the axles and it will stay up there. crossmember has to come out and then theres a harness on the front with one 10mm bolt, a clip holding trans cooler lines on passenger side and 2 bolts on on each side in the rear holding a plastic filler panel on each side. if u have oil cooler lines there r 2 10mm bolts on drivers side, if not its just blocked off...once the pan is off theres 2 13mm nuts and a 10mm bolt holding the tube to the oil pump in front.

2wd pays us 2 hours, i can knock them out in about 20 minutes...4x4 pays 4 hours, can be done in about 40 minutes....but ive done tons of them...
 
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TWITCH101

TWITCH101

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nice thanks for the help...I'll have to try this next oil change which is really soon. How confident are you that it will fix my prob?
 

chauncey0337

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LOL piston slap??? thats the funniest thing i have ever heard guys...ive been working on cars for 10 years and have never told any of my customers thats its normal piston slap noise....

try replacing your oil pickup tube o-ring. remove oil pan, remove pickup tube, replace oring, reinstall pickup tube, replace pan gasket, and fixed. these LS engines the orings get worn and lack oil pressure on startup.

My oil pressure seems fine on startup. Could there be something else causing this awful noise on cold starts.
 

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