Standard Cylinder Slap or Not?
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Standard Cylinder Slap or Not? I have been trying to get a little help with this but haven't been able to get any help.
I have a 2004 5.3L LM7 with 91,000 miles.
I parked the truck late last fall before it got cold and never heard a noise. Recently I moved the truck and decided to take it around the block to get things warmed up. The temp was in the 40's, I noticed that between 2000 and 2200 RPM I could hear a knock from the motor. Which went away after a few minutes after the truck warmed up. I was able to repeat this over a few days with the same result. After it warms up I can rev the motor to 4000 rpm and it is quiet. When it does make the noise it only knocks between those RPM's when cold.
This is my first year with this truck so I do not know if it generally does this when it is cold. Do you think this is the normal cylinder slap or something more? Steps I can take to diagnosis?
Thanks.
I have a 2004 5.3L LM7 with 91,000 miles.
I parked the truck late last fall before it got cold and never heard a noise. Recently I moved the truck and decided to take it around the block to get things warmed up. The temp was in the 40's, I noticed that between 2000 and 2200 RPM I could hear a knock from the motor. Which went away after a few minutes after the truck warmed up. I was able to repeat this over a few days with the same result. After it warms up I can rev the motor to 4000 rpm and it is quiet. When it does make the noise it only knocks between those RPM's when cold.
This is my first year with this truck so I do not know if it generally does this when it is cold. Do you think this is the normal cylinder slap or something more? Steps I can take to diagnosis?
Thanks.
Teching In
Joined: Sep 2013
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From: Orange county
I know for a fact that "piston slap" which is a nickname for when the pistons scrape the walls when moving (the walls condense a little due to being low temp and being aluminum) I have piston slap myself, not too bad/big of a deal (just warm up your car before driving).
1999 CAMARO
lsx
H/C/I
LS6 CRANK
HARDENED PUSHRODS & ROCKER ARMS
PORTED TB
PORTED INTAKE
LT'S
X-PIPE W/ BULLET MUFFLERS DUMPED
1999 CAMARO
lsx
H/C/I
LS6 CRANK
HARDENED PUSHRODS & ROCKER ARMS
PORTED TB
PORTED INTAKE
LT'S
X-PIPE W/ BULLET MUFFLERS DUMPED
On The Tree
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From: SE Indiana
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My understanding is that cylinder slap is at idle on a cold start up and it goes away as the motor warms up. My noise is not present at start up, it only makes noise at 2000-2200 Rpms and then goes away after warm.
I would think a rod knock or spun bearing would get louder as the motor warmed up.
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