Engine knocking at first start up
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Engine knocking at first start up
I noticed that my 07 was knocking fairly loud today when i first cranked it up. 5 minutes later the knock was gone. Ive heard lifter knock at first start before but this was fairly loud. Could it be that it just needed time to pump the oil to the top of the engine? 2007 Z51 LS2 26500 miles. only mod is borla exhaust. 6 speed. only 2200 miles on the oil change.
Last edited by Clint McFarland; May 26, 2011 at 08:20 PM.
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From: Howell Michigan
St. Jude Donor '09-'10-'11
Add a little more info about your car. How many miles on it, what engine, any mod's, is this new or has it done this for a while, has any work been done recently including oil change, auto or manual???? This would help.
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2007 Z51 LS2 26500 miles. only mod is borla exhaust. 6 speed. only 2200 miles on the oil change. thanks for the reply
Last edited by Clint McFarland; May 26, 2011 at 08:05 PM.
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From: Howell Michigan
St. Jude Donor '09-'10-'11
While it is making the noise rev the engine in neutral up to about 1100 to 1200 rpm to see if the knock gets loader. If it does and then after about 5 to 10 minutes goes away it will most likely be piston slap.
The noise is the worse part, as it really doesn't hurt anything. Short of replacing the pistons, there's not really much that can help. I have a 2000 5.7L with piston slap noise in my C5. It has 58k on the engine. It started making the knock noise at 20K miles.
Last edited by Eric D; May 26, 2011 at 08:28 PM.
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First thing, if you haven't, check your oil level. Next, if you have something to upload a wav file of the noise it would help, but if I were to guess, which this is, I would say most likely piston slap noise.
While it is making the noise rev the engine in neutral up to about 1100 to 1200 rpm to see if the knock gets loader. If it does and then after about 5 to 10 minutes goes away it will most likely be piston slap.
The noise is the worse part, as it really doesn't hurt anything. Short of replacing the pistons, there's not really much that can help. I have a 2000 5.7L with piston slap noise in my C5. It has 58k on the engine. It started making the knock noise at 20K miles.
While it is making the noise rev the engine in neutral up to about 1100 to 1200 rpm to see if the knock gets loader. If it does and then after about 5 to 10 minutes goes away it will most likely be piston slap.
The noise is the worse part, as it really doesn't hurt anything. Short of replacing the pistons, there's not really much that can help. I have a 2000 5.7L with piston slap noise in my C5. It has 58k on the engine. It started making the knock noise at 20K miles.
Will work for HPDE time.
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From: Orlando FL
First thing, if you haven't, check your oil level. Next, if you have something to upload a wav file of the noise it would help, but if I were to guess, which this is, I would say most likely piston slap noise.
While it is making the noise rev the engine in neutral up to about 1100 to 1200 rpm to see if the knock gets loader. If it does and then after about 5 to 10 minutes goes away it will most likely be piston slap.
The noise is the worse part, as it really doesn't hurt anything. Short of replacing the pistons, there's not really much that can help. I have a 2000 5.7L with piston slap noise in my C5. It has 58k on the engine. It started making the knock noise at 20K miles.
While it is making the noise rev the engine in neutral up to about 1100 to 1200 rpm to see if the knock gets loader. If it does and then after about 5 to 10 minutes goes away it will most likely be piston slap.
The noise is the worse part, as it really doesn't hurt anything. Short of replacing the pistons, there's not really much that can help. I have a 2000 5.7L with piston slap noise in my C5. It has 58k on the engine. It started making the knock noise at 20K miles.
