need advice
Thread Starter
Heel & Toe
Joined: Jul 2007
Posts: 24
Likes: 0
need advice
have a c5 with 38000 miles --when cold it has aclicking or knocking until it is warm then clear---carbon on pistons-labor knock-valves??? what should i do to clear it up?? also the traction control button--if i hold it down --competitive driving is displayed??? what does this mean?? curt05
Race Director
Joined: Jan 2007
Posts: 18,643
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From: Norman Oklahoma - The Only State in the Union with no Blue Counties!
Do a search on "piston knock or slap" Might be your problem, not a major one for now! Hopes this gives you some directions to head into!
When u turn off tc you are now in Comp mode,,,,no rear wheel spin compensation. My advice,,,leave tc on unless you're at a track and only then after you gain serious experience!
When u turn off tc you are now in Comp mode,,,,no rear wheel spin compensation. My advice,,,leave tc on unless you're at a track and only then after you gain serious experience!
Last edited by Silverbullet00; Jul 15, 2007 at 11:51 PM.
Burning Brakes
Joined: Oct 1999
Posts: 836
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From: Colorado Springs, Colo., USA
The "knocking" until warm up has been written about on this forum and the consensus seems to be that it is normal for many C5s to do this. My old C4 did it, too, and it was the FI system. Not an issue.
The "competition mode" reduces the interaction of the active handling and traction control systems, as I recall. Again, a search of the forum will turn up lots on this topic, too.
Good questions!
The "competition mode" reduces the interaction of the active handling and traction control systems, as I recall. Again, a search of the forum will turn up lots on this topic, too.
Good questions!
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I agree it could be piston slap. Usually not a problem.
Check your owners manual to see if there is a writeup on use of the competitive driving mode.
Check your owners manual to see if there is a writeup on use of the competitive driving mode.
Thread Starter
Heel & Toe
Joined: Jul 2007
Posts: 24
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curt05
do they make an additive--such as a disolving solvent for carbon buildup--that would be recommended?? what name? the traction control ==competitive driving--does it alter the chip to give more hp? why would it not give two wheel traction?? havent had a clearcut answer on this --maybe imagination but it seems to have more power in this mode----three month 70 year old owner!
Burning Brakes
Joined: Oct 1999
Posts: 836
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From: Colorado Springs, Colo., USA
do they make an additive--such as a disolving solvent for carbon buildup--that would be recommended?? what name? the traction control ==competitive driving--does it alter the chip to give more hp? why would it not give two wheel traction?? havent had a clearcut answer on this --maybe imagination but it seems to have more power in this mode----three month 70 year old owner!
No the Competition Mode does nothing (that I have ever read of) to increase ennginne output. It just makes it lots and lots easier for you to get in trouble because the traction control and active handling systems' intervention to save your behind are reduced. I leave my '02 coupe in the normal mode.
Instructor
Joined: Feb 2007
Posts: 185
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From: Memphis TN
do they make an additive--such as a disolving solvent for carbon buildup--that would be recommended?? what name? the traction control ==competitive driving--does it alter the chip to give more hp? why would it not give two wheel traction?? havent had a clearcut answer on this --maybe imagination but it seems to have more power in this mode----three month 70 year old owner!
Last edited by MemphisBlu; Jul 16, 2007 at 01:42 PM. Reason: sp
Burning Brakes
Joined: Oct 2006
Posts: 874
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From: Campbell Ca
I have an 02 with 15K and it sounds like a diesel until it warms up to about 160. My understanding was that it was Piston Slap, whereas the piston skirts where slightly smaller to accomodate expansion and with the angle of the cylinder bore it would cause a slight knocking sound until they heat up and expand. Well, that's what I've read on here and heard from 2 mechs. Personally of all the Chevy's I've owned, I've never heard this before but then again, I've never owned a 02 LS1 motor.
Once I loaded my 12disc with all my favorites, I don't hear the noise anymore!
I should have been a mechanic!!
Once I loaded my 12disc with all my favorites, I don't hear the noise anymore!
I should have been a mechanic!!
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Thread Starter
Heel & Toe
Joined: Jul 2007
Posts: 24
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hey rocket
what you said makes sense
after talking to a corvette mechanic -these cars need blowing out fairly often and with the close tolerances--piston to the cyclinder head-corbon can become a problem--will try seafoam in the gas----as for the competitive driving mode==it actually reprograms the chip for added power--like you would buy a performance chip at auto zone--and that to me makes more sense as it takes time after you hold the button down--hey why so long? anyhow i have a volume control on my radio also and thanx for all the input
after talking to a corvette mechanic -these cars need blowing out fairly often and with the close tolerances--piston to the cyclinder head-corbon can become a problem--will try seafoam in the gas----as for the competitive driving mode==it actually reprograms the chip for added power--like you would buy a performance chip at auto zone--and that to me makes more sense as it takes time after you hold the button down--hey why so long? anyhow i have a volume control on my radio also and thanx for all the input
Pro
Joined: May 2005
Posts: 697
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From: Up North Wisconsin
Motor noise is the norm these days. The 6.0 in my 2500HD sounds like it's going to fly apart. I had a 5.3 in another Chev pickup and it was the same. I also had a Ford pickup with a 4.6, it was no better.
Last edited by 00247; Jul 17, 2007 at 11:26 AM.