Full throttle rattles
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Joined: Dec 2006
Posts: 76
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From: Florida
Full throttle rattles
I have noticed that the last few times I have floored my 04 that I hear cylinder heads rattling or knocking at high RPM's!!! Anyone have the same noise and know if it is normal or Ihave a problem... I have a vortex air rammer port/polished BPP throttle bod and a chip for under hood work... and exhaust but dont think that will cause the sound....thanks
Last edited by 04_C5_SLAMMED; Sep 1, 2007 at 03:56 AM.
Melting Slicks
Joined: Oct 2006
Posts: 3,447
Likes: 6
From: Los Angeles
I have noticed that the last few times I have floored my 04 that I hear cylinder heads rattling or knocking at high RPM's!!! Anyone have the same noise and know if it is normal or Ihave a problem... I have a vortex air rammer port/polished BPP throttle bod and a chip for under hood work... and exhaust but dont think that will cause the sound....thanks
Last edited by DefenderC5; Sep 7, 2007 at 12:26 AM.
Melting Slicks
Joined: Oct 2006
Posts: 3,447
Likes: 6
From: Los Angeles
Or was it the superchip programmer rather than an actual "chip" that spliced in somewhere? Did you edit the tables yourself. I still think you have a lean condition. If it editted the tables, try reverting them back to stock. If this is the case, it probably did help the low end, but you may still have a lean condition in the upper RPM tables. There are others far more knowledgeable on C5 tunes than me though, try posting the question in the Scan/Tune forum too.
Wire/plugs should be fine, they are designed to go to 100k. Mine has 65k and I drive it hard every now and then, stock plugs/wires.
Last edited by DefenderC5; Sep 7, 2007 at 12:33 AM.
Le Mans Master
Joined: Aug 2001
Posts: 8,145
Likes: 1
From: Bradenton FLORIDA
Again, the PCM is programmable... there is no need for a chip. My money is on the Superchip (piggyback unit?) Take it off, and drive it around for a few days and see if it gets better. If you want the car to run better via the computer, have the PCM tuned. There are some tuners that do mail order tunes on the forum for around $150. A dyno tune would be best and tailored to your car.
Or was it the superchip programmer rather than an actual "chip" that spliced in somewhere? Did you edit the tables yourself. I still think you have a lean condition. If it editted the tables, try reverting them back to stock. If this is the case, it probably did help the low end, but you may still have a lean condition in the upper RPM tables. There are others far more knowledgeable on C5 tunes than me though, try posting the question in the Scan/Tune forum too.
Wire/plugs should be fine, they are designed to go to 100k. Mine has 65k and I drive it hard every now and then, stock plugs/wires.
Or was it the superchip programmer rather than an actual "chip" that spliced in somewhere? Did you edit the tables yourself. I still think you have a lean condition. If it editted the tables, try reverting them back to stock. If this is the case, it probably did help the low end, but you may still have a lean condition in the upper RPM tables. There are others far more knowledgeable on C5 tunes than me though, try posting the question in the Scan/Tune forum too.
Wire/plugs should be fine, they are designed to go to 100k. Mine has 65k and I drive it hard every now and then, stock plugs/wires.
Give us a call, you are not to far away and if you run it with detonation under full throttle to many times you will have engine damage from it. It does not sound like the knock sensors are working properly...or your "chip" is causeing it.
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Instructor
Joined: May 2004
Posts: 145
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From: North providence RI
Hey Guys,
I have a 99 coupe and i am not sure if it is the same noise, but when i get on it and the rpms start going up i also get a "tapping" noise. It will not do it at a low rpm. To me it sounds like lifters, but i am sure it is not that. I have never changed the plug/wire since i have owner it, four years now, but it only has 25k on it. Any idea what it could be?
Thanks
I have a 99 coupe and i am not sure if it is the same noise, but when i get on it and the rpms start going up i also get a "tapping" noise. It will not do it at a low rpm. To me it sounds like lifters, but i am sure it is not that. I have never changed the plug/wire since i have owner it, four years now, but it only has 25k on it. Any idea what it could be?
Thanks
Melting Slicks
Joined: Oct 2006
Posts: 3,447
Likes: 6
From: Los Angeles
Hey Guys,
I have a 99 coupe and i am not sure if it is the same noise, but when i get on it and the rpms start going up i also get a "tapping" noise. It will not do it at a low rpm. To me it sounds like lifters, but i am sure it is not that. I have never changed the plug/wire since i have owner it, four years now, but it only has 25k on it. Any idea what it could be?
Thanks
I have a 99 coupe and i am not sure if it is the same noise, but when i get on it and the rpms start going up i also get a "tapping" noise. It will not do it at a low rpm. To me it sounds like lifters, but i am sure it is not that. I have never changed the plug/wire since i have owner it, four years now, but it only has 25k on it. Any idea what it could be?
Thanks
If any of this sounds like your condition, and if it was my car, I would do a seafoam treatment like mentioned above. It's easy to do, plenty of threads on it if you do a search.
Race Director
Joined: Jul 2004
Posts: 16,795
Likes: 62
From: Lake Havasu City, AZ
It could be "h" pipe rattle.
Many have laughed at me for this but the H" pipe interior is not completely hollow ... ie it has a reduced internal diameter that can cause an exhaust rattle at WOT...
GM has recognized this and now sells a C5 replacement X pipe. They buy from Corsa for around $369 it solves the exhaust rattle.....
Many have laughed at me for this but the H" pipe interior is not completely hollow ... ie it has a reduced internal diameter that can cause an exhaust rattle at WOT...
GM has recognized this and now sells a C5 replacement X pipe. They buy from Corsa for around $369 it solves the exhaust rattle.....
Race Director
Joined: Jan 2003
Posts: 19,802
Likes: 0
From: San Antonio Texas
St. Jude Donor '05-'06-'08
Instructor
Joined: May 2004
Posts: 145
Likes: 0
From: North providence RI
Thanks for the words Defenderc5.
I am the second owner and the car had only 13k on it when i bought it. To me it sounds more rythmic as you said.....not a rattle. I do not know what a "seafoam" treatment is, but i am going to look it up right now. I have to say that i really do not get on it since this started, as i am just not sure what it is. The car runs fine and all....just do not like that sound.
Tweakd
I am the second owner and the car had only 13k on it when i bought it. To me it sounds more rythmic as you said.....not a rattle. I do not know what a "seafoam" treatment is, but i am going to look it up right now. I have to say that i really do not get on it since this started, as i am just not sure what it is. The car runs fine and all....just do not like that sound.
Tweakd
