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flutter of doom!

m3ta77ica

New member
so i have a 2005 grand prix gtp. about a month ago it started making this flutter noise. It sounds like a flutter/knock. Say you were standing far from a construction site and you hear a jackhammer. sounds like that. well it does it when i ease into the gas, when the cruise is set going up hills, and if i put it in drive and hold the gas at 2,000 rpm. i got my trans flushed and a new filter. i then got some sea foam trans tune and it made it go away for about a day. but it is back. i took it to the dealership and they had it for a week and thought it was my cat or my egr valve so my warranty got me free cat and egr cleaned but its still not fixed and they gave me a bull**** line that its a natural noise to those motors and that the plastic engine cover makes it go away so i put the cover back on and its still there. anyone please anyone if you have an idea whats going on let me know. :th_sign-beamme:
 


Sounds like a broken ring land, 2nd ring to be exact. Had the same thing happen to me before on my 1970 Buick 455. The cause was to much timing, too much compression, too low octane. The ring land between the second and top piston ring was broken in three pieces. Didn't cause any damage. You can check for this without disasembling the engine by doing a simple cranking compression test. Also you will see some puffs of blow by out the valve oil fill tube. I hope that is not your problem, it'd better if it just a flexplate. One question, How hard you been driving it?



Dean
 
Wow does that sound bad!

I would get a compression test on each cylinder immediately.

It does sound like the trans but then as you moved in on the header pipe, it sounded like a rattle within it. Not sure, never heard that before. Stop by a trans shop too and have them give a listen, worth a stop.
 
Wow does that sound bad!

I would get a compression test on each cylinder immediately.

It does sound like the trans but then as you moved in on the header pipe, it sounded like a rattle within it. Not sure, never heard that before. Stop by a trans shop too and have them give a listen, worth a stop.

that video would be a broken flexplate...not my car, not op, I was using it solely for an example.
 


I would guess m3ta77ica's problem is a loose or broken flexplate. To sound like a jackhammer it has to almost be a flexplate.
 
its fairly quiet tho its noticeable but quiet. and its only when i barely accelerate. i was told could be my converter locking up a lil
 
Can you make this noise happen sitting still? Will it make the noise at all in Park or Nuetral? If you put the shifter in D and stall it up- rev the engine with foot on brake and not moving- will it make this noise? Without hearing it its hard to say and there are a number of things that it could be. Have you tried to take both belts off of the engine one at a time to see if the noise goes away at all? A bad supercharger coupler will make a lot of racket and a bad balancer will also cause a lot of noise if the rubber in the center breaks.
 


I read that in your first post but you didnt mention if that was sitting stopped and stalling up the torque converter or if you driving down the road at 2000 rpm. Check out the other stuff and let us know if that helps to close in on anything.
 
Flexplate/Torque Converter Vibration Test


To determine and correct a torque converter vibration, the following procedure may have to be performed several times to achieve the best possible torque converter to flywheel balance.
  1. With the engine at idle speed and the transmission in PARK or NEUTRAL, observe the vibration. Turn the engine OFF. Remove the torque converter bolts. Refer to Torque Converter Cover Replacement . Rotate the torque converter one bolt position. Install torque converter bolts. Refer to Torque Converter Cover Replacement .
  2. With the engine at idle speed and the transmission in PARK or NEUTRAL, observe the vibration.
Repeat this procedure until you obtain the best possible balance
 
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