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Car shakes at 25-30 mph... TC problem?

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Old 05-15-2005, 10:44 PM
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Default Car shakes at 25-30 mph... TC problem?

Well my car has been doing this for a little bit now.. i thought it was my shift solenoids but its not.. I just got them changed and it still does it.. It on;y happens when i am coasting or BARELY accelerating.. and it only happens around 25-30 MPH.. The car will start shaking from front to back it seems like.. It does it in Drive and OD.. So theres no difference there.. But i think it has to do with the torque converter locking and unlocking.. because the only way i can keep it front shaking like that is to lightly put my foot on the brake while driving at those speeds.. and when its shaking and i hit the brake it stops right away.. then when i release the brake it will sometimes do it all over again.. these are some possibilities i think..

1. Has to do with custom tuning on shift points or TC lock up?
2. Is my tranny finally starting to show signs of breaking down?
3. My TC crapping out on me somehow?

Car runs fine any other time and even when racing.. only messes up when at those certain speeds..

If anyone can help me.. I'd appreciate it big time! I don't know what it could be! Thanks !!
Old 05-15-2005, 11:36 PM
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Is it a shake or a lunge feeling?

I only get that feeling around lockup speed which is around 35mph. I get no shake but like a soft jolt or lunge.
Old 05-16-2005, 12:08 AM
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Ok.

I just went through a similar problem, only mine did this at 50 mph. If I tried to slowly accelerate from that point, the car just shook like a futhermucker, and didnt go anywhere.. was fine if I mashed the gas pedal at 50, but didn't want to do anything if I feathered the pedal.

It took me a week to find the problem.

Now, this is going to sound completely retarded, I know.

But my problem was one loose spark plug wire. I fixed that, the problem went away. (Wtf?! How does that have any affect on this, I don't know..)

Check your spark plugs. All of them. Even the hard to get one, the furthest one on the passenger side (thats the one that was the culprit in my case).
Old 05-16-2005, 01:30 AM
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Hmm weird
Old 05-16-2005, 11:10 PM
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haha that is crazy.. yea mine is more of a lunge back and forth.. and the crazy thing is mine shutters at 50 mph sometimes.. once in a while... it just shutters once though.. but at 25-30 it does it bad.. and it is definately at lock up speed.. but i had TM removed in my tune.. is it something to do with that? not sure exactly why its doing it.. i guess i could check my plugs and plug wires.. let me know what you think! thanks for the help guys!
Old 05-17-2005, 11:32 AM
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I would like to know as well. My friends car does this also sometimes if im crusing at 50-60 mph. It sputters and even when i mash WOT it just sputters more. I have to slow down to 45 mph and then WOT to get around it. wierd..
Its a 01 and i know new models had TM probs.
Old 05-17-2005, 01:01 PM
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RollinSScamaro,

checked your plugs and wires yet?
Old 05-17-2005, 01:17 PM
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Mine does the same thing, I have just been chalking it up to the cam. I have a stock converter though.. Converter will soon be a 3500+
Old 05-17-2005, 02:52 PM
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Check your fuel trims.

My converter used to lock and unlock extremely fast making a nasty vibration noise, just as some of you have described - under light load only at certain speeds. Once I got the fuel trims correct I didnt have that problem anymore.

I used a MAFT to get my LT's to zero.
Old 05-17-2005, 03:26 PM
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Misfires cause the PCM to unlock the converter
and lock it back up when they go away. If the
misfire is load related (like mixture, weak spark,
etc.) then this can have you cycling in & out of
lock.
Old 05-17-2005, 05:26 PM
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If you are locking the converter at too low of a mph then car will bog like that. A stick car will do the same thing if you try to put it into a high gear at low speed. Raise the lockup to like 50-60 mph depending on mods and see if it continues. You can alos try turning off the misfire table if you already haven't.
Old 05-17-2005, 11:09 PM
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Well i guess all of it can make sense then.. plug wires/plugs or just tuning the lock up speed.. It seems like my plugs are fine.. i have the plug wires on pretty tight.. I am just going to have to check and see if i can get the tuner that tuned my car to adjust the lock up speed to 50-60.. that way it isn't trying to lock up at such a low speed and bog... I appreciate all the ideas and help guys! i'm going to try a few different things and if something works i'll let you guys know what it was.. Thanks again!!
Old 05-17-2005, 11:42 PM
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Originally Posted by RollinSScamaro
Well i guess all of it can make sense then.. plug wires/plugs or just tuning the lock up speed.. It seems like my plugs are fine.. i have the plug wires on pretty tight.. I am just going to have to check and see if i can get the tuner that tuned my car to adjust the lock up speed to 50-60.. that way it isn't trying to lock up at such a low speed and bog... I appreciate all the ideas and help guys! i'm going to try a few different things and if something works i'll let you guys know what it was.. Thanks again!!
it could also be a _bad_ sparkplug and/or wire
not generating enough spark for whatever the reason may be



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