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LOUD Knock..Flexplate? Bearing?

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Old Nov 7, 2010 | 08:48 AM
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Default LOUD Knock..Flexplate? Bearing?

So the other day i was driving in town(about 20 miles from my house) and i come to a stop sign and i start to hear a gigantic knock that sounds like something came loose and is rattling around inside my motor.I had no choice but to drive it home.The noise went away above 2800 rpm but still wasn't driving good.I did end up making it home and im preparing for the worst.

Now from what Ive gathered that if it was a bearing the sound would be constant and repetitive.The sound 1 am dealing with is very sporadic and sounds like something is just bouncing around but goes completely away above a certain rpm and is very loud.

But the car is going in sometime this week hopefully and ill find out for sure, but what is the cost difference between a broken flex plate and a rod bearing?..Im sure the bearing is going to be more but is a broken flexplate a semi cheap fix?

Ill try to get a vid up later of my car..
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Old Nov 7, 2010 | 08:55 AM
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A broken or cracked flexplate will sound like a clanking noise,realitivly cheap fix.If its a bearing it will sound like a constant knock that will change with rpm and will not go away.Lots of money.Sounds like you might have a cracked flexplate.
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Old Nov 7, 2010 | 09:04 AM
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Originally Posted by NHRAFORMULA00
A broken or cracked flexplate will sound like a clanking noise,realitivly cheap fix.If its a bearing it will sound like a constant knock that will change with rpm and will not go away.Lots of money.Sounds like you might have a cracked flexplate.
So with a bearing the noise will not go away with rpm change?

Also the car stalls/stumbles out when coming to a stop now,it did sometimes before but i attributed it to tuning.But the noise definitely went away when i was driving home on the interstate.It came back when i slowed down.
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Old Nov 7, 2010 | 09:29 AM
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I just checked the oil in my car and it looks fine...There is no metal flakes of any kind in the oil...looks perfect.
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Old Nov 7, 2010 | 09:51 AM
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Anything related to bearings, typically don't go away at a certain RPM, typically.
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Old Nov 7, 2010 | 11:37 AM
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Thanks for all the help...it should ease my feelings on the issue a little.How much does it typically cost to swap out a flex-plate?
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Old Nov 7, 2010 | 07:23 PM
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Generally your oil pressure will dip significantly with bearing issues

A flexplate is pretty cheap at $0-100 new/used. If you're not doing the work yourself then expect to pay for a trans removal and install @ 5-8hrs

Before you dig in, jack the car up and look under it for something obvious that may have came loose or could cause a bad vibration
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Old Dec 5, 2010 | 10:00 AM
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Well my car is going to sit for awhile(don't have the cash to fix for about a few months)..Is there anything i need to do as far as drain the oil out or crank the car every week or so? I still haven't had it towed anywhere to see what the problem is..I hope its the flex plate.Is there anything else that would have the sound of something bouncing around inside the car.Could i have dropped a lifter or bent a push-rod or anything that you guys can think of.

Ive been really depressed about my car being down,Ive put so much into it and watching it out in my driveway is just KILLING me.My mother-in law just strait out gave me her 04 camry to drive back and forth to work and she went and bough a new ca...which is cool as hell...BUT..I want my car back SO much...Its killing me!!
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Old Dec 5, 2010 | 10:14 AM
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You should pull the small inspection cover on the bottom of the transmission bellhousing and peer inside and see if you can see something obviously wrong.
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