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Clutch Chatter from Stop into 1st Gear

2010ngojo

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Location
Lancaster, PA, USA
#1
Hi guys,

I recent test drove a 2016 model, previous owner had modified some things on the car. Though it was too dark for me to see everything.

Anyways, it has the usual AC blender noise. But something else caught my attention.

Whenever I start to engage the clutch from a stop, there's a very noticeable chattering noise. Clutch chatter? It will stop after the clutch is fully engaged. Yes, I ride the clutch slightly for a smooth start. And it only happens from stop to 1st. Any other shifts, up or down, is fine. Acceleration seems fine as well. The car doesn't seem to hop, or jitter back and forth.

Possible causes?

-Worn/bad motor mounts. Not sure which one.
-Worn/bad clutch.

Common issue or what? Or what other possible issues could it be?

Wanna get myself into the Fiesta scene. Thanks
 


OP
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2010ngojo

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Thread Starter #3
Modded how far? Was it tracked or Beaten on badly?

Sent from my SM-N950U1 using Tapatalk
Mostly aesthetics or sound mods. Like bov and wheels. Possible cold air intake. Most likely beaten. It did have 70k miles on it. But other than the clatter and the AC blender, no other issue stands out.
 


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Location
Metro Detroit
#4
Clutch chatter is rather common for a manual car with some miles on it. The cause is the Drivers motion pattern during clutch engagement, basically everyone lets out a clutch in an individual manner and this causes peaks and valleys to form in the clutch friction surfaces. Good news is that a new driver can wear in the clutch to their individual motion fairly quickly and when that is completed the clutch will smooth out for that new driver. BTW, if you have a family type group where 3 or more drivers are sharing one car that clutch will actually wear in a fashion that keeps the friction pads rather close to a factory original surface. Basically lots of drivers using the same car will "average out" the clutch.

BTW, learned all this from my Father and in the real world sharing a 1970 VW Beetle with my brother and my sister. When all 3 of use were using the car the clutch was smooth for every one. However once we started heading off to college the clutch would wear in to whoever was still at home or whoever got to take the car to school.
 


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Location
Vancouver
#5
Yeah, I got the chattering clutch like you describe on 2014 model; started about 20k miles, now at 50k. It comes and goes but feels more pronounced when the car has been driven for a while, which is why I dont think it's the clutch surface. Car drives fine, so it's just highly annoying. My two theories were either dual mass flywheel springs or like you said, the transmission mounts. Those mounts also got recently diagnosed to have cracks in all of them... I'll give an update if it cured the chatter once they're replaced.
 


kivnul

Senior Member
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Location
Deer Park, WA
#6
My sons 2014 had its original clutch fall apart. The inner ring/gear separated from the rest of the disk allowing it to rotate freely. It had chatter symptoms before it completely let go. I think it is something that used to happen semi frequently with that years clutch. Doctored up a stock image clutch disk to show what I am talking about.

1575991131717.png
 


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2010ngojo

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Thread Starter #7
Of all the manual cars I've driven, with various mileage, ranging up to 150k miles. Only the Fiesta st I drove does this. I find it hard to believe this is 'common' for a manual car.
 


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Bradenton, FL, USA
#8
Of all the manual cars I've driven, with various mileage, ranging up to 150k miles. Only the Fiesta st I drove does this. I find it hard to believe this is 'common' for a manual car.
Our cars are equipped with dual mass flywheels. Premature failure or failure of clutch or slave cylinder results in chattering because the flywheel is also bound to fail. Typically when one replaces the clutch in these cars they also replace the flywheel.
 


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2010ngojo

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Thread Starter #9
Our cars are equipped with dual mass flywheels. Premature failure or failure of clutch or slave cylinder results in chattering because the flywheel is also bound to fail. Typically when one replaces the clutch in these cars they also replace the flywheel.
Clutch didn't feel like it is worn out, doesn't slips or anything. There's is a possibility the clutch hasn't been replaced yet and it's on its way out. But seems okay to me when I was accelerating. Of course, 1st gear acceleration seems slow with little pick up imo.
 


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Location
Vancouver
#10
So I've been driving with new mounts for a few days now and they fixed the issue for me. Chattering is gone now, as far as I can tell. The mounts are all stock and they still feel rather soft. When taking off you can tell the engine is flexing back and forth and sometimes pulsing for a second (which I think translated into full blown chatter before), but the engagement is now much more solid and consistent throughout the drive.

EDIT: Sorry, cant' really say which mount caused it since I replaced all 3... I would imagine the chatter is from RMM and my other NVH was from the other two. I had a chance to inspect the old mounts that got taken out and they didn't look awful at all, but the difference in feel during the drive was remarkable. I guess you can't always tell.
 


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