"Rattling" Noise when letting off the clutch

[Ben W]

Hello! I am new to these Forums, but I have been "working" on my 99 Eclipse and I figured this would be a great place for assistance, tips, and other support. I put working in quotation marks as I got the car as is, with all the upgrades already installed, and have been not so much putting things in, so much as making sure what is already in is functioning properly. (The reason the guy I bought it from sold it, was it wasn't quite running right and ran out of money)

PS- this is my first car, so I'm kinda learning the basics with it too

Anyways, my current issue

I have started noticing a noise when letting off the clutch while driving. Its hard to describe noises in words but ill do my best
It is kinda sorta a rattling noise

The image that runs through my head when I hear the noise, is a metal plate/disc with a pole running through the center that is vibrating on it and makes noise as it gets pressed from both ends

I notice the noise the MOST when I shift poorly (when I don't quite match the rpms) and I don't hear it at all when I do a good, smooth shift.
I tried going in and out of gear with the car off to see if I could hear any noise at all, but that didn't produce anything.
There is no noise while IN gear, or OUT of gear. Though I believe I do sometimes hear the noise when pressing the clutch in as well, at the point of when the transmission actually disengages

There is no affect on drivability, and I don't FEEL anything when this occurs. Ive been driving the car for about a year and a half. The car has almost 170,000mi on it, but the engine, transmission, and multiple other parts were completely swapped at about 160,000mi. Most issues SO FAR have been the stock pieces giving out (wiring and etc).

Thanks in advance!

 

[Kryndon]

Hi and welcome! This place is wonderful and full of info, so make sure you visit and read as often as possible.

Initially what comes to my mind is a clutch release bearing (TOB). You said you don't "feel" anything, but are there any vibrations when pressing or depressing the clutch pedal throughout its movement?

Two other things that I can think of are transmission main shaft bearing, or the center carrier bearing for your driveshaft (if yours is an AWD, you haven't specified).

 

[Ben W]

Hi and welcome! This place is wonderful and full of info, so make sure you visit and read as often as possible.

Initially what comes to my mind is a clutch release bearing (TOB). You said you don't "feel" anything, but are there any vibrations when pressing or depressing the clutch pedal throughout its movement?

Two other things that I can think of are transmission main shaft bearing, or the center carrier bearing for your driveshaft (if yours is an AWD, you haven't specified).

Thanks for the quick response!
My car is FWD.

When I shift poorly the car vibrates as the transmission is engaging, but I believe that's normal for manuals due to mismatched rpms, yes? Its been like that from the start.

 

[1990TSIAWDTALON]

Bad syncro's in the transmission if you have to rpm match to shift. That is their job, to match the speed of the gear set.

 

[Mischif]

Sounds like either loose/worn springs in your clutch disc, or a bad throw out bearing. I'd lean toward it being springs since you say you get vibrations when you shift poorly.

 

[2gGst98]

Do you know the maintenance history?

Where the Motor mounts changed with new motor? Is there poly inserts (red bushings that slide into front and rear mount). Would put 20 bucks on new front and rear motor mounts fixing the vibrating issue.

For the rattling I'll put another 20 bucks on the TOB. Especially if proper maintenance has not been done. Just because he said at 160k motor and trans where changed. Doesn't mean they where new, but they could be new with all the old parts.

 

[Ben W]

Do you know the maintenance history?

Where the Motor mounts changed with new motor? Is there poly inserts (red bushings that slide into front and rear mount). Would put 20 bucks on new front and rear motor mounts fixing the vibrating issue.

For the rattling I'll put another 20 bucks on the TOB. Especially if proper maintenance has not been done. Just because he said at 160k motor and trans where changed. Doesn't mean they where new, but they could be new with all the old parts.

TOB? I need to learn the car lingo haha

And just to clarify to make sure I'm not stupid, when people say "motor mounts" that is the same as engine mounts, yes?
I had the engine mounts checked and tightened due to another issue that is popping up

I took the car into the dealership for a basic timing belt replacement, as mine got a hole in it. Anyway, I mentioned the issue to their mechanic, and he said its normal for aftermarket parts to make noise. However, I know for a fact I didn't hear this rattling for the first 1 and a half ive been driving it.

 

[2gGst98]

TOB - Throw out bearing.

I am not calling you stupid bud, everyone had no idea at one point. You ask questions and want to learn we will help you.

google a question and put DSM after it, this website will pop up with info about your question. This is for just about any question you can think of.

 

[teamevolution2]

My first bet with noise in the tranny would be TOB. as 1990TSIAWDTALON you also shouldnt have to revmatch to have a smooth shift.

 

[chrysler kid]

It is fairly normal for an aftermarket non oem throw out bearing to make noise. It is also normal for a loose bolt, or an entire battery hold down bracket to get lost under the battery by the subframe and rattle whenever the transmission moves.

Damn engine cradle eats everything that gets dropped in the bay. I swear that's where you'll find half the wrenches and sockets that go missing

 

[Ben W]

It is fairly normal for an aftermarket non oem throw out bearing to make noise. It is also normal for a loose bolt, or an entire battery hold down bracket to get lost under the battery by the subframe and rattle whenever the transmission moves.

Damn engine cradle eats everything that gets dropped in the bay. I swear that's where you'll find half the wrenches and sockets that go missing

If only it was so simply. Ill check, but I doubt its anything that easy.

And to the others above, ill google Throw Out Bearing. Hopefully its something that can be done by hand, I'm trying to avoid shops as much as possible to force myself to become technical, and also to save that $$$

Question in regards to shifting and rev matching
With my car, If I don't match revs, it will shift and all, but it sort of shudders a bit when it does it. I assumed that was normal

 

[chrysler kid]

If only it was so simply. Ill check, but I doubt its anything that easy.

And to the others above, ill google Throw Out Bearing. Hopefully its something that can be done by hand, I'm trying to avoid shops as much as possible to force myself to become technical, and also to save that $$$

Question in regards to shifting and rev matching
With my car, If I don't match revs, it will shift and all, but it sort of shudders a bit when it does it. I assumed that was normal

You could have a bad motor mount or transmission mount.

A new clutch will typically have a slight bit of chatter so to speak, but usually only when releasing from a stop.

The throw out bearing is internal to the transmission. To put it simply it's a spinning circle that gets pushed against the pressure plate of the clutch, to remove pressure from the clutch, so the engine spins freely with the clutch pedal pushed down.

A really bad throw out bearing will make noise with the engine in neutral and the pedal up, and stop making noise when the pedal is pushed down against the clutch