Hi, my 2004 350z MT has this horrible chattering sound when I drive more than 30 minutes, or if I'm idling it makes this weird sound. I replaced the clutch a six months ago and the mechanic said that its normal with Z's to have chatter. Any advice on why its making that sound? I don't really know much about how car's engine, etc. work.

 

Our cars are notorious for having very loud flywheels. That is definitely the sound you are hearing. It is because our cars have a dual mass flywheel and not a single plate flywheel. Leading to more chatter. Hope this helps!

 

Is there anyway to help it not be so loud? Also someone told me you have to replace the flywheel with the clutch and the shop never mentioned this and only replaced the clutch, should I replace the flywheel too?

 

did they resurface the flywheel when they did clutch?

 

Most shops are not going to be able to resurface a DMF , you will want to upgrade to single mass flywheel if you are replacing the clutch.

Chatter is going to happen no matter the flywheel, some more some less.I suggest you search as this has been covered.

 

yeah i am trying to figure out why they didnt replace it since they were already there

 

Yeah, I get flywheel chatter as well. It's pretty annoying at times, but it isn't anything out of the ordinary. THe only thing I've found to stop it is to engage at a little higher RPM. Otherwise, you'll be going *chk*chk*chk*chk*chk* lolol

 

Yes it is very vert annoying. Just turn the music up and don't worry about it.

From my research it doesn't hurt anything, but literally is annoying. Don't get me started on the window motors.. >.<

 

Regards, idgaf: A dual mass flywheel (DMF) is composed of two rotating masses, a primary mass bolted to the crank, and a secondary mass which engages the clutch disc and is positioned relative to the primary mass with a bearing. In the 350Z, this bearing is housed in a nylon bushing. These elements are dampened with heavy springs placed radially between the two.

View:
The purpose is to isolate the drive train from engine pulses, to cushion the transfer of torque between the crank and transmission and, in conjunction with the harmonic balance function associated with the crankshaft pulley, to provide a "tuned" system to stabilize crankshaft whiplash and, as each cylinder fires, pulsation. V-6 engines are well known for a lack of refinement in this regard.

DMFs wear both longitudinally (float) and axially (rock or tilt). Longitudinal wear may be evident in poor coupling (slipping) of the clutch, rock results in imbalance and consequent vibration which MAY produce eccentric rotation of the transmission input shaft causing bearing damage (the famous gravel in a can noise) and starter problems.

Wear is accelerated under shock (dumping the clutch) or heavy loads (WOT), and under extreme duty may show signs of failure in a surprisingly short time. Most DMFs are expected to last through two clutch changes but there is, relative to usage, no guarantee one will last this long.

A severely worn DMF:
Single mass flywheels were OEM until about 1985 when the DMF was designed to cushion the exaggerated low rpm pulsations of the four piston diesel engines which were becoming popular at that time, DMFs have since found their way into performance engines and are now common in all performance/duty ranges.

There is no downside to replacing a DMF with a solid, or single mass flywheel if chosen correctly for its intended application. An extremely lightweight flywheel will reduce rotational mass resulting in faster acceleration, particularly in the lower gears where it has been calculated that in first gear a reduction of one lb results in an effective (not actual) 3hp increase. A lightening of the flywheel by 10 lbs is equivalent to a 30 hp improvement---IN FIRST GEAR--- (this performance increase may not be evident in higher gears, 5th or 6th). Extremely light flywheels might be selected for an engine intended for the drags or other events where acceleration in low gear ranges is important but as there is less mass to absorb vibration or damp noise, these factors will be more noticeable.

The downside (there's always a complication) is that etremely low mass solid flywheels are not "tuned" to relieve crankshaft whiplash, and, at the other end, will transfer sudden torque to the tranny resulting in damage to bearings, synchronizers (rpm matching), this is also likely to eventually cause gear lash, accelerated wear to main bearings and failure of the rear seal.

For a daily driver, a heavier SMF will work well, as this system has for the previous one hundred years. It's important however to ensure the clutch disc is spring loaded as some degree of relief, or cushioning, in the transference of energy from engine to drive train is desirable.

 

Also when I let the clutch out it makes this sound... this isnt my video but it sounds exactly like this...


It started after I got the clutch replaced

 

just flywheel chatter... what clutch did you get? factory flywheel still?

 

The sound in post #10 is quite normal, although that one may be a little louder than normal.
I'm pretty sure it's the clutch fork and TOB wiggling around inside the housing.

 

My fly wheel chatters like a bunch of nuns in a sex toy factory. I can't imagine a aftermarket one. I psyched myself out into thinking something was wrong when I first noticed it in a drive through.

 

So its normal and nothing to worry about? Sorry I'm not very car savvy lol.

 

I got the Excedy kit

 

If it operates smoothly and does it's job, then everything is fine

The noise does go away when you push the pedal, right?

It sounds louder after the car warms up because your idle has come down and it seems to chatter more at lower rpms......Right?

 

yes when I push the clutch in, the noise goes away. The chatter (while driving) is louder at lower rpms and really loud if I don't downshift when if I make a turn in 3rd or something ( I almost always downshift tho it was just once or twice)

 

I wouldn't worry unless it gets worse.

 

Okay thanks