Flywheel Rattle?

[Itzed]

Just noticed this on my car after 14K. Glad I found this thread and know I'm not alone now. Before I read any of this, I was hypothesizing it was the FI switching over from direct injection to port injection.

[hmong337]

Anybody actually pin point absolutely what causes this noise and not just guessing...?

My car has done this since day one.

....getting off the highway, throw it in neutral to coast, "chappa chappa chappa"....

Never owned a car that did this before. It's doesn't happen all the time but it does happen from time to time. My guess is a loose throw out bearing rattling around.

[steve99]

-@

Originally Posted by hmong337

Anybody actually pin point absolutely what causes this noise and not just guessing...?

My car has done this since day one.

....getting off the highway, throw it in neutral to coast, "chappa chappa chappa"....

Never owned a car that did this before. It's doesn't happen all the time but it does happen from time to time. My guess is a loose throw out bearing rattling around.

mine used to do similar and when coasting to a stop and occasional dip with a\c on in summer. zeroed out the port\direct intection ratio tables up to 0.3 engine load as per tune tweaks thread below and not noticed it since. i think it gear backlash as the engine nearly stall the ecu catches it. by running full direct intection at idle and rearly low load ecu appears to be able to catch the dip quicker and its not trying to inject minute amounts of fuel via both injection systems and no noise , smoother idle and takeoff

standard setting is about 30\60, port\direct

[ZZT86]

Always thought the rattle was caused by low engine revs vibration which rattles clutch components even when in gear. Shitty sound but always thought it normal.

[axelo]

Originally Posted by ZZT86

Always thought the rattle was caused by low engine revs vibration which rattles clutch components even when in gear. Shitty sound but always thought it normal.

That happened to me since out of the dealer until headers, overpipe, front pipe, catback and tune (ecutek)...dont ask me why it stopped doing it...i'll ask my tuner !?!?

Car haves always been running good since out of dealer anyways...even with that rattle i dont miss at all

So dont worry!! My 2cents! Hope it helps calm your worry

Sent from my SGH-I337M using Tapatalk

[Da Brz]

I'll bump this old thread because I've been watching my RPMs while this happens to see if the noise is tied to the engine speed or the car's speed when coming to a stop.


What I've noticed is that with the clutch out and in neutral, when coming to a stop the engine RPMs will drop down to about 500rpm and that's when you hear the rattle/knocking sound. Then the rpms shoot back up.


This sounds and looks a lot like the idle fluctuation problem my car has. Idle drops to 500rpm, engine knocks/tries to stall, then shoots back up.


I think when slowing down in neutral, for some reason the engine just wants to drop too much too fast.


Essentially, I don't think the rattle sound is the flywheel, I think it's the engine almost stalling due to dropping to too low of an RPM.


Why it doesn't do this with the clutch in and the car in gear is beyond me.

[TelMinz]

Originally Posted by Da Brz

I'll bump this old thread because I've been watching my RPMs while this happens to see if the noise is tied to the engine speed or the car's speed when coming to a stop.


What I've noticed is that with the clutch out and in neutral, when coming to a stop the engine RPMs will drop down to about 500rpm and that's when you hear the rattle/knocking sound. Then the rpms shoot back up.


This sounds and looks a lot like the idle fluctuation problem my car has. Idle drops to 500rpm, engine knocks/tries to stall, then shoots back up.


I think when slowing down in neutral, for some reason the engine just wants to drop too much too fast.


Essentially, I don't think the rattle sound is the flywheel, I think it's the engine almost stalling due to dropping to too low of an RPM.


Why it doesn't do this with the clutch in and the car in gear is beyond me.

Could be the throw out bearing, mine did this as well. Gave up the ghost at about 95k miles, bearing separated from the plastic sleeve, idk how long it was like that, but after I put in a new throw out bearing the rattle is gone.

[Ultramaroon]

To answer the bump, this is normal. It is not the flywheel. At low RPM the firing pulses of the engine rattle the freewheeling gears in the transmission.

Same thing when lugging the engine. All the gears are always spinning. Only one pair at a time is engaged with the output shaft. The rest of them jiggle around in there.