Flywheel Rattle?

[fistpoint]

I think it's time for a "DI" meme...since every odd sound with this car is now being associated with the DI system.

What happened to the great NVH(noise, vibration, harshness) theme car companies had going for it back in the 90's? That used to be a priority.

[CB762]

I'm not very mechanically inclined and following could be wrong but: this car has lightweight flywheel and those are prone to rattle at idle. On the other hand, they usually rattle continuously, not just for few seconds.
I will take the car to dealer but I'm afraid they are not very experienced with FR-S yet.

[Hanzo]

My 2002 WRX had that and my BRZ have it so I figured it's normal for Subaru.

[sparks]

Originally Posted by 3essess

First off, love the way the car drives except for this one "grinding" or "rattling - gear grinding type" sound that happens exactly as you described and in your vid.
It sort of sound like the sound made when you're trying to put your car into gear without using the clutch. After driving for over 1000 miles, I can usually make this sound happen under the following conditions:

1) When slowing down for a stop or turn, put your car into neutral - so your coasting down.

2) When slowing down in neutral, the revs will usually settle in around 1000 rpm or so until you get down to below 25mph or slower. Then the revs will finally settle in to 700 or so...then the revs will bounce down lower to 550 to or 650 rpm and that is when I hear the rattling sound.

3) Like you, I also can make the rattling stop if I push in the clutch, or, if I bring the revs up via the throttle - the sound goes away. Or, if I do nothing, it will slowly stop in about 2 or 3 or 4 seconds - once the engine revs recovers.

4) No matter how hard I try to duplicate the sound with the car NOT moving, it will not happen. The car needs to be moving in neutral to make the sound come out.

5) To me, it sounds like something in the transmission is rattling, whether gears or rods or whatever. Could it be the motor knocking at that low rpm - I hope not.

We gotta get this resolved...

Thanks.

Perfect descrition of when the rattle happens. I've sent the video and your explination to our Subaru Field Service Engineer (FSM).

UPDATE - SOA FSM will be here Tuesday to investigate my issue.

[F1point4]

My FR-S does the exact same thing. I took it in 6/19. Scion N/A calls me every 2 days but they don't have updates. Nice gesture though.
http://www.ft86club.com/forums/showp...8&postcount=18

Originally Posted by F1point4

Took my car to the dealership today. Demanded that I be present in the car when the tech takes it for a test drive. To my surprise I ended up driving the technician and repeatedly demonstrating the issue to him. He acknowledged the existence of the noise but wasn't sure what the issue was so he got the foreman involved.

I asked this technician about the high pitch chirping and he is fairly sure it is the Direct Injection system.

After a few calls to Gulf States Toyota (I think this is a regional distributor) and California, they still weren't sure what the noise was. Gulf States said they wanted the Foreman to bring the car over to listen to it. After the foreman and I went for another drive to get synced up on issue and noise in question, I hesitantly agreed to let him bring it over there. Overall I think they will put 80+ miles on the car before I get it back

Just got an update, they had another FR-S to compare it to. In the other vehicle they got the same noise to occur, but it happened much more quietly. They said you really had to listen for the noise. In my car it was much more pronounced. Ultimately they are convinced it was something in my transmission, heard something along the lines of "harmonic balancer". They recorded video, documented the issue and sent it to engineers in California. They deemed the car safe to drive and said there isn't an impact on reliability so I'm getting the car back tomorrow. They aren't sure but they are researching the issue.

I'll continue to touch base with them and get updates. They told me if anything had to be done it'll be covered under warranty.







For anyone who wants to hear this flutter engine noise I'm hearing you can do it two ways. Get the car warmed up first. Roll up your windows. Turn off the radio. Now either

1) get the car up to around 50mph in 5th or 6th gear. When its safe, put it in neutral and brake all the way to 0 with regular pressure like you are doing a normal stop. For me, right around 20mph you'll see the RPM dip and the engine make the flutter/sputter noise.

2) Get the car up to speed, around 45mph. When its safe, put it in neutral and let the car coast and slow down on its own. The Foreman was able to repeatedly hear the sound when it passed 36-38mph.

[Razz]

That doesn't sound like a rattle to me.
It's coming directly from the engine.
I agree, sounds like DI

[Sigh-on-Rice]

Direct Injection noise = "normal" noise.
Toyota's warranty specifically says it does not cover "normal" noise.
People would be wasting their time trying to get Toyota to get rid of this noise.

[CB762]

I noticed very quite chatter (or rattle) coming from engine at idle and it's continuous. That sounds like what others describe as DI.
Also, there is at least 10 times louder rattling lasting just for only 2-3 seconds, under conditions described in the original post, as well as by others.
I took the car to empty stretch of road for about 30 minutes and here my observations about latter:
- rattling occurs practically at any speed after some (even light) acceleration.
- occurs only at idle with clutch engaged (pedal depressed).
- unable to reproduce while in gear or with clutch pedal in.
- sounds and feels like vibration of rotating mass.

Have scheduled an appointment with dealership on thursday but I doubt they will be able to come to a conclusion.

[Lee358]

drove an FR-S today heard the exact same sound

[3essess]

Originally Posted by CB762

I noticed very quite chatter (or rattle) coming from engine at idle and it's continuous. That sounds like what others describe as DI.
Also, there is at least 10 times louder rattling lasting just for only 2-3 seconds, under conditions described in the original post, as well as by others.

CONCUR...I also hear the DI and that sound comes and goes and will last for MUCH longer than the rattle we're talking about.

The rattle we're describing is WAY louder than the DI clatter and you can really hear it with the windows rolled up and the stereo off while slowing down in neutral. I understand and can also hear the DI under the same circumstances, however, that sound is distant and muted. The one I hear sounds about as loud as the switch in the engine that turns the AC on and off...

Thanks all.

[ExoticAir]

all normal.

[JDM_Badge]

I am going with DI or more likely a harmonic vibration somewhere. All 3 of the FR-S's I have driven do this at idle from time to time. I am guessing it is normal. Every car has a harmless quirk or two, I am sure this is one of ours. You might report it to the dealer as a concern if you are worried something is going wrong, just for documentations sake so they cannot say you ignored it.. but I am pretty darn sure you have nothing to worry about. They told me it was something they all did when I test drove it, warning me in advance, at TWO separate dealers in different states. Their mechanics noticed first and looked into it on their first PDIs.

[sparks]

Originally Posted by sparks

Perfect descrition of when the rattle happens. I've sent the video and your explination to our Subaru Field Service Engineer (FSM).

UPDATE - SOA FSM will be here Tuesday to investigate my issue.

The FSM just finished data logging my car. I was able to re-create the rattle 10 times during the log. He noticed it happens when the RPMs drop below 600. He is sending the log to SOA engineering for evaluation.

[3essess]

Originally Posted by sparks

The FSM just finished data logging my car. I was able to re-create the rattle 10 times during the log. He noticed it happens when the RPMs drop below 600. He is sending the log to SOA engineering for evaluation.

Thanks and appreciate the update man. I've been recently driving around the issue by keeping my car in gear till almost a complete stop. Nonetheless, sound came out again this morning while slowing down,and exactly as you said, rattle came out when revs dipped rolling in neutral.