Idle knocking noise
 

Ive been having this knocking noise occasionally at idle and now lately Ive had some idle issues where the car feels like it wants to stall at a stop. No check engine lights and stock exhaust currently with stock ecu tune.

[ame]http://youtu.be/yQNlADRwSpY[/ame]

[ame]http://youtu.be/kCdP8sJ7oJc[/ame]

Anyone have something similiar or knoe what this is?

Something doesnt sound right. Dealer visit...

That doesn't sound good. Almost like a bad rod bearing. Defo visit the dealer asap.

Also note:

It doesn't occur when the vehicle is in gear with clutch engaged, but the car does have a slightly rough time if you start slowly in first gear. Also doesn't occur when pressing the clutch pedal down.

Mine has been making this noise since it was brand new. It was only noticeable when I tap the gas pedal like in your first video. After the transmission oil change, it got louder and I can hear it even when it's idling. The noise at idle goes away after about 20 mins of driving. Also goes away when the clutch pedal is depressed like you mentioned. I've seen multiple threads about this noise. I wouldn't worry. Mine is louder than yours.

Well, I'll go along with the "something ain't right" crowd.....:sigh:

It could be an exhaust leak

could be something lose in the valve train

could be something is lose in the area of the clutch

Anyways, I'd suggest you get it tended to ....... :)


humfrz

Grab a small section of garden hose and listen at each cylinder, see if the sound is localized to one cylinder or if it maybe is coming from somewhere else. Is it top end or bottom end?

That does not sound good.

That ain't right. ...really ain't right. ...and it's all 4. I can hear that in your first clip. I think it's the trans or clutch.

Now I'm worried. :(

I don't think it's the engine because I hear it on the power stroke of all 4 cylinders. Also, dead giveaway, Kosta says he doesn't hear it when the clutch pedal is depressed which, I will emphasize for the sake of clarity, is when the clutch is disengaged.

We've seen some stock friction disks frag due to poor quality control where they're riveted together. I'm leaning towards this one being on its way out.

When my trans is cold, I do hear a tiny bit of rumble as the power stroke jiggles all the disengaged gears. That's typical and is called "neutral rollover."

If the sound you hear has existed since new and, this is key, has not changed, I wouldn't sweat it.

It hasn't existed since new. I did have the throw out bearing and clutch disc replaced under warranty a couple months ago.

More info:

The idle issue is present even after driving the car for a couple issue, IE the car drops revs when at a light and almost wants to stall but doesn't quite stall. Wondering if this is a separate issue from the knocking, which I didn't hear today.

That is interesting to hear about the recent work. I suspect a correlation and recommend taking it back to where you had the work done. Like @humfrz said, it sounds like something is loose under that bell housing.

A little infonugget. I have my clutch interlock switch defeated so I don't have to press it when starting the engine. If I time disengaging the starter with goosing the throttle just right, I can get the exact same idle knocking sound you have but it lasts only a split second way below 500 RPM. For me it's the gears rattling with each ignition pulse.

I see your tach. It should not be happening at normal idle RPM, at least not with a stock flywheel.

I could see the idle issue being related if, God forbid, your flywheel was actually coming loose. The crankshaft position scale is back there. I don't know. That seems like a real stretch, though.

Tell us about WHY the clutch and TOB were replaced ...... what was the car doing (or not doing) .. ??

Was the pressure plate replaced.. ?? How about the clutch fork .. ??

As far as the idle dance, that's most likely a "tuning" thing.

Yep, ol @Ultramaroon and I "hear" it as a "something under the bell housing thing" .......therefore, ...... it must be so ..... :D


humfrz

Standard squeaky throwout bearing problem. Clutch fork was not replaced but the pressure plate was.

Well, OK.

Like suggested above, I reckon it's time to take it into the dealer and have them take a listen to that noise.

While you're there, might as well have them fix the idle situation.

If they try to tell you that both are "normal" ....... just tell then to contact either @Ultramaroon or humfrz and we will beat cyber knots on their head till they understand ........ :paddle:


humfrz

Whats the calid of the "stock" ecu tune your using if its earlier than B01C/D then you should update it to that

how would one be able to tell?

That opens a can of worms. If one is comfortable with learning how to tinker with their ECU, great, but it's a steep learning curve with some potentially catastrophic pitfalls. Check out the links in Steve's sig.

Yeah, not planning on going that route until I have more mods on the engine/exhaust/etc, just wasn't sure if there was an easy way to tell the calid of the ECU. I know Subaru messes with the flashes from year to year, and that's why the 08-11 STI's blew motors left and right but the 12-14s didn't.

Most obd scan tools or readers will read out the ecu calibration id.

Torque app (free) on android with a $5 blutooth adapter will do it just conect and select adapter status in torque app

Ironically, my bluetooth OBD2 wont pair with my new phone for some reason. I need to buy another one so I can run my torque.

Im pretty sure my stock map is B01C

Ah, I am behind the curve with respect to the available tools. I don't have an android device. When I got this car, I originally went with a tactrix and eventually got on board with a techstream setup, both of which involve quite a learning curve for the casual user. Less so with the techstream.

As always, many thanks, Steve. You are exceedingly patient and generous.

Read twice, buy once!

I saw that you have the TRD intake. There were people saying that it gives a leaner afr and if you install it is a good measure to adjust the ecu. Is this part covered by your guarantee or is your guarantee already over? Do you have other changes?

Ive had the TRD intake on the car for almost 3 years.

Go to your dealer and let us know the result. Good luck!

I thought Kostamojen's issue is neutral rollover. Mine makes the noise when the RPM is at around 650. When the car is warmed up, the engine idles at 600, so it doesn't make the noise. But when the AC compressor is on or engine is not fully warmed up, the RPM stays 650-700 and that's when it makes rattling noise. Also, when the engine is idling at 600 and I tap the gas pedal, it makes the same noise as in Kostamojen's first video. I thought that noise was from when the engine RPM passes through 650-700, it was making that rattling noise for a moment.

Another thing I learned from this forums is this noise gets louder after a transmission oil change. I had throw out bearing and pressure plate replaced a little less than a year ago. I was expecting the noise to get louder because the transmission oil would be changed also. As I expected, it got louder. But I didn't worry about it since I knew that would happen.

Kostamojen mentioned he got throw out bearing and clutch disc replaced a couple months ago. That means the transmission oil was changed a couple months ago. This might be why he didn't notice the noise before, but only noticed it recently.

I hope Kostamojen's issue is nothing, because mine makes the same noise doing the same thing.

Interesting. I just changed my clutch assembly (including throw out bearing) and resurfaced my flywheel and added a new pilot bearing, along with new motul gear oil and I am having this same issue now.. following. I am bringing it to the dealer tomorrow to get the new ecu flash to see if it smooth's things down a bit. Also the noise in my car gets quieter when I turn of the A/C.

Is this the first time the transmission oil was changed?

I hope the best as well. I get the same effect as you mentioned above but it's only momentary. Kosta's is loud and constant.

I swapped mine out with Redline at about 10K miles. It's a tad noisier but nothing like that. Is it possible the oil level is low? I'm reaching.

Did you ever figure this out?

Any luck?

Could it be another vacuum pump failure like this guy?

http://www.ft86club.com/forums/showthread.php?t=107577

Have you figured what was causing the issue? I had clutch and tob replaced and 2 months after it started knocking in the same manner as in the video. Thanks!

No one has any updates on that? It will be great to hear for a fix. Thanks!