Calling all strange noise experts - What is this sound? (not a bearing thread)

[Emm Tree]

All,

Let me start by saying that I've heard this noise on other cars of varying makes and models, so it's not e9x M3 specific. However, it has gotten progressively worse over the last 6 months and it doesn't sound very "M" so it needs to go away. At least this isn't another "bearing thread."

The sound is a chatter. My car is a 2011.5 with a DCT.

What I know:
1. It occurs after the car has been warm for a 20 minutes or so.
2. It only happens when the car is in gear, under load, and somewhere between 1500-3000 rpm.
3. As stated above, in neutral, this sound does not occur.
4. I first noticed the sound when switching into reverse or climbing inclines into parking structures. Now I can hear the sound under load on the freeway.
5. I can feel lateral vibrations in the steering wheel that I believe correlate with the sound. This is new, and troubling.

My best guesses:
1. Driveshaft play.
2. Loose belt.
3. Busted engine mount.
4. Flex plate chatter.

I finally capture the sound on video. Happy hunting! *fingers crossed for something inexpensive and insignificant*

[Emm Tree]

Video.

[IIAp3x]

Originally Posted by Emm Tree

All,

Let me start by saying that I've heard this noise on other cars of varying makes and models, so it's not e9x M3 specific. However, it has gotten progressively worse over the last 6 months and it doesn't sound very "M" so it needs to go away. At least this isn't another "bearing thread."

The sound is a chatter. My car is a 2011.5 with a DCT.

What I know:
1. It occurs after the car has been warm for a 20 minutes or so.
2. It only happens when the car is in gear, under load, and somewhere between 1500-3000 rpm.
3. As stated above, in neutral, this sound does not occur.
4. I first noticed the sound when switching into reverse or climbing inclines into parking structures. Now I can hear the sound under load on the freeway.
5. I can feel lateral vibrations in the steering wheel that I believe correlate with the sound. This is new, and troubling.

My best guesses:
1. Driveshaft play.
2. Loose belt.
3. Busted engine mount.
4. Flex plate chatter.

I finally capture the sound on video. Happy hunting! *fingers crossed for something inexpensive and insignificant*

Mileage?

[Emm Tree]

Originally Posted by IIAp3x

Mileage?

56k.

[vsix]

Hmmm...it has a an slight metallic rattle to it. I even here a little bit of clutch chatter...
can we get a longer vid?

[Emm Tree]

Originally Posted by vsix

Hmmm...it has a an slight metallic rattle to it. I even here a little bit of clutch chatter...
can we get a longer vid?

My first thought was clutch chatter. But that wouldn't explain why I can hear it at cruising speed on the freeway under load. 4th gear at 2500 is where it's most pronounced.

Longer video added above.

[vsix]

Originally Posted by Emm Tree

My first thought was clutch chatter. But that wouldn't explain why I can hear it at cruising speed on the freeway under load. 4th gear at 2500 is where it's most pronounced.

Longer video added above.

I would rule out the driveshaft, as you don't feel it through your steering wheel.
It is something that definately has play and engine mounts on slight acceleration do not chatter like that.
Give me some time to think about it and maybe get a short clip from the inside, drivers side compartment?
Thanx.

[Emm Tree]

Originally Posted by vsix

I would rule out the driveshaft, as you don't feel it through your steering wheel.
It is something that definately has play and engine mounts on slight acceleration do not chatter like that.
Give me some time to think about it and maybe get a short clip from the inside, drivers side compartment?
Thanx.

Appreciate it. I agree, something definitely has play. You can't hear much from inside the car (either because Akra Evo or because sound deadening). I'll try to get one on my morning commute.

It's possible that the lateral vibrations aren't related to the sound and are something that I've incorrectly related. It's possible, but I'm pretty tuned in.

Keep in mind - I've heard this sound come from other cars (E350s, Taurus, MX3s alike). Same sound, same tone, same circumstance (accelerating from a stop). There's got to be a commonality.

[vsix]

Ok, when I can rely on your statement, that this chatter sound only occurs, when in gear and under load, I can definately only point out 2 relevant factors, wich would be:
engine or driveline related.
Now the thing is...where does that sound come's from?
Front, middle or rear of the car?
As for now:
It almost sounds as it could be something vibrating that isn't rotating, like an heat shield somewhere underneath the car?

You know? You can do alot of supporting actions, like take a picture from underneath the car. That way, we might be in the position to help you, as we would see if something would look off in a way.
Did you had any codes recently?

[Emm Tree]

Originally Posted by vsix

Ok, when I can rely on your statement, that this chatter sound only occurs, when in gear and under load, I can definately only point out 2 relevant factors, wich would be:
engine or driveline related.
Now the thing is...where does that sound come's from?
Front, middle or rear of the car?
As for now:
It almost sounds as it could be something vibrating that isn't rotating, like an heat shield somewhere underneath the car?

You know? You can do alot of supporting actions, like take a picture from underneath the car. That way, we might be in the position to help you, as we would see if something would look off in a way.
Did you had any codes recently?

It very well could be something non-rotational, like a heat shield. The fact that it's getting worse making me think something it loosening over time.

As for where the sound is coming from, it sound like it's coming from the bottom middle of the engine bay. From inside the cabin, it sounds like it's coming from somewhere between the engine and the space between the driver and passenger footwell.

As for codes, everything is clean and clear.

Unfortunately, I won't be able to get pictures of the underbelly of the car.

I guess I can take it as a good sign that we didn't diagnosed the problem instantaneously. Good that it's not a major, known issue; bad that it could be anything rattling loose.

Could this be a simple blown engine mount? That would make sense to me given the symptoms (and the knowledge that my engine mount(s) hasn't been changed yet).

[bimmerfrk]

hmm sounds like you bearings are about to go.... I feel for you op.

[IIAp3x]

Put on swing arm lift and drive it in gear with the wheels off the ground, and have someone else isolate the area of noise from underneath... There are just too many possible things it could be; not to mention that the steering vibration may not be related...

You can try on jackstands, but I would not recommend it if avoidable...

I am thinking of several things-
-driveshaft joint
-clutch chatter
-motor mounts
-trans mounts
-exhaust shield
-exhaust

[Emm Tree]

Originally Posted by bimmerfrk

hmm sounds like you bearings are about to go.... I feel for you op.

Definitely not bearings. You can't scare me.

[Emm Tree]

Originally Posted by IIAp3x

Put on swing arm lift and drive it in gear with the wheels off the ground, and have someone else isolate the area of noise from underneath... There are just too many possible things it could be; not to mention that the steering vibration may not be related...

You can try on jackstands, but I would not recommend it if avoidable...

I am thinking of several things-
-driveshaft joint
-clutch chatter
-motor mounts
-trans mounts

Good points. Transmission mounts are something I haven't considered.

I like your idea re: putting the car in drive while suspended. It's worth a try. However, I'm concerned the sound only occurs when the engine is torquing something as the motor is perfect while in neutral.

This is shaping up to mean a trip to Malek at MRF.

[kb9uwu]

Originally Posted by vsix

I would rule out the driveshaft, as you don't feel it through your steering wheel.

Why would you feel driveshaft vibrations through the steering wheel?

[Emm Tree]

Originally Posted by kb9uwu

Why would you feel driveshaft vibrations through the steering wheel?

The steering wheel vibrations might be a figment of my imagination.

Driveshaft play was my first thought as it makes the most sense and the sound comes from where I imagine the driveshaft was chatter under load.

But driveshaft chatter is fairly common and the noise my car is making is pretty distinct. I expected someone would have called it right away if it was the driveshaft.

[vsix]

Originally Posted by Emm Tree

The steering wheel vibrations might be a figment of my imagination.

Driveshaft play was my first thought as it makes the most sense and the sound comes from where I imagine the driveshaft was chatter under load.

But driveshaft chatter is fairly common and the noise my car is making is pretty distinct. I expected someone would have called it right away if it was the driveshaft.

Your driveshaft would vibrate through your whole car at a certain Speed but is unrecognizable on slower speeds. No steering vibration at all and my driveshaft was shot to nirvana. ( squeeked )
My car was developing bad vibrations around 180km/h. Funny cooncidence I replaced mine today and the vibration I was getting are now completely gone

[IIAp3x]

Originally Posted by Emm Tree

The steering wheel vibrations might be a figment of my imagination.

Driveshaft play was my first thought as it makes the most sense and the sound comes from where I imagine the driveshaft was chatter under load.

But driveshaft chatter is fairly common and the noise my car is making is pretty distinct. I expected someone would have called it right away if it was the driveshaft.

Although with such low mileage I would think that your driveshaft is good, unless your doing a lot of burnouts or abusing the car with excessive launches... Even then I would think that the differential gears would go first before the driveshaft... It's pretty damn solid...

[IIAp3x]

Originally Posted by kb9uwu

Why would you feel driveshaft vibrations through the steering wheel?

He had mentioned that he was not sure that they were related...

[IIAp3x]

Originally Posted by Emm Tree

Good points. Transmission mounts are something I haven't considered.

I like your idea re: putting the car in drive while suspended. It's worth a try. However, I'm concerned the sound only occurs when the engine is torquing something as the motor is perfect while in neutral.

This is shaping up to mean a trip to Malek at MRF.

Yeah I think this would call for someone with a decent lift... Hopefully it's nothing serious... Keep us posted!

[Sweetchuck]

Heat shields. Inexpensive and insignificant.

[Emm Tree]

Originally Posted by vsix

Ok

Originally Posted by IIAp3x

Mileage?

Could this be engine knock? A loose belt tensioner?

I should have probably mentioned that, among other things, my car has MS Pulleys, Akra Evo, and an Evolve tune.