Engine emits rattling noise between 2k to 3k rpm

jagman wrote

Is there a way to fix the intake rattle without going back to the old filter? I removed the one that came with my 08 M3 (I got othe car second hand) and put in a Stage 2 AFE filter and arm. Around the same time I went catless and resonatorless so the sound is on steroids.

I don't believe so. These high flow filters are exaggerating the natural resonance this engine has at those speeds.

I have this noise too and was worried about it, specifically mine also appears at 2500 -3000 rpm under light load in 3rd gear (but not in 1st or 2nd). In 4th gear (or higher gears) road noise and air aerodynamic noise may be covering it as i cannot hear it and it is slight in third gear.

It seems there is a moderate consensus that it's just resonance from/through the air intake or natural resonance from the engine with the air filter. It would be nice if someone could post an audio file of it.

I will try if i get a chance.

Hi guys,

Is this the mechanical fluttering sound everyone is experiencing (link below) Does anyone have a solution for this issue?

It sounds a bit more sinister than air flow resonance. Sounds metallic imo...

The fluttering sounds seems to be less sIgnificant when using a higher octane fuel. Would this mean engine knocking at lower octane fuel?

Cwleo wrote

Hi guys,

Is this the mechanical fluttering sound everyone is experiencing (link below) Does anyone have a solution for this issue?

I have the exact same sound and it is definitely not air intake sound as we all know intake sounds beautiful. I first took my car to a several local BMW independent shops. But one thought it was engine knocking and other could not identify. So I ended up dropping it off at Southbay BMW. I just got a call from them and they weren't able to find any issues with the car and telling me it's normal sound... I just cannot agree with them as it is metal chirping sound almost like something is very loose...anyways, I hope someone can identify this sound. At this point, I'm just glad it's not engine knocking, but would like to know what it is.

kooolaid wrote

I have the exact same sound and it is definitely not air intake sound as we all know intake sounds beautiful. I first took my car to a several local BMW independent shops. But one thought it was engine knocking and other could not identify. So I ended up dropping it off at Southbay BMW. I just got a call from them and they weren't able to find any issues with the car and telling me it's normal sound... I just cannot agree with them as it is metal chirping sound almost like something is very loose...anyways, I hope someone can identify this sound. At this point, I'm just glad it's not engine knocking, but would like to know what it is.

Chill my friend,
Lots of people have this noise. most of them think it is airintake, But some times this noise will gone. One time, I am almost out of gasoline, this noise is gone, and today, I put my Stock Xpipe back, this noise is gone too.(I had ran a MS catless xpipe)

Cwleo wrote

Hi guys,

Is this the mechanical fluttering sound everyone is experiencing (link below) Does anyone have a solution for this issue?

Hey mate,

I am getting the exact same pinging noise, rattling and intermittent tick.
The pinging noise has come on in the last 2000km and the ticking and rattling noises have ONLY come on since my change from TWS to LiquiMoly.
The LM has made my engine a heck of a lot mechanically louder and produced an intermittent tick that wasn't there before (This is identical -)

The suggestion from my mechanic was to swap the rod bearings ASAP. So once I can get a hold of some BE shells and studs it will come out of the garage again.
I'll let you know if it resolves the noises.

Craig

Cwleo wrote

Hi guys,

Is this the mechanical fluttering sound everyone is experiencing (link below) Does anyone have a solution for this issue?

anyone figure out this noise?

Hey mate,

I am intermittently getting the same sound.
Apparently a potential cause is the low pressure fuel sensor playing up.
I have that and other issues like running rich, really rough starts. I have a LPS on order, if it fixes the issue I'll let you know.

Craig

Same rattling issue here in my car and inside the car it almost sounds like the exhaust is rattling.

SouthernBM kept the car for a couple of days but couldn't find a problem. It's heading in tomorrow for it's 50k service and I'll get them to check it again. Thanks to the poster of the vid, super helpful!

Shift down and drive faster, keep the rpm above 3k guys.

All is well all is good

Longwong wrote

Part is a rattle but also I have logged data and if you are in too high of a gear and bogging the engine the knock control system is going wild as given this engine, if rpms are too low and you are in a high gear you are loading the system and the engine will knock unless the knock control starts working overtime so not sure if its a combination of dialed back combustion as it shows on the logging data.

Hi, i think i may have similar issue in 1000-2000 rpm. Happens in gear 2-6. Not something major and can definitely be avoided by driving in manual mode. Can be reduced by setting higher d level. However if the dct is late to shift down it will happen.

Happens when we suddenly mash down the pedal to accelerate. But not in 1 gear which will be an issue if it does

By any chance you know how to fix this?

Picked up my car yesterday from SouthernBM who took a good look at the problem. They upgraded the DME software to the latest version (my car is a 2013, no tune) and I'm now driving a rattle-free car.

FYI, my car sounded just like the video posted above previously.

solistics wrote  

Picked up my car yesterday from SouthernBM who took a good look at the problem. They upgraded the DME software to the latest version (my car is a 2013, no tune) and I'm now driving a rattle-free car.

FYI, my car sounded just like the video posted above previously.

I also have a 2013. What version is the new software? Did the dealer say what the benefits of upgrading are?

Cwleo wrote

Hi guys,

Is this the mechanical fluttering sound everyone is experiencing (link below) Does anyone have a solution for this issue?

So any definitive answer other then airbox and normal sounds? I hear it on my car with the AA supercharger and obviously their DME tune.

AznSupraTT wrote

So any definitive answer other then airbox and normal sounds? I hear it on my car with the AA supercharger and obviously their DME tune.

I hate to pour gasoline onto the bonfire that is rod bearing hysteria, but my car had the exact same 'knocking' noise is the video quoted above. It could be reproduced 100% of the time by accelerating hard from 2nd or 3rd gear with the engine off-idle (aka bog the engine). the knock/ping sound would start at around 2800rpm and disappear by 3500 rpm. It first happened in September during a trip to San Francisco. I thought it was the crappy CA 91 octane gas. When i arrived home in Seattle i filled up with my normal Shell 92, but the sounds persisted. After several bad Blackstone labs reports, I had my rod bearings replaced last week and since then ( last week ) i have not been able to reproduce the noise since.. strange, eh?

Peertwelve wrote

I hate to pour gasoline onto the bonfire that is rod bearing hysteria, but my car had the exact same 'knocking' noise is the video quoted above. It could be reproduced 100% of the time by accelerating hard from 2nd or 3rd gear with the engine off-idle (aka bog the engine). the knock/ping sound would start at around 2800rpm and disappear by 3500 rpm. It first happened in September during a trip to San Francisco. I thought it was the crappy CA 91 octane gas. When i arrived home in Seattle i filled up with my normal Shell 92, but the sounds persisted. After several bad Blackstone labs reports, I had my rod bearings replaced last week and since then ( last week ) i have not been able to reproduce the noise since.. strange, eh?

So the bearings was knocking for two months driving??

Helmsman wrote

So the bearings was knocking for two months driving??

like i said i thought it was a lean mixture or something to do with fuel delivery. If I suspected rod bearings i would not have left it for 2 months. i didn't expect the noise to go away, but it has

winbasic wrote

What year is your car? I do regular Blackstone testing but I'm not sure of it's value given the car is 2012 so I understand they use a different bearing which has less trace metals in it which can be picked up by the test.

2008 E92 build date 6/08. I went from 4 ppm lead to 15 in January and then up to 30ppm in October. That's when i decided to change the bearings

Peertwelve wrote

AznSupraTT wrote

So any definitive answer other then airbox and normal sounds? I hear it on my car with the AA supercharger and obviously their DME tune.

I hate to pour gasoline onto the bonfire that is rod bearing hysteria, but my car had the exact same 'knocking' noise is the video quoted above. It could be reproduced 100% of the time by accelerating hard from 2nd or 3rd gear with the engine off-idle (aka bog the engine). the knock/ping sound would start at around 2800rpm and disappear by 3500 rpm. It first happened in September during a trip to San Francisco. I thought it was the crappy CA 91 octane gas. When i arrived home in Seattle i filled up with my normal Shell 92, but the sounds persisted. After several bad Blackstone labs reports, I had my rod bearings replaced last week and since then ( last week ) i have not been able to reproduce the noise since.. strange, eh?

I hate to say it too because people jump on you and say you're bearing hysterical but I agree. Take a few minutes to pull the oil filter and check it for any metal debris, it will cost you nothing and you can quickly rule out a major bearing fail. For it to be a bearing and sound like there would be debris. Here is mine after 2 mains went and made similar noises, very fine particles.

Cwleo wrote

Hi guys,

Is this the mechanical fluttering sound everyone is experiencing (link below) Does anyone have a solution for this issue?

I'm sorry, this just sounds terrible. Check the oil filter for fine debris.

Duk996 wrote

I'm sorry, this just sounds terrible. Check the oil filter for fine debris.

I agree . Keep in mind Cwleo his post and video dates from *11-3-2016*
He is from Malaysia . I think meanwhile he just dumped the car .

NOTE: From his statistics on his personal page , this was also his last post...