E92 M3 - Metallic clunk / grind on cold start (With 3 Videos + Image of Noise)

[///M Power-Belgium]

Originally Posted by FormulaMMM

Yep, this result was with my 6MT. I'll verify later on this week. If I go 2 for 2 it's no coincidence because my 6MT has been making the noise after any period of inactivity for almost 3 years and 35k miles.

Same here for 2 years and 31K !
For the last month i've had i think 10-12 cold starts and everytime without the clunk noise !
So for me personal it works 100 % !

[Race_Doc11]

I'm glad I contributed something to the M3 community It was random but I noticed if I do it the car doesn't have the clunk so I kept doing it while I thought it cant be true. I was very hesitant to share it here fearing of the reactions but finally I did and was really relieved and glad when I heard it works for others as well. I hope someone who knows these motors can link everything together. I got my car in Oct 2008 and shortly after it started to have the clunk. Currently the car has 38000 miles.

Originally Posted by FormulaMMM

Quote:


Originally Posted by ///M Power-Belgium View Post

Maybe we should post a new thread with the name...."The mystery of the brake procedure "
BTW...about the "misguidance" of the brake procedure , it was the same here !And thought it works only for DCT but see now your's 6MT ?
I saw the comment of racedoc11 about this and thought...i'll try it !
The result you know by now....

Yep, this result was with my 6MT. I'll verify later on this week. If I go 2 for 2 it's no coincidence because my 6MT has been making the noise after any period of inactivity for almost 3 years and 35k miles..

[FormulaMMM]

Originally Posted by ///M Power-Belgium

Same here for 2 years and 31K !
For the last month i've had i think 10-12 cold starts and everytime without the clunk noise !
So for me personal it works 100 % !

Well, got impatient and went over to the garage where I've got my 6MT stored and gave it another shot. This time conducted the full brake procedure, but no luck. Here's the vid

Let the car idle for about 45 seconds, restarted the camera and immediately did 3 follow up starts plus a rev. Normal, healthy as can be, which is all this engine's ever been with the exception of an ignition coil and this damn noise after periods of inactivity.

Again, seems likely to be a lubrication, or maybe a vanos adjustment issue as was detailed elsewhere in this thread (EDIT here: http://www.m3post.com/forums/showpos...&postcount=134). Sometimes on starts that are not full cold starts, but when the engine has cooled a bit I hear a small click that is a fraction of the noise heard in the video. (I should add on both my 6MT and DCT.)

For kicks, my cold start video from '12 some 25k miles ago...

[///M Power-Belgium]

Originally Posted by FormulaMMM

Well, got impatient and went over to the garage where I've got my 6MT stored and gave it another shot. This time conducted the full brake procedure, but no luck. Here's the vid

Let the car idle for about 45 seconds, restarted the camera and immediately did 3 follow up starts plus a rev. Normal, healthy as can be, which is all this engine's ever been with the exception of an ignition coil and this damn noise after periods of inactivity.

Again, seems likely to be a lubrication, or maybe a vanos adjustment issue as was detailed elsewhere in this thread (I think). Sometimes on starts that are not full cold starts, but when the engine has cooled a bit I hear a small click that is a fraction of the noise heard in the video. (I should add on both my 6MT and DCT.)

For kicks, my cold start video from '12 some 25k miles ago...

Yep,loud and clear ! Damn man !
In the first video i can hear the clunk and even more,like a clunk and a rattle right after the clunk !
I never had the clunk + rattle but in the posted videos of OP (anom3) i've heard also the clunk + rattle , it's almost a machine gun for about 1-2 secondes !
Sorry man,then i need to say that it only works for DCT cars > look at racedoc11 comment here just above,he has also DCT
BTW...thanks for posting the videos !

[FormulaMMM]

Originally Posted by ///M Power-Belgium

Yep,loud and clear ! Damn man !
In the first video i can hear the clunk and even more,like a clunk and a rattle right after the clunk !
I never had the clunk + rattle but in the posted videos of OP (anom3) i've heard also the clunk + rattle , it's almost a machine gun for about 1-2 secondes !
Sorry man,then i need to say that it only works for DCT cars > look at racedoc11 comment here just above,he has also DCT
BTW...thanks for posting the videos !

Yeah, I guess it was just coincidental with my 6MT last week. Oh well.

[Race_Doc11]

It looks like it only works for DCT. What about pressing the clutch and the brake together the same way we do with the brake procedure?. With all the respect to all the posts claiming the noise is normal I don't think so. Not harmful yes but not normal. I must have had the noise since 2009.

Originally Posted by ///M Power-Belgium

Yep,loud and clear ! Damn man !
In the first video i can hear the clunk and even more,like a clunk and a rattle right after the clunk !
I never had the clunk + rattle but in the posted videos of OP (anom3) i've heard also the clunk + rattle , it's almost a machine gun for about 1-2 secondes !
Sorry man,then i need to say that it only works for DCT cars > look at racedoc11 comment here just above,he has also DCT
BTW...thanks for posting the videos !

[psu.m3]

I visited BMW dealer yesterday and consulted with service adviser about the cold start noise. i got the estimate for the replacing 4vanos gears. Since my warranty expired long time ago(09 model with 30000km) its going to cost me approximately $4000 US

I'm very confused... even if i fix the noise by replacing 4 vanos gears, there's no guarantee that noise will go away for at least another 50000km. I might start to hear them again maybe 20000km later...

Lots of LCI models(2012~13) with low mileage M3s are experiencing clank noise so i think noise will come back sooner than people think. i will be happy to spend $4k if there's guarantee that noise will go away for at least 2~3years(or 50000km) but feel like its gamble.

Except for clank noise, my car's in perfect condition. Never been abused, or tracked. Always warmed up properly, and my oil change intervals were no more than 3000km(or every 3months). No collision history.



I found some exhaust video clips from the youtube that i want to share

it seems that this clank noise is very common on e9x m3

i think, owners in the vid are not aware of the clank noise, or maybe

they just dont care idk

[///M Power-Belgium]

Agree with you ! I know.....
Is your car DCT or 6MT ?

[psu.m3]

Originally Posted by ///M Power-Belgium

Agree with you ! I know.....
Is your car DCT or 6MT ?

Mine's DCT

[FormulaMMM]

Originally Posted by psu.m3

they just dont care idk

I care insofar as it's annoying to not clearly understand what the hell is going on after all this time. And it's unfortunate that for that 1 second the S65 doesn't make a nice noise.

But $4k to fix (perhaps temporarily) the unpleasant, intermittent cold start clunk/grind? No thanks.

Nice collection of video evidence on the commonness of the issue btw.

[///M Power-Belgium]

Originally Posted by psu.m3

Mine's DCT

DCT ..Perfect ! The same here....
I realy would love if you could try this when possible "# 4"on this page >http://www.m3post.com/forums/showthr...3#post16319163
Now....we call this the brake procedure and works perfect for racedoc11 and me,also both with DCT !
Please update your result and thanks in advance....

[psu.m3]

Originally Posted by ///M Power-Belgium

DCT ..Perfect ! The same here....
I realy would love if you could try this when possible "# 4"on this page >http://www.m3post.com/forums/showthr...3#post16319163
Now....we call this the brake procedure and works perfect for racedoc11 and me,also both with DCT !
Please update your result and thanks in advance....

Thanks for the info. I'll give it a try

[anom3]

great collection of videos! thanks!

quick question : when you spoke to your BMW dealer, did they confirm this is coming from the vanos? or just followed along with you saying it was vanos related?

thanks.

Originally Posted by psu.m3

I visited BMW dealer yesterday and consulted with service adviser about the cold start noise. i got the estimate for the replacing 4vanos gears. Since my warranty expired long time ago(09 model with 30000km) its going to cost me approximately $4000 US

I'm very confused... even if i fix the noise by replacing 4 vanos gears, there's no guarantee that noise will go away for at least another 50000km. I might start to hear them again maybe 20000km later...

Lots of LCI models(2012~13) with low mileage M3s are experiencing clank noise so i think noise will come back sooner than people think. i will be happy to spend $4k if there's guarantee that noise will go away for at least 2~3years(or 50000km) but feel like its gamble.

Except for clank noise, my car's in perfect condition. Never been abused, or tracked. Always warmed up properly, and my oil change intervals were no more than 3000km(or every 3months). No collision history.



I found some exhaust video clips from the youtube that i want to share

it seems that this clank noise is very common on e9x m3

i think, owners in the vid are not aware of the clank noise, or maybe

they just dont care idk

[lsmkr01]

Originally Posted by anom3

great collection of videos! thanks!

quick question : when you spoke to your BMW dealer, did they confirm this is coming from the vanos? or just followed along with you saying it was vanos related?

thanks.

That clank sound is the valve opening to allow the secondary air pump flow through the exhaust during cold start.

[anom3]

i dont think so.

i have 'looked' at the sound a few times, and there is actually a succession of multiple knocks in a row. most recordings i have 'looked' at had 6-8 very quickly one after another.

plus, my secondary air pump is disabled via tune (noise was there before the tune went in btw).

have a look at this, this does not sound like a valve opening:

Originally Posted by lsmkr01

That clank sound is the valve opening to allow the secondary air pump flow through the exhaust during cold start.

[lsmkr01]

Originally Posted by anom3

i dont think so.

i have 'looked' at the sound a few times, and there is actually a succession of multiple knocks in a row. most recordings i have 'looked' at had 6-8 very quickly one after another.

plus, my secondary air pump is disabled via tune (noise was there before the tune went in btw).

have a look at this, this does not sound like a valve opening:

That sound right there was way different than the single clank that could be heard on that long chain of videos. if the sound is only during cold start is can possibly just be attributed to the gear or other internal not having oil lubrication at the moment of the start. Does that sound occur during a hot start or while the car is already running?

[anom3]

nope.

a) noise only occurs on cold start.
b) noise only happens the first time in the sense: start -> noise -> off right away -> start again -> no noise again (until it sits for 6-8 hours).
c) noise is not present EVER during warm starts, or even if the car has sat for as little as 4 hours. it usually appears around the 6-8 hour mark.

Originally Posted by lsmkr01

That sound right there was way different than the single clank that could be heard on that long chain of videos. if the sound is only during cold start is can possibly just be attributed to the gear or other internal not having oil lubrication at the moment of the start. Does that sound occur during a hot start or while the car is already running?

[s85e90]

This thread is ridiculous.

[anom3]

why so negative?

a group of complete strangers from all corners of the earth, collaborating to resolve an issue that affects them all.

nothing ridiculous here.

Originally Posted by s85e90

This thread is ridiculous.

[bradleyland]

Anom3, the sound you're hearing is completely different than what most of the guys in this thread are addressing. They're addressing the single "clank" sound that is (apparently) addressed by their brake pedal procedure. The problem you're having here is that most of the people in this thread wouldn't know a valve lifter from a check valve if you laid them out in front of them.

Unfortunately, your thread is full of useless clutter now. The sound in your post #258 is not the same sound that they're addressing, so you'd be well advised to ignore those comments. They're not going to get you anywhere.

The sound in the video in #258 sounds very much to me like lifter knock, or possibly cam chain slap. Listen to the lifter knock in this video:

That is the sound of a lifter knocking on a single cylinder, which is why the rate of the knock is so slow. Notice how similar the sound is to your car though. Keep in mind that this is a truck engine, so there is only one cam lifter actuated per intake/exhaust event. In the S65, you have four valves per cylinder, so there are two cam lifters per intake/exhaust event.

The rate of knocking in your engine definitely sounds like it's once per cylinder ignition event, which would also correspond with a single cam rotation. In my opinion, your knocking is coming from one of a handful of sources:

1) Lifter knock. The lifters in the S65 are hydraulic. Low oil pressure can cause lifter knock, and you mentioned earlier that you're seeing a dip in oil pressure during startup.

2) Knock related to engine vibration. During startup, your engine spins up a large mass of metal, which takes a minute to settle in to a cycle of equilibrium. During this startup, each cylinder firing event causes a lot of shockwaves that go through the entire engine. This can cause objects that are attached to the engine and reciprocating assembly to "slap".

IMO, you need to find someone local with the talent to diagnose it. Using those stethoscopes effectively is a real trick. They also make them with metal rods attached to them, instead of the sound membrane. It allows a technician to touch it to part of an engine and pick up sounds transmitted through the material instead of the air. That is, IMO, the only way you're going to get to the bottom of this.

[psu.m3]

I have long experience with the e39 m5, i know what traditional vanos rattle sound like. My current e92 m3 also have this traditional vanos rattle.
when i leave my car parked for extensive period of time(least 7days). I'm used to that traditional vanos sound, and i don't really care...
however the sharp metallic clank sound similar to piston knock is what im irritated about.

The duration of the clank noise vary time to time for my car. sometimes its single clank, other time there might be series of clanks. idk whats causing the difference. vids i posted, there all have same noise, just recorded with difference devices, locations, etc. People who are irritated, or used to hearing this noise will know right away that they are the same noise lol

this video has two noises(traditional vanos rattle + metallic clank noise)

no vanos rattle, clank noise only

[psu.m3]

Originally Posted by anom3

great collection of videos! thanks!

quick question : when you spoke to your BMW dealer, did they confirm this is coming from the vanos? or just followed along with you saying it was vanos related?

thanks.

Few days ago, just went to the dealer for cost estimate for 4vanos gears, but
last month dealer had my car for few days, i also provided them with recorded audio files and where to look for. just by hearing the audio file SA suspected starter motor but it turned out to be perfect working condition. SA said sound might be coming from passenger side vanos area but his not sure 100%. SA also checked PUMA cases but there's no related case#