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

[anom3]

heya mike... good to hear you chime in on this.

i actually coded off all my bulb checks, switched the light position to 0 and disabled DRL's in my cic (can be done via .MAN as well as i'm sure you know). and i kept an eye on the wall on the other side of the path in the underground. NO lights at all, before, during and after start.

didnt help, noise appeared again.

keep us posted tho.

Originally Posted by Mike Benvo

Replaced check valves on my 08 motor and it changed the sound of the noise slightly, but still did it.

They all do it, especially when sitting for awhile. It's more prominent when parked on a hill too. I've heard it on a bone stock 2013 with under 3k on the clock.

Stating that this is tune related is off rhythm by quite a few beats. But some people like to be ridiculous.

I think an interesting point made earlier is about the lights.. Now that I think about it, every time my car is started the lights fire on because I'm in a garage. Just for kicks, in going to start the car with the switch to the off position. I'll be damned if it doesn't make the noise.... I can't imagine that being related, but will report back. If anything i would think that it may be related to voltage drop as the xenons fire and the starter disengages. Nice catch anon m3!

I'm also going to throw a battery tender on there to ensure the voltage is up there, as my battery probably isn't the strongest at this point.

[anom3]

just a quick update to those that care... my check valves were replaced today.

unfortunately only 3 of the 4 were done, cause the shop ran out of time. they gonna do the last one mon / tues next week (long weekend here, thursday off, most people taking friday off).

i'm letting the car 'sit' as we speak. going to let it sit over night + what its been already sitting. by tomorrow morning it will have been sitting for well over 12 hours.

by the way, a new development:

so i noticed the following, easiest to explain in a Hour:Minute:Second play by play:

00:00:00 : Car has been sitting for a number of hours, lets say 8, after doing a normal drive to the super market, or a highway drive.
00:00:01 : Start the car
00:00:02 : GRIND!
00:00:05 : Turn off the car
00:00:06 : Star the car
00:00:07+ : No GRIND

( so far the above has been explain in my original post, the grind happens, only on first start, during cold start )

the following is new:

00:00:10 : car off.

now, if I let the car sit for another 8+ hours, but in the previous "run cycle" (dont really know what to call it, you understand tho) the oil has not reached anywhere near full temperature, the noise is MUCH quieter the next start. so engine (OIL!) temp has some sort of influence on weather the noise takes place or not.

08:00:00 : start
08:00:02 : GRIND, but MUCH MUCH quieter. at times, completely not noticeable.

i have observed the above 4 times now. this week has been a quiet one for me driving wise, so there were a few times i did a quick start + stop without actually leaving anywhere which is what lead me to this observation.

hope this makes sense.

yet more evidence pointing towards this being some sort of 'oil bleeding' issue. seeing as after a quick on + off, the oil is probably quite thick and has a harder time bleeding down?

we'll see how the 3 of the 4 check valves do tomorrow. shity that only 3 were done, but my mechanic is swamped, they just had no time today :/ all good tho, 4th one gonna be done for sure, paid for labor already actually

thanks!

oh, in a few hours ill grab the old ones from my vehicle and do a couple of snaps for those who are interested.

[anom3]

so i got impatient, and went to start the car.

it was sitting for 6 hours.

3 of 4 check valves changed, 1 remains to be changed (early next week).

noise still there although it only did a single "clack", but still, very much there.

*sigh*

what now?

[///M Power-Belgium]

Originally Posted by anom3

just a quick update to those that care... my check valves were replaced today.

unfortunately only 3 of the 4 were done, cause the shop ran out of time. they gonna do the last one mon / tues next week (long weekend here, thursday off, most people taking friday off).

i'm letting the car 'sit' as we speak. going to let it sit over night + what its been already sitting. by tomorrow morning it will have been sitting for well over 12 hours.

by the way, a new development:

so i noticed the following, easiest to explain in a Hour:Minute:Second play by play:

00:00:00 : Car has been sitting for a number of hours, lets say 8, after doing a normal drive to the super market, or a highway drive.
00:00:01 : Start the car
00:00:02 : GRIND!
00:00:05 : Turn off the car
00:00:06 : Star the car
00:00:07+ : No GRIND

( so far the above has been explain in my original post, the grind happens, only on first start, during cold start )

the following is new:

00:00:10 : car off.

now, if I let the car sit for another 8+ hours, but in the previous "run cycle" (dont really know what to call it, you understand tho) the oil has not reached anywhere near full temperature, the noise is MUCH quieter the next start. so engine (OIL!) temp has some sort of influence on weather the noise takes place or not.

08:00:00 : start
08:00:02 : GRIND, but MUCH MUCH quieter. at times, completely not noticeable.

i have observed the above 4 times now. this week has been a quiet one for me driving wise, so there were a few times i did a quick start + stop without actually leaving anywhere which is what lead me to this observation.

hope this makes sense.

yet more evidence pointing towards this being some sort of 'oil bleeding' issue. seeing as after a quick on + off, the oil is probably quite thick and has a harder time bleeding down?

we'll see how the 3 of the 4 check valves do tomorrow. shity that only 3 were done, but my mechanic is swamped, they just had no time today :/ all good tho, 4th one gonna be done for sure, paid for labor already actually

thanks!

oh, in a few hours ill grab the old ones from my vehicle and do a couple of snaps for those who are interested.

That's what i said about driving the car every day and longer trips ,than my clunk noise is gone !
For example...i take here out in the weekend a drive her for 200 Miles ,well than the clunk noise is gone for at least 10-15 day's , and after when she sits again a week in my garage the clunk story starts all over again !
And i have news too ....From my BMW-Dealer,they have found something in their database !
So i had the next question...so what is the cause of the clunk noise ?
Their answer was....we can make an appointment and we will check the cause of the clunk noise !
Me again....so what is the cause of the problem ?
They...Do you want an appointment or not ?
Me...I don't bring in my car when i don't know the cause or what you are planning to do with my car !
Conclusion....
They don't know what it is...or they are afraid that i'm going after i know the cause to another dealer !
So me again...when you tell me the cause you have my appointment !
They.....no !
Me...why not ?
They...if you want if we look into the problem it's up to you !
Me...again... but what is the problem ?
They...yes or no ?
Me...and finally i said it with pleasure that they are actualy a bunch of idiots !!
End of conversation and back to .... 0 !
Damn these dealers these day's , business first and service after , no thank you !

[anom3]

not too sure how you purchased the car etc etc etc... i bought from a private seller so going to the dealer is not an option for me. but that does sound shity

i still have 1 more check valve to change, they didnt have time today. its all paid for so gonna get it done anyways.

we'll see how it performs over the next few days, and ill post if there has been any improvements.

being totally honest here, it does sound better. it has turned from a multiple grind like noise, to a single "clack". but that could be because i only gave the car about 6 hours to cool.

i plan on pursuing this further btw. next step will be to do my best to localize the location where the noise is coming from. kind of hard to do on my own as i need help starting the car while my head is under the hood, but i got my gf to help with that

will keep everyone posted.

Originally Posted by ///M Power-Belgium

I have news too ....From my BMW-Dealer,they have found something in their database !
So i had the next question...so what is the cause of the clunk noise ?
Their answer was....we can make an appointment and we will check the cause of the clunk noise !
Me again....so what is the cause of the problem ?
They...Do you want an appointment or not ?
Me...I don't bring in my car when i don't know the cause of what you are planning to do with my car !
Conclusion....
They don't know what it is...or they are afraid that i'm going after i know the cause to another dealer !
So me again...when you tell me the cause you have my appointment !
They.....no !
Me...why not ?
They...if you want if we look into the problem it's up to you !
Me...again... but what is the problem ?
They...yes or no ?
Me...and finally i said it with pleasure that they are actualy a bunch of idiots !!
End of conversation and back to .... 0 !
Damn these dealers these day's , business first and service after , no thank you !

[///M Power-Belgium]

Originally Posted by anom3

not too sure how you purchased the car etc etc etc... i bought from a private seller so going to the dealer is not an option for me. but that does sound shity

i still have 1 more check valve to change, they didnt have time today. its all paid for so gonna get it done anyways.

we'll see how it performs over the next few days, and ill post if there has been any improvements.

being totally honest here, it does sound better. it has turned from a multiple grind like noise, to a single "clack". but that could be because i only gave the car about 6 hours to cool.

i plan on pursuing this further btw. next step will be to do my best to localize the location where the noise is coming from. kind of hard to do on my own as i need help starting the car while my head is under the hood, but i got my gf to help with that

will keep everyone posted.

Damn... feel realy sorry for you man !
But one thing is for sure > THIS > "# 60" on page 3 ! <
It's from member "M3PO" and i've reading some stuff from him,and i can tell you this guy knows what he's talking about !
So he posted in # 60 that 30K miles ago he had the VANOS-Gears replaced and till today the clunk noise is gone !
So personal i think we need to look into this direction !
THE VANOS-GEARS............

[anom3]

yep i saw that.

only issue is the vanos gear replacement is a bit expensive

looking at the diagrams its roughly 1K USD per side ( http://www.realoem.com/bmw/showparts...22&hg=11&fg=25 ).

if i knew for sure this is where the issue was i would do it.

Originally Posted by ///M Power-Belgium

Damn... feel realy sorry for you man !
But one thing is for sure > THIS > "# 60" on page 3 ! <
It's from member "M3PO" and i've reading some stuff from him,and i can tell you this guy knows what he's talking about !
So he posted in # 60 that 30K miles ago he had the VANOS-Gears replaced and till today the clunk noise is gone !
So personal i think we need to look into this direction !
THE VANOS-GEARS............

[///M Power-Belgium]

Originally Posted by anom3

yep i saw that.

only issue is the vanos gear replacement is a bit expensive

looking at the diagrams its roughly 1K USD per side ( http://www.realoem.com/bmw/showparts...22&hg=11&fg=25 ).

if i knew for sure this is where the issue was i would do it.

Exactly the same thing here...If we knew for sure !
And i knew it's 1K USD per side + don't forget the labor,and personal i think it's a lot of labor on the Vanos !
Also this is US price, here in Belgium it's about X 2 the US price !
But when i was 100 % sure i would do it in a heart beat !
But again... If we knew for sure.....
Damn ?!?!
And also.... "DAMN YOU BMW" !!!They knew this was a worldwide problem !
And what they have done was..........NOTHING !!!

[Petros]

Just to add fuel to the fire, I changed my oil today and when i started the engine there was a clunk just the first time. Never happened again. Seems like you're onto something with the theory about oil draining out of the vanos gears.

[s85e90]

Originally Posted by Petros

Just to add fuel to the fire, I changed my oil today and when i started the engine there was a clunk just the first time. Never happened again. Seems like you're onto something with the theory about oil draining out of the vanos gears.

Yes. Every car does this. Unless you prime the car to build oil pressure after a change you are essentially starting a dry motor that takes a second to build oil pressure into the heads. This clunk from the car sitting is essentially the same thing. I don't know if people can actually see my posts as it's been written here before as well. IMO it's not a big deal just an annoying noise.

[FormulaMMM]

Originally Posted by anom3

so i got impatient, and went to start the car.

it was sitting for 6 hours.

3 of 4 check valves changed, 1 remains to be changed (early next week).

noise still there although it only did a single "clack", but still, very much there.

*sigh*

what now?

Can you please try the starter? (Malek's theory.) I had a starter fail in my E39 M5 years ago and the sound wasn't far off this E9X issue.

As far as the seriousness of the issue -- common to both of my E90 M3's, and present over almost 50k miles combined. Both engines are flawless post-startup. No engine related problems other than an ignition coil for my 6MT. If this was a sign of a more critical issue, I/we would know by now. I say "we" because at this point we know it must be present on hundreds of M3's (or more), with hundreds of thousands of miles collectively. Other than M3PO we know of no one who has had the issue successfully addressed, so then where are all of the critical engine issues emanating from the noise?

That said, it would be cool if you figured it out conclusively... Either assign it to the starter, or confirm M3PO's repair.

[anom3]

just fyi, as far as the car being flawless post startup, same situation here. car rips, no codes stored in the ecu's, and most of all, it feels great. no hesitation, lots of torque, all that good stuff.

i am not an expert on this car stuff, so i'm learning as i go along, but the one thing that makes me think this may not be the starter is the fact that there is a pause between when the engine makes ignition and the noise starts.

see this post ( i'm sure you already have, but, http://www.m3post.com/forums/showpos...5&postcount=20 ).

there is a distinct 0.5 sec or so pause between when the engine starts firing on its own and when the noise takes place.

wouldnt a starter issue be present RIGHT away?

someone want to chime in?

Originally Posted by FormulaMMM

Can you please try the starter? (Malek's theory.) I had a starter fail in my E39 M5 years ago and the sound wasn't far off this E9X issue.

As far as the seriousness of the issue -- common to both of my E90 M3's, and present over almost 50k miles combined. Both engines are flawless post-startup. No engine related problems other than an ignition coil for my 6MT. If this was a sign of a more critical issue, I/we would know by now. I say "we" because at this point we know it must be present on hundreds of M3's (or more), with hundreds of thousands of miles collectively. Other than M3PO we know of no one who has had the issue successfully addressed, so then where are all of the critical engine issues emanating from the noise?

That said, it would be cool if you figured it out conclusively... Either assign it to the starter, or confirm M3PO's repair.

[anom3]

hi petros.

i just ordered two of these last night:



the plan is:

a) put one in my left ear, one in my right ear.
b) place both on vanos units (one on left, one on right).
c) have gf start the car.
d) see if the noise is any louder on left / right vanos.

will keep everyone posted.

Originally Posted by Petros

Just to add fuel to the fire, I changed my oil today and when i started the engine there was a clunk just the first time. Never happened again. Seems like you're onto something with the theory about oil draining out of the vanos gears.

[FormulaMMM]

Originally Posted by anom3

see this post ( i'm sure you already have, but, http://www.m3post.com/forums/showpos...5&postcount=20 ).

there is a distinct 0.5 sec or so pause between when the engine starts firing on its own and when the noise takes place.

wouldnt a starter issue be present RIGHT away?

someone want to chime in?

It is true that when the starter on my M5 was on it's way out, it was immediately present on startup/as the car cranked, if I remember correctly. But the sounds are very similar.

Malek's suggestion is that it is the starter disengaging. In that case, maybe there would be a delay --

It is the starter disengaging which can usually make a loud metallic sound as the starter gear pops back.

[anom3]

hey just wanted to chime in quickly... i totally understand your attitude towards this issue. ugh, hope im not misusing that word, don't mean it in a bad way i assure you...

but the way i look at it, the car i recently bought, is completely flawless, except for this and the clunky flywheel / clutch ( i have an 'older' 07 design 6mt flywheel / clutch, which bmw upgraded in 2009 i believe due to complains about the noise ).

i also firmly believe there is a solution to this. as many as are vocal about this cold start noise, my understanding is there are WAY more that dont exhibit this noise.

so yea, just fyi, i see all your posts... not ignoring them... but i have funds and am willing to spend them to at least try and resolve this issue

if this can be diagnosed to one side of the vanos, thats probably as far as i would go trying to resolve it.

game plan as of now looks as follows:

1) check valves changed (almost done, as mentioned 1 valve left, gonna be done monday probably...)
2) going to have the chain tensioners replaced as they are fairly inexpensive and fairly easy to access (according to the diags anyways).
3/4 undecided what order) starter replace and one side of the vanos gears.
5) give up

Originally Posted by s85e90

Yes. Every car does this. Unless you prime the car to build oil pressure after a change you are essentially starting a dry motor that takes a second to build oil pressure into the heads. This clunk from the car sitting is essentially the same thing. I don't know if people can actually see my posts as it's been written here before as well. IMO it's not a big deal just an annoying noise.

[Race_Doc11]

I achieved the same results by changing the tensioners more than a year ago. In a year a half now I didn't hear the clunk except once or twice. Every time I start the car now I turn the ignition on wait like 10 -20 seconds with my foot on the break then start the car I only get one single clunk that is not noticeable at all. The starter theory is another thing I might look into.

Can someone explain the mechanism of starting the car? I mean what exactly happen when we press the brakes? it must enables something in order to let the car start.

Originally Posted by anom3

just a quick update to those that care... my check valves were replaced today.

unfortunately only 3 of the 4 were done, cause the shop ran out of time. they gonna do the last one mon / tues next week (long weekend here, thursday off, most people taking friday off).

i'm letting the car 'sit' as we speak. going to let it sit over night + what its been already sitting. by tomorrow morning it will have been sitting for well over 12 hours.

by the way, a new development:

so i noticed the following, easiest to explain in a Hour:Minute:Second play by play:

00:00:00 : Car has been sitting for a number of hours, lets say 8, after doing a normal drive to the super market, or a highway drive.
00:00:01 : Start the car
00:00:02 : GRIND!
00:00:05 : Turn off the car
00:00:06 : Star the car
00:00:07+ : No GRIND

( so far the above has been explain in my original post, the grind happens, only on first start, during cold start )

the following is new:

00:00:10 : car off.

now, if I let the car sit for another 8+ hours, but in the previous "run cycle" (dont really know what to call it, you understand tho) the oil has not reached anywhere near full temperature, the noise is MUCH quieter the next start. so engine (OIL!) temp has some sort of influence on weather the noise takes place or not.

08:00:00 : start
08:00:02 : GRIND, but MUCH MUCH quieter. at times, completely not noticeable.

i have observed the above 4 times now. this week has been a quiet one for me driving wise, so there were a few times i did a quick start + stop without actually leaving anywhere which is what lead me to this observation.

hope this makes sense.

yet more evidence pointing towards this being some sort of 'oil bleeding' issue. seeing as after a quick on + off, the oil is probably quite thick and has a harder time bleeding down?

we'll see how the 3 of the 4 check valves do tomorrow. shity that only 3 were done, but my mechanic is swamped, they just had no time today :/ all good tho, 4th one gonna be done for sure, paid for labor already actually

thanks!

oh, in a few hours ill grab the old ones from my vehicle and do a couple of snaps for those who are interested.

[anom3]

i have a 6mt and live in a quite flat city, so rarely, if ever, do i press on the break when starting the car. i tried the break routine, but got the noise.

but, "previous run cycle" engine temperature (oil) has a clear effect on this. if the last "run cycle" doesnt warm the oil / engine up, the noise is almost gone.

just watch this video, i'm tired of writing. sorry for all the umm, aaaa... wierd feeling talking to myself



the noise was so quiet this time around, i began moving the phone away only to hear it ever so slightly.

Originally Posted by racedoc11

I achieved the same results by changing the tensioners more than a year ago. In a year a half now I didn't hear the clunk except once or twice. Every time I start the car now I turn the ignition on wait like 10 -20 seconds with my foot on the break then start the car I only get one single clunk that is not noticeable at all. The starter theory is another thing I might look into.

Can someone explain the mechanism of starting the car? I mean what exactly happen when we press the brakes? it must enables something in order to let the car start.

[///M Power-Belgium]

Originally Posted by anom3

i have a 6mt and live in a quite flat city, so rarely, if ever, do i press on the break when starting the car. i tried the break routine, but got the noise.

but, "previous run cycle" engine temperature (oil) has a clear effect on this. if the last "run cycle" doesnt warm the oil / engine up, the noise is almost gone.

just watch this video, i'm tired of writing. sorry for all the umm, aaaa... wierd feeling talking to myself



the noise was so quiet this time around, i began moving the phone away only to hear it ever so slightly.

My clunk noise is never louder than yours in the last video !
Note ; Car was sitting 7 days in my garage,and started her today with the strange brake procedure,and no clunk noise !
After 9 hours started the car again after work, used the brake procedure again and no clunk noise !
Said it before,the brake procedure works for me ,this brake procedure comes actualy from racedoc11,and i said to myself why not and give it a try !
So no clunk noise here when using the brake procedure ,and it seems like it works only on DCT cars !
What can be the link between the clunk noise and the brake procedure ?
Well i have no anser and it sounds even unbelievable.....see no link between them !
Also thanks for posting the video !

[anom3]

not sure if this has been posted before... but i found a video, posted a number of years ago on youtube by someone else who has the EXACT same noise.

[FormulaMMM]

Originally Posted by anom3

not sure if this has been posted before... but i found a video, posted a number of years ago on youtube by someone else who has the EXACT same noise.

Yes... this was surprising to you? You'll find many more on youtube including mine if you listen to enough cold start videos. This is not a unique issue.

[ivad32]

Originally Posted by FormulaMMM

Yes... this was surprising to you? You'll find many more on youtube including mine if you listen to enough cold start videos. This is not a unique issue.

What is the issue?

[SenorFunkyPants]

Interesting read. My 2009MY car doesn't make this noise no matter how long my car stands - so no, every car doesn't do it
The way the sound occurs (cold start after standing) does seem to point to some sort of VANOS issue, although its hard to visualize what sort of internal event could be happening to produce such a sound. AIUI the VANOS is in the default position at start up and tickover, the only parts that would require instant oil pressure are the timing chain tensioners - 75 psi should be more than enough to work the tensioners and if they were the cause why doesn't it make the noise the instant the engine starts? But if replacing VANOS components fixes the issue then it does sounds like the most likely fix
Regarding the starter motor - although it sounds unlikely, the grinding does actually sound like the noise you get if you try and start a car that is already running, where the starter gear hits the already turning flywheel teeth. Pressing the brake pedal in a DCT (clutch pedal in MT) releases the interlock and allows the starter to turn to start the engine - I guess there could be some sort of electrical glitch that causes the starter to momentarily try and re-engage despite having already started the engine?
A push start test (in an MT) is the next step to see if it eliminates this possibility.