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

[Race_Doc11]

Originally Posted by ///M Power-Belgium

Yep ! That's what I said above .Same situation here , and the cold start clunk noise comes from the Vanos gears .

Saw only one person who fixed the noise by replacing the Vanos gears under BMW warranty and it was a PUMA case .

And no one understood why the noise was fixed ...Because his old Vanos gears were replaced by exactly the same new vanos gears ..

OMG this is still going! I'm glad to hear it is not causing any catastrophic engine failure.

[///M Power-Belgium]

Originally Posted by Race_Doc11

OMG this is still going! I'm glad to hear it is not causing an catastrophic engine failure.

Yes this thread is still alive . Just like our cold start clunk noise

[Stronie]

Originally Posted by ///M Power-Belgium

Doc yes , I agree with your comment .
But actually I can hear like you said 2 different kind of noises on my S65.

1- The loud single clunk noise .
2- The rattle clunk noise (sometimes 3-4-5 shorter rattle noises in 2 sec.)

I'm sure the base-cause of the noise from nr 1 + 2 are the same and I think it's *the amount* of the force that is behind it...

Video # 1 shows you the loud single clunk noise .
Video # 2 shows you the rattle clunk noise => video from #16 page 1 in this thread => http://www.m3post.com/forums/showthread.php?t=996069
And like I said above I have both => #1 + # 2

I'm 100% sure if I replaced the Vanos gears the noise would be gone , but deep pockets are required !
I know also this noise can't be healthy for our S65's , on the other hand I know a lot people over the world and they have this noise for 5-6 years ...

Note : Videos are examples and not my car .

Thanks for sharing my video. This is my car and after 6 years - 78k miles run strong, no issues. Happens on occassion after long sitting periods. NORMAL.

[///M Power-Belgium]

Originally Posted by Stronie

Thanks for sharing my video. This is my car and after 6 years - 78k miles run strong, no issues. Happens on occassion after long sitting periods. NORMAL.

I know . Hope you don't mind ? Because the noise was very loud and clear in your video.
But actually the noise is NOT NORMAL !

[CHE///MIST3]

Well, I must say that my own loud "CLACK" at start-up has now gone away completely...at least since the last several times I have cold-started it after a couple days. What's changed? I replaced the exhaust vanos gears on both banks of the motor.

I was in the process of replacing my valve cover gaskets and discovered the plastic retention cap on the exhaust gears only were starting to work themselves crookedly on the gear. Concerned, I purchased a pair of used vanos exhaust gears that were in excellent shape. They were the same mileage as mine so I installed them, slightly timed the engine, closed everything back up, and I have not heard that sound ever since.

*major shout-out to forum member DeansBimmer for selling me the parts and helping over the phone while I did this in the garage.

Of course i'm not trying to stir up a scare and say those plastic/teflon covers will come off and damage the engine in everyone's cars, but they can certainly pop loose over time and make noise. Worth a look next time you change your valve cover gaskets.

...now, if I could just resolve the 2008 MT clutch rattle in neutral while parked

GM

[GORDON.M3]

Do we have a certain conclusion to this "issue" yet?

[Shamza]

Both timing chain tensioners cheapest place to start..

[GSTE34]

Originally Posted by ///M Power-Belgium

I posted this video now 3 times on this forum ,and so here is it again to make this clunk noise very....very clear !
Note : This is not my car and actualy it is "the loudest clunk noise" i ever heard from our S65 engine !

This is the exact noise mine makes did it ever get fixed?

[GSTE34]

Originally Posted by Stronie

I posted a great video of mine. I'm certain this is what everyone is talking about. Can you guys confirm.

Also I've had this noise since day 1. Sounds terrible but I'm going to chalk this up as normal.

I have that exact sound just as loud

[BRNDNSLVRA]

Its been a thing since I bought the car last Jan. Otherwise, the car drives great. 101K+ miles and she runs like a champ. Thats the only concerning noise this thing makes.

[wfdeacon88]

Originally Posted by CHE///MIST3

Well, I must say that my own loud "CLACK" at start-up has now gone away completely...at least since the last several times I have cold-started it after a couple days. What's changed? I replaced the exhaust vanos gears on both banks of the motor.

I was in the process of replacing my valve cover gaskets and discovered the plastic retention cap on the exhaust gears only were starting to work themselves crookedly on the gear. Concerned, I purchased a pair of used vanos exhaust gears that were in excellent shape. They were the same mileage as mine so I installed them, slightly timed the engine, closed everything back up, and I have not heard that sound ever since.

*major shout-out to forum member DeansBimmer for selling me the parts and helping over the phone while I did this in the garage.

Of course i'm not trying to stir up a scare and say those plastic/teflon covers will come off and damage the engine in everyone's cars, but they can certainly pop loose over time and make noise. Worth a look next time you change your valve cover gaskets.

...now, if I could just resolve the 2008 MT clutch rattle in neutral while parked

GM

Any update? Did this fix the "issue" for you?

[BeaterM3]

Originally Posted by anom3

My theory is that the noise I was experiencing is simply good old fashion timing chain slap.

By delaying the time when the alternator gets kicked on by 1 or so seconds (a solution that has worked for me for well over a month now), it gives the motor a tiny bit more time to wind up, lubricate and get ready for the additional mechanical load the alternator gives the crank. I know the alternator doesnt directly sit on the crank, but it all ends up on the crank... Both the timing chain and the serpentine belt.

As far as why the break procedure seams to work for some while not for others, I have no idea. It didn't work for me. Worth noting the vacuum pump on our vehicles is an electrical one. It sits near the drivers side front wheel. Under the "side fender" or whatever its called. So as far as pumping the breaks and any change in mechanical load on the motor, I don't think it really applies.

Just to add my experience with this.

I have been experiencing the 1 clunk alternator sound for like a month now.

I did recently have both my tensioners and tensioner pulleys replaced prior to the noise starting.

The brake procedure has worked for me. Also, making sure all accessories being shut off before next start seems to help as well; when the clunk noise does happen, it is not as delayed and happens sooner in the start up procedure and less pronounced as well.

I will be curious if this happens once the warm/hot weather comes back around...this has only began happening when the bitterly cold weather has kicked in (i park outside).

[Oreo Cat]

136k, noise just started for me

[molen586]

Hello all.
I also have the noise on a 55k mile car. Have been reading the thread and replaced the check valved but did not read the thread fully at that point. Now I did and saw this was not the solution for anyone. Still have to see if the sound is still there.

Btw. I noticed some dealer quoted 1000USD on labor to replace them? It took me 2 hours maximum.

As the check valves can only hold pressure for a limited time I can imagine two things can happen which I did not read in this thread.

- Is there a way to check if the vanos gears are locked into position at a no pressure state? I can imagine that due to wear of the internal spring in the gears the locking pin is misaligned and does not lock the gears at start, so you hear the rattle at startup before the chambers are completely filled.
So does anyone know the locking positions of the cams, so I can check this on ISTA.
What are your thoughts on this and is there someone that did an inspection on those gears that have been replaced?

- Second though which can easily be checked. There is another non-return valve in the oil filter housing. Did anyone removed the oil filter cap to check if the housing is still to around 80% after 2 to 3 days down time?

The second thought is something I will check I only needed the car every day the last couple weeks.

[Ajolives]

Old thread revival time!!!!

So, I've had this noise for the better part of a year and a half; likewise I read the posts and thought it wasn't too concerning giving all the sound opinions from people much, much smarter than I. Fast forward to a couple weeks ago, I learned that my VANOS gear covers are cracked and basically ready to fall apart and clog my oil pickup line and/or take a lovely tour of the S65 internals.

I'm thinking maaayyybbbeee that the cover is spinning on the gear on initial startup then grabs (I see my inlet cover isn't fully aligned with the spring and pins through that little viewing hole anymore) and is causing the noise.

Or, the gear/cam gasket is old and letting oil seep after long sits gets no lubrication on initial startup until pressure is built, causing the noise (or the gasket is allowing play between the two parts, but I would imagine the center bolt wouldn't allow it). I want to say the second bank is where my noise is, so if those covers are fine I'm going to take them off and replace that gasket anyways as preventative maintenance and see what happens.

Either way, I am replacing at least two VANOS timing gears next week and four gaskets (not sure how the second bank looks but I'm not giving my hopes up) and will report back if the noise is gone after I'm done poking around in there, willing that I don't break my engine or run into any other issues in the process.

[rizioca]

And news? I would assume all is fine after numerous replies? I too have this cold start metallic noise, usually after sitting. I'm at 126k miles a 2011 E90

[TechE]

Just chiming in here. I've had this noise since I bought the car. Very noticeable if I don't start it for a week. I was under the impression the check valve replacement may help and planned to at some point.

But, for whenever reason it's stopped. The only difference is I've been taking it on short highway commutes. It's also my first oil fill with Motul and Ceratec, but I can't imagine that suddenly having a effect.

[bmwm3s65]

I had this noise since i bought my car, both on my blown engine and now on my factory refurb engine when it had 0 miles, now at 25k.

[douglee25]

Bought mine with 60k. It has almost 140k now. Noise is still there occasionally. I'm not worried.

[duk]

It is common noise

Just means your engine will blow up sooner or later

It'll be ok