Cold Weather Rattle from front end

[Walt White Coupe]

So I got my 2013 650ix this past summer. Everything was fine until this morning with temps in the mid 20's and start the car and as soon as I get to ~ 20 mph I hear what I would describe as a "rattle" from the front end. And it was not subtle. Was not speed sensitive other than I had to go about 20 mph before I hear it. Was not engine speed sensitive. So I drive about 4 miles, stop at a store and when I get back in and and drive off the car is quiet as can be with no rattle. Someone has to know what is causing this. Anyone?

And on a side note: Does anyone know if this car is subject to what is called the"N63 Customer Care Package"?

[ezmaass]

I'd probably wait to see if it returns before getting too concerned. How did it sound, exactly? Any chance it was some kind of debris that got caught somewhere and fell off, came loose, etc, when you came to your destination?

The N63 was a troubled engine. I know the switch on the F10 occurred with the LCI MY'14+ but haven't followed when the change occurred on the 6-series. From what I've looked up, it appears that 650's produced between 3/11 - 7/12 are included in the recall, which would seem to include through MY12 but not MY13+ (assuming they started production in mid 2012). From what I can see, the '13 already switched to the N63TU, which isn't impacted by this. Correct me if I'm wrong.

[Walt White Coupe]

Originally Posted by ezmaass

I'd probably wait to see if it returns before getting too concerned. How did it sound, exactly? Any chance it was some kind of debris that got caught somewhere and fell off, came loose, etc, when you came to your destination?

The N63 was a troubled engine. I know the switch on the F10 occurred with the LCI MY'14+ but haven't followed when the change occurred on the 6-series. From what I've looked up, it appears that 650's produced between 3/11 - 7/12 are included in the recall, which would seem to include through MY12 but not MY13+ (assuming they started production in mid 2012). From what I can see, the '13 already switched to the N63TU, which isn't impacted by this. Correct me if I'm wrong.

It has the N63TU engine so that's good. No debris. The best way to describe the noise is a "rattle" and not changing with speed. The car is normally so quiet that any abnormality is very apparent. The fact that it totally goes away is also good. I think it's going to be a cold temperature constant thing till the engine warms up. She goes in for the final 4 year warranty inspection in March so I'm not really that concerned about it but like to know what's going on and others experiences.

[Bored of Audi]

I have the same on a 640d with VDC, after around 2 miles the rattle just goes.

I thought it was suspension related and the VDC waking up on a cold morning ?? but its been in 4 times now and they can't re-create it. By the time I drive to the dealers its gone. it is certainly accentuated when you go over small undulations in the road surface.

I only keep cars like this for three years so whilst it disappears after a couple of miles and it drives well not a lot I can do.

[Walt White Coupe]

An update. The rattle is still there. Seems to be occurring with temps below 30 degree F until the car warms up. Still feels like something in the suspension. I can't see it being the belt tensioner because if it were, the noise/rattle would change with engine rpm and it is not affected by the speed of the car or rpm of the engine.

[Walt White Coupe]

So I tried to capture the sound of rattle that we are getting from the front end when the temps are 30 degrees or lower. It's the low rumble you hear that I'm concerned about. The video is looped once. This is driving over a smooth road.

Link:

[Walt White Coupe]

A little more information:

When this was happening I tried all 4 suspension settings and there was absolutely no change in the sound.

It seems the colder it is, the more obvious the knocking is. This past summer I took a trip to Nova Scotia and I had never heard any of this before. (Note: I bought this car about 2 months earlier) One morning it was around 55 degrees F first thing in the morning and on a perfectly smooth road with the radio off, I first heard this noise. It was very subtle but because this car is generally sooo quiet, I could hear it. And as I've said before, as the car warms up, the sound goes away.

[Bored of Audi]

Hi Walt,

That's the same noise as mine, but does need to be as cold, I still think it's suspension related... We have just had a new road surface it's still there but no way neer as bad as before...

[sewright]

My 2013 is doing the same thing. I will pay attention to see if it does it coming out of the garage in the morning. Definitely after it sits at work all day, it is doing it. Same behavior, it goes away within a couple miles.

[Walt White Coupe]

So it was 14 degrees F this morning and I decided to improve on the first video I posted. I deleted the first video a few posts up and replaced it with this new one. Here you can hear the sound change with speed of the car but it's still not exactly synchronized with speed. Drove the car ~ 6 miles and parked it outside for about 2 hours. Started it up and no noise again.

Part of the reason for making the video is to show the service manager when I take it in for it's last warranty service. I don't want to hear that old line, "we couldn't reproduce the problem".

[Walt White Coupe]

Sorry to be boring everyone with this:

So I brought the tire pressures up the recommended 35 psi and with temps at 28 degrees took another drive and made the video below. Not sure what was going on with the other video attempt that had a very rhythmic quality to it but this is what I've normally been hearing. It's the "rattle" over the hum of the engine.
.

[JP1906]

Unfortunately, I have the same rattle in my 640i and it disappears after 5 minutes or so. I've learned to live with it, as I can't recreate it at the dealership because the sound is gone by the time I get there.

[Walt White Coupe]

That's probably what I'll end up doing also but it goes in for it's final 4 year warranty inspection in a month or so and I intend to have them try to fix it. Will leave the car overnight so they can drive it first thing in the cold morning when the sound should be present. But since it does go away once the car warms up, I don't think it's anything serious.

[Joe Baseball]

Walt - good luck with your dealer and I really hope the two of you do find out what the rattle is about. I have a 2013 650i Xdrive that I purchased new. The rattle you describe has been with this car from the get go...two dealerships have actually experienced it over the years, neither has been able to determine its source. Just to add more confusion to a confusing situation I believe it is not just a cold weather rattle, though cold weather does enhance it and make it more noticeable. I live in Ohio and my residential street is brick pavers. There are plenty of times in the heat of summer when the engine has been running for a long time that I can hear the same rattle as I drive over the pavers, particularly driving at a low speed. So how is that for confusion? The good news, in the nearly 4 years I have owned the car nothing has happened which is traceable to the rattle. In fact, the car has been outstanding through 45,000 miles, the only warranty work, other than factory required stuff, being a battery replacement and the replacement of the seating brackets for the driver seats due to annoying squeaking. Really the only thing that bothers me about the rattle these days is that some day I may need to explain it to someone if I sell the car! But I still have a bit of warranty time left and if you are able to source the rattle I will definitely have my car checked out as well, so please stay with it and maybe you can solve one of the crazy mysteries of this car!!

[Bored of Audi]

has everybody got variable dampers??

[Walt White Coupe]

I believe in 2013 it's called "variable damper control". Yes

And that's one of the controls that I cycled through when this knocking was obvious and that change made no difference in the sound.

[nealsil]

Originally Posted by Walt White Coupe

I believe in 2013 it's called "variable damper control". Yes

And that's one of the controls that I cycled through when this knocking was obvious and that change made no difference in the sound.

What are variable dampers and how are they controlled?

Here is a clip of the noise in my '13 650x:

https://www.dropbox.com/s/js87b2zbvr8e6dz/IMG_0999.MOV?dl=0

[Walt White Coupe]

Basically they are the shock absorbers. The stiffness of a variable shock absorber is adjustable by changing drive settings i.e. sport, comfort etc. Google: Magnetic ride control

Your recorded audio is very good. I downloaded the file, cut the video out since it really didn't show much and just added to the file size, cut out the middle of the audio that was not useful and then looped the audio one time to make a 1 minute file. Anyone with this problem could download the small audio file (379 KB) and use it when describing the problem to a BMW service manger and it's small enough that it could be emailed to anyone by standard email. Here is that file and you have to download it to hear it:

https://www.dropbox.com/s/m2b7rmd8ze...0File.wma?dl=0

[Bored of Audi]

that clip is brilliant and spot on with my uk 640d with VDC... thank you as I will use that as I have had difficulty getting it clear enough on playback.

I don't know exactly how the VDC works.. is it motorised or thermal ? I use on a particular application (controlling a needle in a valve seat to control flow) were we use a fluid which changes volume extremely quickly and controlled using thyristors heaters and wondered if VDC was the same and therefore taking time to warm up as you all say within a mile or two its gone ... l

[Walt White Coupe]

My Corvette also has shocks that are adjusted by the driving setting and I'm pretty certain that BMW uses the same system. Again just google: Magnetic Ride Control.
That's Corvette terminology. Shock fluid viscosity is varied by applying an electrical charge to the fluid that contains small magnetic particles.

[Walt White Coupe]

One more observation.

So there's no doubt that the colder it is outside the more observable the "knocking" is. And as the car warms up it seems to go away.

So the car's warmed up and it's 45 degrees outside. I'm in a parking garage that, when it was constructed, the cement surface was made with a rough washboard texture with little parallel ridges. Car should be quiet but you can hear that knocking as you drive over it at 10 mph.

So I'm pretty much convinced that it's definitely something in the front, probably right, suspension.

[Walt White Coupe]

So the car is in for it's final 4th year warranty service. I gave the service manager the sound clip of the "rattle" and the car is sitting overnight outside at the dealer with temps going into the low 20's overnight. Hopefully they are at least going to acknowledge that a problem exits even if they can't solve it. Although I have very little faith that they will, I'll keep my fingers crossed. I gave it to them as a sort of challenge that no other dealer has been able to solve so far and that they would be helping a lot of 6 series owners since the rattle seems rather common. The service manager agreed that the owner of $100K BMW should not have to "live with" something like this. We shall see.