Thought I slung a CV joint or transaxle in the rear

[Hammmerhead]

Didn't use launch mode, just in M2 mode. Revs to 2K and then WOT. Either the shift to 2nd or 3rd a loud clicking started happening that sounded like it was coming from the drivers side rear. Very loud clicking like a spring loaded gear passing over another but not locking in. I felt kind of sick for about 10 seconds thinking I was calling a tow truck with just 3K on the odometer. I let completely off the gas and it went away almost immediately and all felt normal. So is this a break in nanny the krauts setup to scare the heck out of you for running one hard with just 3K miles on it?

I just unplugged the ASD last night, but pretty certain this was a rear differential issue. I don't take anything for granted as complex as these things are now.

Anyone experienced this?

[xueju1121]

Originally Posted by Hammmerhead

Didn't use launch mode, just in M2 mode. Revs to 2K and then WOT. Either the shift to 2nd or 3rd a loud clicking started happening that sounded like it was coming from the drivers side rear. Very loud clicking like a spring loaded gear passing over another but not locking in. I felt kind of sick for about 10 seconds thinking I was calling a tow truck with just 3K on the odometer. I let completely off the gas and it went away almost immediately and all felt normal. So is this a break in nanny the krauts setup to scare the heck out of you for running one hard with just 3K miles on it?

I just unplugged the ASD last night, but pretty certain this was a rear differential issue. I don't take anything for granted as complex as these things are now.

Anyone experienced this?

Sounds strange to me. I believe most of us can hear clicking noise from front suspension, not rear.

I suggest you keep on driving normally and if it happens again, call your dealer and get it fixed. It is under warranty so no worries.

[Hammmerhead]

Originally Posted by xueju1121

Sounds strange to me. I believe most of us can hear clicking noise from front suspension, not rear.

I suggest you keep on driving normally and if it happens again, call your dealer and get it fixed. It is under warranty so no worries.

I don't know. This wasn't a sporadic clicking, it was timed and in motion and it was loud enough to be heard echoing from the pavement with the windows up and heard loudly through the cabin. I have lunched a a couple of porsche rear ends and I honestly thought I lost an axle or a tooth on a ring gear. Man these things have a lot of torque.

[xueju1121]

Originally Posted by Hammmerhead

I don't know. This wasn't a sporadic clicking, it was timed and in motion and it was loud enough to be hear echoing from the pavement with the windows up and heard loudly through the cabin. I have lunched a a couple of porsche rear ends and I honestly thought I lost an axle or a tooth on a ring gear. Man these things have a lot of torque.

Damn, if that's the case then you should definitely have it checked at dealer ASAP.

[Hammmerhead]

Originally Posted by xueju1121

Damn, if that's the case then you should definitely have it checked at dealer ASAP.

Well, Im putting about 4 hours drive time on it tomorrow. We will see how it acts.
There is so much computerized engagements going with the drivetrain, I was wondering if it may have been the rear locker trying to disengage or possibly in-between. Im scratching my head. No grease or oil around rear shafts thank goodness. It all looks ok, but man it didn't sound good after the shift or two after the dig. These things are so violent coming out of the hole it sounded like permanent damage and not something that would just "go away." I can't image having a tune and spinning all four like I read about guys doing here, but it does make me feel a little better that maybe it was something electronic in the diff. and these things are pretty durable.

[xueju1121]

Originally Posted by Hammmerhead

Well, Im putting about 4 hours drive time on it tomorrow. We will see how it acts.
There is so much computerized engagements going with the drivetrain, I was wondering if it may have been the rear locker trying to disengage or possibly in-between. Im scratching my head. No grease or oil around rear shafts thank goodness. It all looks ok, but man it didn't sound good after the shift or two after the dig. These things are so violent coming out of the hole it sounded like permanent damage and not something that would just "go away." I can't image having a tune and spinning all four like I read about guys doing here, but it does make me feel a little better that maybe it was something electronic in the diff. and these things are pretty durable.

Speaking of durability, F85 has a stainless steel drive shaft, the most heavy and robust one in current M line up.

[onfireX5]

I would use LC and retest. Best way to know if something broke.

[amhtsai]

I have the same issue. I'm trying to record the sound and take it to the dealer and play it to them. Doesn't happen all the time. The first time it happened, I thought I broke something. I tried closing the sun roof cover to see if it was a rattle, but it wasn't.

[Hammmerhead]

Originally Posted by onfireX5

I would use LC and retest. Best way to know if something broke.

Ha! I haven't even read the procedure for LC yet. I hope its simple

[Alan l.]

Did you have the windows open and the sunroof visor open?

Theres a few threads on there where people noticed a loud clicking sound coming from the back under WOT. I've heard this on my X5 35i with the windows open and sunroof cover open but sunroof closed. Some mentioned it was the sunroof drain covers flapping.

Alan

[Hammmerhead]

Originally Posted by Alan l.

Did you have the windows open and the sunroof visor open?

Theres a few threads on there where people noticed a loud clicking sound coming from the back under WOT. I've heard this on my X5 35i with the windows open and sunroof cover open but sunroof closed. Some mentioned it was the sunroof drain covers flapping.

Alan

I may have had the roof tilted up but wasn't open, but I can't remember for sure.

I would be shocked if it was something flapping in the wind. This sounded pretty serious and mechanical to my ears.

Had no troubles today, but didn't do any hammering from a dig. I went in to eat lunch, came back out and my heads up display was gone. Checked the settings and it was still on. Turned it off, turned it on and no help. Went to pick up my little boy after an hour drive, fired it up and it came back on. Surely they got most of the '15 bugs handled for '16, but I now have another mystery to add to the list.

[dkhm3]

is this the wheel bearing issue again?

like on this video @ 40 sec?

[LCI550M]

Originally Posted by Hammmerhead

I may have had the roof tilted up but wasn't open, but I can't remember for sure.

I would be shocked if it was something flapping in the wind. This sounded pretty serious and mechanical to my ears.

Had no troubles today, but didn't do any hammering from a dig. I went in to eat lunch, came back out and my heads up display was gone. Checked the settings and it was still on. Turned it off, turned it on and no help. Went to pick up my little boy after an hour drive, fired it up and it came back on. Surely they got most of the '15 bugs handled for '16, but I now have another mystery to add to the list.

Pretty sure its the sunroof. I've heard the same exact loud flapping sound before on my X5. Scared the hell out of me the first time i've heard it. Its all the air rushing into the roof area due to your windows being open but it has no where to go. Something is def. moving around up there.

Try opening your car windows down, open the sun roof cover but don't open the sunroof. Then romp on the gas from 0-40 and you should be able to reproduce the sound.

Joe

[Hammmerhead]

Originally Posted by LCI550M

Pretty sure its the sunroof. I've heard the same exact loud flapping sound before on my X5. Scared the hell out of me the first time i've heard it. Its all the air rushing into the roof area due to your windows being open but it has no where to go. Something is def. moving around up there.

Try opening your car windows down, open the sun roof cover but don't open the sunroof. Then romp on the gas from 0-40 and you should be able to reproduce the sound.

Joe

It sure would be nice if it was something like this. The best way I can describe it is like putting a poker card in the spokes of a bicycle when you were a kid only a LOT louder. Or if you attached a piece of sheet metal to the tread of a tire somehow. It was knock, knock, knock, knock only a loud clicking sound that seemed to match the revolutions of the drivetrain.

I did have a couple of friends with me when it happened and they were like WTF did we just lunch in the rear of this thing. I let off the gas and slowed and it disappeared. Very strange.

[Alan l.]

Originally Posted by Hammmerhead

The best way I can describe it is like putting a poker card in the spokes of a bicycle when you were a kid only a LOT louder. .

This is exactly how it sounded in my car.

[Hammmerhead]

Originally Posted by Alan l.

This is exactly how it sounded in my car.

Thats just weird. I would like to know where the sounds is coming from. I also thought its might be a solenoid going haywire on either of the exhaust flaps. You can't tell me test mules didn't have this happen at least once. Think about all the magazine and car tests where you get quite a few "staff" members spending the majority of the day thrashing and launching these things. If we are having it happen, surely the powers that be have too.

[Alextacy]

Its not mechanical at all which is good, still hard to pinpoint though.
There is another thread about it here.
http://f15.bimmerpost.com/forums/sho....php?t=1186607

[r33_RGSport]

Do you have aftermarket wheels with aftermarket lug bolts?
My suspicion is the rear lug bolt is too long and hitting the e-brake spring system.

[Hammmerhead]

Originally Posted by r33_RGSport

Do you have aftermarket wheels with aftermarket lug bolts?
My suspicion is the rear lug bolt is too long and hitting the e-brake spring system.

No. totally stock. Thanks for the mention though

[onfireX5]

Close all of the windows and retest to verify.

Find a safe spot. You don't need LC to test.

Leave the trans in auto mode. Hold the footbrake down hard, put the accel to the floor, tach should go to 2700 rpm, let off the footbrake and let it shift a few time and see if the noise is still there......only way to tell.

[onfireX5]

If you ever want to try LC :
Launch Control Function: Launch Control enables optimal acceleration when driving off on a dry roadway.

Sequence Precondition/Action

1.The vehicle must be stationary, the engine running and at operating temperature (approx. 10 km / 6 mile warm-up journey)

2. Dynamic Stability Control is deactivated or M Dynamic Mode is activated.

3. The Sequential mode and the third Drivelogic driving program are selected.

4. The brake pedal is gently pressed with the left foot and held.

5. The accelerator pedal is depressed fully and held in this position.

6. In the M instrument cluster a flag symbol must appear (if not, check notes and steps 1-5).

7. An optimum engine speed for pulling away is adjusted.

8. The left foot is taken off the brake within 5 seconds.