01-22-2021, 01:10 PM | #1 |
Trolling the Nürburgringroad
8
Rep 18
Posts |
Help please from M4 owners
So I just bought a 2016 M4 (DCT), 14k miles on it, good nick etc.
Before this was a 2014 640d, with the 8 speed ZF auto. Now I have noticed that, when starting up from cold, and i drive off, when it shifts into 2nd there's a bit of a rumbling sound for a second. Once it's done with that, that's it, doesn't happen again until the next cold start. And it does it almost every time, after cold start. Just wondering if this is a "characteristic" of the DCT, or should I start investigating further. Thanks |
01-22-2021, 01:16 PM | #2 |
Lieutenant
296
Rep 577
Posts |
I've also got a 2016 M4 DCT and I've never noticed anything like that on mine. The coldest weather mine has ever been in on a cold start though is around 5C.
|
Appreciate
0
|
01-22-2021, 01:25 PM | #3 | |
Captain
1121
Rep 845
Posts |
Quote:
Especially in cold weather here in canada you can hear it. After that it never happens again. Had the car 30k miles no issues, has always done it i believe it's a characteristic of the transmission when ice cold. |
|
Appreciate
0
|
01-22-2021, 01:50 PM | #4 |
Racecar Driver
1273
Rep 1,925
Posts
Drives: BMW M4
Join Date: Mar 2019
Location: Beverly Hills, California
|
From 1st to 2nd there is sometimes a clunk, it doesn't get super cold where I am though. Not a rumbling noise though.
__________________
N1rve
2019 BMW ///M4 - Alpine White | Sakhir Orange/Black Leather | M-DCT | Executive Package | 19" Black 437M Wheels | Carbon Fiber Trim | Sunroof | Active Blind Spot | Heated Steering Wheel | Adaptive M Suspension |
Appreciate
0
|
01-22-2021, 01:55 PM | #5 |
Trolling the Nürburgringroad
8
Rep 18
Posts |
Thanks guys I should probably try make a video of it, so you can hear it.
I know the clunk you speak of. Wondering if anyone knows how this particular DCT works, and what actuator makes the change or what moves to shift from 1st to 2nd? Wondering if that could be making this sound. |
Appreciate
0
|
01-22-2021, 06:08 PM | #6 |
New Member
5
Rep 19
Posts |
My car had a brief grind like noise when it was first taking off after sitting for a while. I made a thread on it a while back but never figured it out 100%, though my noise sounded like it was from the back maybe diff/fuel pump area.
https://f80.bimmerpost.com/forums/sh....php?t=1708554 I left it alone for a while until one day the dealer did a software update and I never heard the noise again. If your noise is similar its just something software/programming related I wouldn't worry especially since it just does it once at an exact point every time. |
Appreciate
0
|
01-23-2021, 06:13 AM | #7 | |
Trolling the Nürburgringroad
8
Rep 18
Posts |
Quote:
This is the sound mine makes, just after shifting into 2nd, at 0:09 |
|
Appreciate
0
|
01-23-2021, 08:53 AM | #8 |
Major General
1824
Rep 6,979
Posts
Drives: 15 F80 M3, 22 G01 X3 30i
Join Date: Apr 2010
Location: Wendell, NC
|
I have a '15 M3 with the exact same drivetrain, and no clunk from 1st to 2nd after a cold start. I always let the car warm up to the point where the fast idle slows down and the wastegates close (around 90 seconds) before driving off. I also have had the diff and M-DCT reprogrammed to GTS level, though.
__________________
2015 F80 ///M3 Sedan 7DCT Tanzanite, 2022 X3 sDrive30i 8AT Brooklyn Grey |
Appreciate
0
|
01-24-2021, 03:54 AM | #9 | |
New Member
5
Rep 19
Posts |
Quote:
You can get the update if you really want but in hindsight I dont think what I had was an issue per se. Could be a software glitch or could be something that was actually programmed but it never affected how the car drove and was not a constant noise. |
|
Appreciate
0
|
01-24-2021, 04:06 AM | #10 |
Major
555
Rep 922
Posts |
Getting a software update is also a good idea regardless, as OP has a 2016 and the software has been refined significantly over the years.
|
Appreciate
0
|
Post Reply |
Bookmarks |
Thread Tools | Search this Thread |
|
|