12-21-2015, 10:16 PM | #1 |
The Schwab
474
Rep 1,605
Posts
Drives: 2020 AW M340xi
Join Date: Jun 2011
Location: Chicagoland
|
Faint High Pitched Noise - Highway Driving
I have a 16 M235xi 8AT, and having just taken an 800 mile road trip I noticed something. When I am cruising at highway speed (~75mph), and I let off the gas, I hear a faint high pitched noise. When I get back on the gas it goes away, but then when I let off I hear it again.
Was wondering if anyone else has heard this as well, and if its anything to be concerned with. I am thinking it may have something to do with the whole efficient dynamics, but I am not too sure really. Keep in mind, this is only when I have my music off, so its definitely something you have to try to hear. Anyone heard this? |
12-22-2015, 06:00 AM | #3 | |
The Schwab
474
Rep 1,605
Posts
Drives: 2020 AW M340xi
Join Date: Jun 2011
Location: Chicagoland
|
Quote:
|
|
Appreciate
0
|
12-22-2015, 06:07 AM | #4 |
Major General
3081
Rep 5,580
Posts |
When u let off the throttle you create vacuum from the sudden reduction of exhaust force and the turbo slowing.
As much as a turbo makes noise when it's winding-up and blowing off excessive pressure it also creates high-pitch noise from reduction of pressure and flow. |
Appreciate
3
|
12-25-2015, 07:46 PM | #5 |
First Lieutenant
113
Rep 303
Posts |
very much like what I have w/ aftermarket intake. Except I hear this every time I let off the gas pedal.
__________________
2020 M4 Heritage Edition///Velvet Blue
|
Appreciate
0
|
12-25-2015, 09:30 PM | #6 |
Second Lieutenant
61
Rep 273
Posts |
heh. I get to hear a faint whine related to speed (NOT rpms NOT acceleration) starting at about 20mph... like a plane taking off ... I think... a whine... anyone hear that?
__________________
//M235ix Alpine White
|
Appreciate
0
|
02-19-2016, 11:43 AM | #7 |
Ballin' out of control.
521
Rep 1,289
Posts |
F2x and F3x cars have an issue with a high-pitched noise coming from the center A/C vents which can be difficult to duplicate. Ask your dealer to refer to SI B64 09 15. They need to install a parts kit.
__________________
Alpina B3 Flash/BMS OCC/ER CP/ETS 5/HKS BOV/M3 Control Arms
|
Appreciate
0
|
02-19-2016, 11:48 AM | #8 |
The Schwab
474
Rep 1,605
Posts
Drives: 2020 AW M340xi
Join Date: Jun 2011
Location: Chicagoland
|
|
Appreciate
0
|
02-19-2016, 11:53 AM | #9 |
Ballin' out of control.
521
Rep 1,289
Posts |
__________________
Alpina B3 Flash/BMS OCC/ER CP/ETS 5/HKS BOV/M3 Control Arms
|
Appreciate
0
|
Post Reply |
Bookmarks |
|
|