F30POST
F30POST
2012-2015 BMW 3-Series and 4-Series Forum
BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read
BMW 3-Series and 4-Series Forum (F30 / F32) | F30POST > Technical Forums > N20, N26, B46, B48 Turbo Engine / Drivetrain / Exhaust Modifications > Humming noise under slight acceleration
ARMA SPEED
Post Reply
 
Thread Tools Search this Thread
      02-13-2020, 04:50 AM   #1
butala
Registered
1
Rep
4
Posts

Drives: 320i
Join Date: Jun 2019
Location: Viet Nam

iTrader: (0)

Humming noise under slight acceleration

Dear,

My BMW F30 N20 with 40k mil has problem, it has humming noise come from font of the car under slight acceleration, rev from 1100-1450. if rev over 1500 noise gone, or left off throttle, or hard push throttle for trans downshift and rev will up over 1500 -> noise gone.

It happend in comfort and eco mode, sport mode rev allway over 1800rpm so no noise.

I do some but no help:
- All coil and spark plug
- Presure converter and vaccum pump
- Trans fuil and fillter.
- Engine oil and fillter.
- Check CP but no crank, no leak. Air fillter and intake cleaner with no leak.

Can any one give me advise or has problem like that know how to fix.

Sorry for my english.

Thanks.
Appreciate 0
      02-13-2020, 08:23 PM   #2
DoiyaSan
Noob
DoiyaSan's Avatar
United_States
2
Rep
13
Posts

Drives: F30 320i xdrive
Join Date: Feb 2020
Location: New York, USA

iTrader: (0)

I believe it is the "engine lugging", which happens when the car shifts to a higher gear but with low RPM. The engine is producing energy which cannot be transmitted to the wheels so the energy will be converted to heat and vibration, hence the "humming" you are hearing and feeling on the steering wheel. It is bad for the engine for sure.

It is possible than on D mode your car shifts to 8th gear and stays there with low RPM (1300 ish ) for good fuel economy, but causing the engine lugging. I personally also have this issue, and the lugging is worse when going uphil with light throttle, the car simply doesn't want to downshift. Very annoying.

Do you also have a engine tune? If so then it makes it worse because a tune would increase the low-end torque, making the TCU even lazier to downshift.
Appreciate 1
anotheran389.00
      02-13-2020, 09:38 PM   #3
butala
Registered
1
Rep
4
Posts

Drives: 320i
Join Date: Jun 2019
Location: Viet Nam

iTrader: (0)

Quote:
Originally Posted by DoiyaSan View Post
I believe it is the "engine lugging", which happens when the car shifts to a higher gear but with low RPM. The engine is producing energy which cannot be transmitted to the wheels so the energy will be converted to heat and vibration, hence the "humming" you are hearing and feeling on the steering wheel. It is bad for the engine for sure.

It is possible than on D mode your car shifts to 8th gear and stays there with low RPM (1300 ish ) for good fuel economy, but causing the engine lugging. I personally also have this issue, and the lugging is worse when going uphil with light throttle, the car simply doesn't want to downshift. Very annoying.

Do you also have a engine tune? If so then it makes it worse because a tune would increase the low-end torque, making the TCU even lazier to downshift.
Thanks,

No I don't have engine tune. So what is solution for it? I don't shiftpad on steering so if want down shift is very complicate. If go to sport mode is not comfort when I allway go on street not highway.
Appreciate 0
      02-14-2020, 07:41 AM   #4
DoiyaSan
Noob
DoiyaSan's Avatar
United_States
2
Rep
13
Posts

Drives: F30 320i xdrive
Join Date: Feb 2020
Location: New York, USA

iTrader: (0)

Unfortuantely I don't know of any solution... how about driving in comfort/S instead of comfort D?
Appreciate 0
      02-15-2020, 08:48 PM   #5
anotheran
Sedan Driver
Canada
389
Rep
1,018
Posts

Drives: A nice car
Join Date: May 2016
Location: Canada

iTrader: (0)

Quote:
Originally Posted by DoiyaSan View Post
Unfortuantely I don't know of any solution... how about driving in comfort/S instead of comfort D?
Or try driving in sports throttle. Keeps the gears lower.
__________________
Slapping on M Performance parts, ZHP, badges, and stickers does not ///M car make

ZCP | ZHP | ZTR | ZE0 | MSport | ZMP | DHP | MStickerPack | THP | MPPSK | MPPK
BMW MSP Lightweight Jacket | DTM Motorsport Team Cap| BMW M Drift Cat 5 | BMW M Thermo Mug
Appreciate 0
      02-17-2020, 02:09 AM   #6
butala
Registered
1
Rep
4
Posts

Drives: 320i
Join Date: Jun 2019
Location: Viet Nam

iTrader: (0)

Quote:
Originally Posted by DoiyaSan View Post
Unfortuantely I don't know of any solution... how about driving in comfort/S instead of comfort D?
Thanks, but i think must be something wrong with it. In 3 fist year, I don't hear this noise. So it make it not like bmw, comfort not but not comfort
Appreciate 0
      10-14-2020, 05:14 PM   #7
MemphisM5
New Member
MemphisM5's Avatar
3
Rep
29
Posts

Drives: BMW 328i
Join Date: May 2015
Location: DE

iTrader: (0)

Quote:
Originally Posted by DoiyaSan View Post
I believe it is the "engine lugging", which happens when the car shifts to a higher gear but with low RPM. The engine is producing energy which cannot be transmitted to the wheels so the energy will be converted to heat and vibration, hence the "humming" you are hearing and feeling on the steering wheel. It is bad for the engine for sure.

It is possible than on D mode your car shifts to 8th gear and stays there with low RPM (1300 ish ) for good fuel economy, but causing the engine lugging. I personally also have this issue, and the lugging is worse when going uphil with light throttle, the car simply doesn't want to downshift. Very annoying.

Do you also have a engine tune? If so then it makes it worse because a tune would increase the low-end torque, making the TCU even lazier to downshift.
I've got same behavior on N26 after Stage 1 tune. 1100-1200 rpm on high gears and under load are absolutely annoying. My tuner didn't find anything, which can help to avoid this, changed maps, but still got the same. But tune gives a lot of power, dyno shows upto 300hp and 450nm of torque and car runs amazingly.
Appreciate 0
      07-02-2021, 08:22 PM   #8
bloodqq
New Member
3
Rep
6
Posts

Drives: BMW 428XI
Join Date: Apr 2020
Location: Taiwan

iTrader: (0)

i’ve got this problem too. When cruising in city(6th gear) or highway(8th gear) under 1500rpm the drone come, it’s really annoying. At first I though maybe xhp will solve the problem ,but after dig some post it’s seems to be worse after tuning?
Appreciate 0
      10-10-2021, 04:20 PM   #9
Ab1234
New Member
England
0
Rep
18
Posts

Drives: 320d
Join Date: Sep 2020
Location: Norwich

iTrader: (0)

I have the exact same problem with my f30, only happens when cruising at 25-35mph, the engine is at 1100 rpm and refuses to downshift until I accelerate harder. Any solutions?
Appreciate 0
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 07:07 AM.




f30post
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST