BMW
X1 / X2
BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read
BMW X1 (F48) and X2 (F39) Forums General BMW X2 Forum (F39) high pitched whistle when accelerating lightly

Post Reply
 
Thread Tools Search this Thread
      10-30-2019, 04:52 PM   #1
satz
Lieutenant Colonel
Australia
333
Rep
1,642
Posts

Drives: 2019 BMW X3 M40i
Join Date: Dec 2014
Location: A land down under

iTrader: (0)

high pitched whistle when accelerating lightly

Hi all
Mine's the 2.0 petrol turbo with only 6,000 km on the clock.

is it normal to hear a high-pitched whistle (almost like the wastegate sound except without fluttering) while accelerating?

I can hear this in underground carparks and even on the open road at low speed with window down. When I release the accelerator the sound stops , and then i hear the wastegate flutter...

I never had this on other turbo cars, even on older BMW twin turbo E90.

Could it be a problem or is that normal on the newer B48 engines?

cheers
__________________
2019 X3 M40i, Sophisto grey, H/K, pano
Previous: 2019 BMW X2 Msport, Mineral Grey, Adaptive Suspension, H/K
Previous: 2009 335i LCI, Bluewater
Appreciate 0
      10-31-2019, 01:12 PM   #2
rice_rocket88
Major
No_Country
295
Rep
1,076
Posts

Drives: E60 F48 F39
Join Date: Mar 2019
Location: Boston

iTrader: (0)

You couldn't hear turbo spool on your e90?!?
Appreciate 0
      10-31-2019, 04:10 PM   #3
satz
Lieutenant Colonel
Australia
333
Rep
1,642
Posts

Drives: 2019 BMW X3 M40i
Join Date: Dec 2014
Location: A land down under

iTrader: (0)

nowhere near as obvious as on the X2. Also it doesn't seem to make the sound when the engine's fully warmed up...
__________________
2019 X3 M40i, Sophisto grey, H/K, pano
Previous: 2019 BMW X2 Msport, Mineral Grey, Adaptive Suspension, H/K
Previous: 2009 335i LCI, Bluewater
Appreciate 0
      10-31-2019, 08:04 PM   #4
rice_rocket88
Major
No_Country
295
Rep
1,076
Posts

Drives: E60 F48 F39
Join Date: Mar 2019
Location: Boston

iTrader: (0)

Hmm I'm not sure what to say if the sound goes away when it's warm.

On all my turbo cars as long as it's quiet enough and on places where it can echo (ie carparks.. tunnels, when driving beside concrete barriers). I can hear the spool very well. If it is also followed by a wastegate/BOV/BPV sound it's really all there is to say about it. The only other thing I could think of is simply the air sucking in the intake noise? It might sound louder when the car is colder because the air is more dense vs when the engine is warmed up it's not so much? Also the cold start increases idle and fuel mixture.
Appreciate 0
      10-31-2019, 11:13 PM   #5
strripedz
Enlisted Member
5
Rep
44
Posts

Drives: X2 F39
Join Date: Nov 2018
Location: Melbourne

iTrader: (0)

I definitely agree with rr.
I could hear the hissing noise, but its only when the car hits the boost (around 3k rpm and above).
Then it is followed by BOV once I let the throttle go at higher rpm range.
That being said, the noise is consistent throughout the temperature doesn't matter if its cold or warm engine.
Appreciate 0
      10-31-2019, 11:25 PM   #6
satz
Lieutenant Colonel
Australia
333
Rep
1,642
Posts

Drives: 2019 BMW X3 M40i
Join Date: Dec 2014
Location: A land down under

iTrader: (0)

I'll keep testing (I'm lucky to park at work in a large basement carpark).

But I'm sure I only hear the high pitched whistle on acceleration when cold, not hot.

The BOV flutter I hear as soon as I release the throttle, regardless of engine temp.

I'm just trying to see if this has any relation to my strong 'lag' when I accelerate from standstill. It's really bad until about 3000rpm then it kicks in with steering wheel tug, etc! Like a damn 1980s turbo. Even worse when AC is on.

This problem is really only there after the engine is warm, esp if the car has been parked for a say 20 minutes when hot, and then redriven.

Striped - is yours anything like that, or is the acceleration reasonably even from standstill? Even with AC on?

cheers
__________________
2019 X3 M40i, Sophisto grey, H/K, pano
Previous: 2019 BMW X2 Msport, Mineral Grey, Adaptive Suspension, H/K
Previous: 2009 335i LCI, Bluewater
Appreciate 0
      11-03-2019, 04:28 PM   #7
strripedz
Enlisted Member
5
Rep
44
Posts

Drives: X2 F39
Join Date: Nov 2018
Location: Melbourne

iTrader: (0)

Interesting, Im curious now since you mentioned about accelerating with and without AC.
Unfortunately, I haven't tested that, but I will let you know how it goes.

As for the lag, yeah, not a single doubt.
Hows your BMS Pedal Tuner though? Does it help?
Appreciate 0
      11-03-2019, 05:49 PM   #8
satz
Lieutenant Colonel
Australia
333
Rep
1,642
Posts

Drives: 2019 BMW X3 M40i
Join Date: Dec 2014
Location: A land down under

iTrader: (0)

If it's the lag, it puzzles me why it's relatively okay when engine's cold, but not good when engine's hot. Seems like heat-soak I had in an older turbo car that had a top mount intercooler.

The BMS pedal tuner definetely helps with responsiveness and being able to 'throttle steer'... But doesn't help in the lag from takeoff. Still worth doing.

cheers
__________________
2019 X3 M40i, Sophisto grey, H/K, pano
Previous: 2019 BMW X2 Msport, Mineral Grey, Adaptive Suspension, H/K
Previous: 2009 335i LCI, Bluewater
Appreciate 0
      11-04-2019, 02:49 PM   #9
billnchristy
Major
1579
Rep
1,479
Posts

Drives: 2022 M440xi GC
Join Date: Feb 2019
Location: Atlanta

iTrader: (0)

Garage List
Non M35i don’t have bov. It’s in the engine tech manual
Appreciate 0
      11-04-2019, 07:22 PM   #10
//TMT
Lieutenant
//TMT's Avatar
United_States
129
Rep
419
Posts

Drives: 2020 X2 M35i, 2005 Volvo V50T5
Join Date: Sep 2019
Location: Eastern Massachusetts

iTrader: (0)

Speaking of the engine tech manual, I think this section explains the noise. It's a consequence of the design, to enable the catalytic converter to come up to operating temperature quickly, achieving the desired emissions certification.

I added some emphasis.

Quote:
Catalytic converter heating

When starting the combustion engine from cold, the wastegate valve is opened as wide as possible and the ignition point is adjusted to retard. The retarded ignition point delays the combustion process which in turn supports the heat input for heating of the catalytic converter. As the turbine housing is short , it has been possible to position the catalytic converter very close to the wastegate valve. As the exhaust gas flows into the catalytic converter at the perfect angle and because of its position close to the engine, the catalytic converter reaches its operating temperature very quickly. If the wastegate valve is opened when cold, pulsation of the exhaust gas may cause vibrations in the wastegate valve, which are perceived as noise. This is not due to a defective component, and is normal running noise. This noise becomes less audible as the temperature of the component increases.
Appreciate 0
      11-04-2019, 09:45 PM   #11
satz
Lieutenant Colonel
Australia
333
Rep
1,642
Posts

Drives: 2019 BMW X3 M40i
Join Date: Dec 2014
Location: A land down under

iTrader: (0)

Can we find the Engine Tech Manual online? I'd love to reference it for other aspects. e.g. the difference between US Market 2.0 petrol turbo (169kw) and the rest of the world 2.0 petrol turbo (141kw).

thank you
__________________
2019 X3 M40i, Sophisto grey, H/K, pano
Previous: 2019 BMW X2 Msport, Mineral Grey, Adaptive Suspension, H/K
Previous: 2009 335i LCI, Bluewater
Appreciate 0
      11-04-2019, 10:52 PM   #12
satz
Lieutenant Colonel
Australia
333
Rep
1,642
Posts

Drives: 2019 BMW X3 M40i
Join Date: Dec 2014
Location: A land down under

iTrader: (0)

I listened to my engine sound again, and perhaps it's more a high-pitched 'hiss' rather than a whistle, which is why I didn't think it was the turbo whine.

It definitely releases a 'flutter' noise when I lift off the throttle suddenly.
__________________
2019 X3 M40i, Sophisto grey, H/K, pano
Previous: 2019 BMW X2 Msport, Mineral Grey, Adaptive Suspension, H/K
Previous: 2009 335i LCI, Bluewater
Appreciate 0
      11-05-2019, 05:08 AM   #13
billnchristy
Major
1579
Rep
1,479
Posts

Drives: 2022 M440xi GC
Join Date: Feb 2019
Location: Atlanta

iTrader: (0)

Garage List
https://www.bimmerpost.com/goodiesforyou/B46-Engine.pdf
Appreciate 0
      11-05-2019, 05:27 AM   #14
Beagler
First Lieutenant
United Kingdom
75
Rep
383
Posts

Drives: Sept 2019 Facelift X1 MSPORT
Join Date: May 2019
Location: Lancashire

iTrader: (0)

Quote:
Originally Posted by billnchristy View Post
Is there a similar document for the B48c engine or is this the same.
__________________
Everthing goes to Entropy in this Age.
Appreciate 0
      11-05-2019, 07:35 AM   #15
//TMT
Lieutenant
//TMT's Avatar
United_States
129
Rep
419
Posts

Drives: 2020 X2 M35i, 2005 Volvo V50T5
Join Date: Sep 2019
Location: Eastern Massachusetts

iTrader: (0)

Quote:
Originally Posted by Beagler View Post
Is there a similar document for the B48c engine or is this the same.
There does not appear to be any update available to us, but I'm sure it exists. Let us know if you find it first!
Appreciate 0
      11-05-2019, 07:40 AM   #16
//TMT
Lieutenant
//TMT's Avatar
United_States
129
Rep
419
Posts

Drives: 2020 X2 M35i, 2005 Volvo V50T5
Join Date: Sep 2019
Location: Eastern Massachusetts

iTrader: (0)

Quote:
Originally Posted by satz View Post
It definitely releases a 'flutter' noise when I lift off the throttle suddenly.
Do you mean lifting off when still in the carpark? That's probably just manifold vacuum rippling through various nooks and crannies. With the wastegate open for warmup, and no real load to call for boost anyway, it isn't from there.

Lifting off on the road is another matter. There, it's the wastegate opening, which changes the exhaust flow direction, and also the blowoff opening, which causes the boost to recirculate round'n'round until flushed through the engine.
Appreciate 0
      11-06-2019, 06:16 PM   #17
satz
Lieutenant Colonel
Australia
333
Rep
1,642
Posts

Drives: 2019 BMW X3 M40i
Join Date: Dec 2014
Location: A land down under

iTrader: (0)

Many thanks Bill!
__________________
2019 X3 M40i, Sophisto grey, H/K, pano
Previous: 2019 BMW X2 Msport, Mineral Grey, Adaptive Suspension, H/K
Previous: 2009 335i LCI, Bluewater
Appreciate 0
      11-06-2019, 06:21 PM   #18
satz
Lieutenant Colonel
Australia
333
Rep
1,642
Posts

Drives: 2019 BMW X3 M40i
Join Date: Dec 2014
Location: A land down under

iTrader: (0)

Quote:
Originally Posted by Beagler View Post
Is there a similar document for the B48c engine or is this the same.

I don't think the US has the B48C engine. Seems to be the rest of the world that has to put up with the lower power engine (141kW).

I've been trying to research the physical differences between the US market 2.0 petrol turbo and the rest of the world version

Beagler- were you able to find your engine number stamping on the actual engine block? I had a quick look under the hood but I think too much ducting blocks the view of that area...

My paperwork quotes a totally different engine number. IIRC something beginning with W but ending in ...K041

cheers
S
__________________
2019 X3 M40i, Sophisto grey, H/K, pano
Previous: 2019 BMW X2 Msport, Mineral Grey, Adaptive Suspension, H/K
Previous: 2009 335i LCI, Bluewater
Appreciate 0
      11-06-2019, 07:14 PM   #19
satz
Lieutenant Colonel
Australia
333
Rep
1,642
Posts

Drives: 2019 BMW X3 M40i
Join Date: Dec 2014
Location: A land down under

iTrader: (0)

Quote:
Originally Posted by //TMT View Post
Do you mean lifting off when still in the carpark? That's probably just manifold vacuum rippling through various nooks and crannies. With the wastegate open for warmup, and no real load to call for boost anyway, it isn't from there.

Lifting off on the road is another matter. There, it's the wastegate opening, which changes the exhaust flow direction, and also the blowoff opening, which causes the boost to recirculate round'n'round until flushed through the engine.

hi TNT, I can accept the wastegate sound (though it's def louder than my old twin turbo 335i), but it's the high pitched 'hiss' when accelerating (before lifting off throttle) that's interesting. I can hear this when driving in the open as well (when my window's open)...

cheers
__________________
2019 X3 M40i, Sophisto grey, H/K, pano
Previous: 2019 BMW X2 Msport, Mineral Grey, Adaptive Suspension, H/K
Previous: 2009 335i LCI, Bluewater
Appreciate 0
      11-07-2019, 09:05 AM   #20
billnchristy
Major
1579
Rep
1,479
Posts

Drives: 2022 M440xi GC
Join Date: Feb 2019
Location: Atlanta

iTrader: (0)

Garage List
Realoem calls our engine b48e
Appreciate 0
      11-10-2019, 07:03 PM   #21
satz
Lieutenant Colonel
Australia
333
Rep
1,642
Posts

Drives: 2019 BMW X3 M40i
Join Date: Dec 2014
Location: A land down under

iTrader: (0)

For the 141kW 2.0 petrol turbo (non US), realoem reports the engine type as B48C.

cheers
__________________
2019 X3 M40i, Sophisto grey, H/K, pano
Previous: 2019 BMW X2 Msport, Mineral Grey, Adaptive Suspension, H/K
Previous: 2009 335i LCI, Bluewater
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 05:58 AM.




xbimmers
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