E46 Whistle

nicwes

///Member
I have the E46 320i. When the revs get to about 4700rpm there's a whistling sound coming from the back. gets louder the higher the revs go.

Any ideas on what causes this? :thinking:
 

nicwes

///Member
Coisman said:
:pimp:
Must be one of those rear mounted turbo's I keep hearing about :mmm:

:clap: Goeies Coisman! :thumbsup:

If only it was something to do with a turbo!
 

XMAX

///Member
As far as I know this whistle is a common thing with the e46 6 cylinders.

I don't think its a sign of trouble,

If you have the chrome tailpiece inserts, it could have something to do with that.

I also have this whistle on my E46 325i, and so does two other 6 cylinder e46 6 cylinders I've been in.

I could be wrong, and as always, if someone know better, please let us know.
 

Sankekur

///Member
When I get to around 4 -4.5k rpm I also get a whistle in my 330i but mine sounds more like its coming from the engine and sounds kinda like a supercharger whine :)
 

moranor@axis

///Member
Official Advertiser
Sankekur said:
When I get to around 4 -4.5k rpm I also get a whistle in my 330i but mine sounds more like its coming from the engine and sounds kinda like a supercharger whine :)

I get the same thing but im sure it is something to do with the flap in the tips
 

Sankekur

///Member
could be but I don't think mine has anything to do with the exhaust flap as mine is just there but doesn't do anything, but either way I don't think it is a problem unless it gets lower the faster you drive or the higher the RPM. Like I had a shot bearing on my corsa, and as the revs climbed the whine would get louder and louder until at about 120 wind noise would drown it out, sounded awesome to say the least :) (a glimpse into the mind a corsa driver) but I had it fixed after a couple of weeks.
 

ChrisBrand

Staff - Legal
Staff member
Hey guys, mine does it as well and after research found it could be the lower intake boot that wears and develops cracks. I have a full DIY and will post it tommorow as i am still writing exams tonight.
 

moranor@axis

///Member
Official Advertiser
ChrisBrand said:
Hey guys, mine does it as well and after research found it could be the lower intake boot that wears and develops cracks. I have a full DIY and will post it tommorow as i am still writing exams tonight.
awesome man i think i have a vacuum leak could be the same thing im going to investigate this when i have some time...

but the other whistling noise is from the back so dont think its related to the vacuum leak
 

BMW M

///Member
My 2c worth...

Have your Aircon gas level checked. Both the e46's I've owned developed a whinning noise when aircongas was low, starting as a low hum turning into a hellish whine as the revs go up.

Top gas up at Motolek, and presto! All is back to normal.

Happy Motoring!
 

ChrisBrand

Staff - Legal
Staff member
After seeing all of these threads on people asking why their cars are making a whistling sound at high rpm or while driving, it got me wondering what has caused this and I did some research and found that it was the lower intake boot that gets old and starts to crack, letting in unfiltered air under hard or moderate acceleration, which in turn leads to that loud whistle you may be experiencing. My car does this too so therefore I decided to fix the problem. I have made a DIY on how to do this to help fellow e46Fanatics who are experiencing this problem to fix it. Here is my DIY. Enjoy.



Difficulty: It is simple if you know your way around the engine and if you have disassembled the intake of your car before, I'd say this repair will take the average person anywhere from 45 minutes to 1 hour 30 minutes.


Parts Needed:

Tube Elbow (BMW P# 13-54-1-438-759) $12-18


Tools:

6mm, 10mm Sockets with extensions
T30 TORX Socket
6mm Wrench
3/8" Ratchet (1/4" Ratchet will help make things easier)
Needle Nose Pliers
Flat-Head Screwdriver

Instructions:

Step 1: Remove the little clamps holding together the front part of your intake. Use the needle nosed pliers to help get the clamps out.

step1-1.jpg


Step 2: Remove the first part of your intake. It should look something like this when you are done.

step2.jpg


Step 3: Remove the two bolts holding your air box in by using the 10mm socket and wrench with an extension to make it easier.

step3.jpg


Step 4: Loosen the metal band that is around the upper intake hose with the flathead screwdriver.

step4.jpg


Step 5: Disconnect the MAF (mass airflow sensor) by pressing down on the small metal bar on top of the connector and pulling the connector away.

step6.jpg


Step 6: Pull apart the uppper intake hose from the back of the MAF and once disconnected remove your entire airbox.

step7.jpg


Your engine should look like this by now.



step 7: Now its time to remove the cabin filter, you need to loosen these three clamps by pushing down and turning counter-clockwise.

step9.jpg


The clamps should pop up if you loosened them the right way.

step10.jpg


Step 8: Remove the lid of the cabin filter by lifting up and pulling it out.

step11.jpg


remove the filter also.

step12.jpg


Step 9: Now you will see 4 TORX bolts.

step13.jpg


Remove them with a T30 TORX bit.

step14.jpg


before removing the cabin filter, remove a black clip that is on the bottom of it holding some wires, just unclip it and pull the wires out.

step15.jpg


Step 10: After removing all 4 TORX bolts, remove the entire cabin filter assembly by lifting up and pulling it out.

step16.jpg


By now your engine bay should be looking something like this.

step17.jpg


Step 11: Loosen the metal bands around the bottom and top of the upper intake hose and the intake boot, also pull out the hose leading into the upper intake hose.

step18.jpg


Step 12: Remove the upper intake hose by pulling it off, you might need to pull hard to get it off, but once its off you will see the intake boot that you will be replacing. I circled one of the metal bands on the back of the small hose on the intake boot, try and loosen this the best you can and pull that hose off.

step19.jpg


You may want to remove this black wall that is near the brake booster, it gets in the way and when removed will allow you better access to the screws to loosen the metal bands around the back of the intake boot. Just remove this piece by turning both screws that I've circled and pull them out, then just lift this piece out of the way.

step20.jpg


Step 13: Feel around the back of the intake boot for the bolt on the metal band and try and see if you can see it, then loosen that and pull the intake boot off as hard as you can, its not easy to get off but eventually it will come off.

Finally got the SOB off.

step22.jpg


This is what it will look like with the intake boot removed. To install the new one just put the metal bands from the old one on the new one and push the new one on over the big hole first then push the small tube on next, make sure you put it on really secure as you don't want any air leaks which would defeat the purpose of this repair.

step21.jpg



New intake boot on!

step23-2.jpg



Now to put everything back together, just follow the steps backwards and if you did it right it should be looking like this.




Finally, check over everything and make sure nothing is loose and then close your hood and start the car, let it warm up, the idle should be a lot smoother now, go for a drive and enjoy the quiet sound of your engine minus the annoying whistle.


 
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