engine whistling under acceleration

[bmwmike]

I did a search and found some suggestions but no definitive answers or fix.

I own a 03 2.5/5spd. Ever since I've purchased the car Ive noticed a slight whistle sound under light acceleration. It seems to be a position of the pedal (like 15%) and if I hear it and press harder or lighter on the throttle it goes away. I then installed a cone filter and the noise is now amplified which I assume is just because the intake makes the engine noise louder. Is this normal for our cars? Anyone with the 2.5 or 3.0 notice the same thing, especially with an intake? I've been told it's fairly normal and put the stock air box back on.

I checked the intake tubing from the filter to the engine by taking everything apart and nothing looks cracked or split open. I carefully put everything back together making sure its all sealed with no fix. :?

edit: meant to put this in problems, could a mod move it?

 

[Yal]

I have the same issue. Replaced one split section of tube on the air intake, but that didn't fix it. The noise is really embarrassing, but I haven't had time to take it to a shop yet. I get it between 1800 and 2200 rpm mostly.

 

[cj10jeeper]

On X5 forums there are many reference to this on the 3.0i petrol (same engine) which I have researched but not yet had a time to look at on mine, where I have had this exact noise for a few months. Aside the standard cracked/loose intake hoses one recurring suggestion is the DISA valve, which if faulty causes this low whistle on light acceleration.

Someone may have more detail on it but I believe it's a £100 plus part to swap out.

 

[mystik]

im not trying to be an ignorant asshole here.. but....

for some odd reason... i have heard that it is a normal feature of our car. i think someone had made a comment about it sounding like a "turbo" and fooling all those other turbine driven cars (pls excuse my cheesy analogy). but, i may be wrong as to the noise and it indeed may be a fault in the mechanics of the car (which is not good).

in any case, this topic stands to make me wonder about this whistle due to the fact that my ride does this, too. :| :?

 

[Smokin]

My '03 325Ci whistled a bit when just starting up-I assumed it was the VANOS.


My Probe GT (Ford body,etc and Mazda mx-6 drivetrain) really whirred. Definitely sounded like a turbo and would really really scoot. I loved that car (may it rest in pieces-hit head on by a drunk driver...... )

 

[IMZ4N]

I just went through the DISA valve piece. I did not get a whistle noise from the issue. I just got the lights on the cluster. Check engine and EML light come on. What happenes to the DISA valve ( or what happened to mine) the damper ( valve ) is mounted to be able to rotate in a circular motion, meaning that the top and bottom of the damper has pins that go into two depressions in the molding and the hoop that each end of the damper rotates on. The damper fails at the top where it fits to the hoop. Mine failed away from from the opposing part of the damper. I noticed the cluster and decrease in power. The car still ran, as I was 149 miles fron the house. I have replaced the intake boot as well. Huge difference in the pick-up without downshifting., and in sport mode, all I can say is " I'm back ".

 

[Medium Dave]

My 03 3.0S makes this whistling noise. I have looked at the hoses but cannot find a crack anywhere. I'll be interested to find out if it is a fault or just a normal noise for our cars.

 

[IMZ4N]

Just a thought, My damper failed away from the housing. What if it fails in the other direction? Might create a whistle.

 

[srhutch]

Just a thought but I had a similar issue last year, turned out to be the oilf filter wasnt seated correctly, has anybody changed theres recently?

To be fair I described mine as a drive belt noise, but it's worth a look.

http://www.z4-forum.com/forum/viewtopic.php?f=3&t=1275&p=18176#p18176

http://www.z4-forum.com/forum/viewtopic.php?f=2&t=1442&p=20532&hilit=oil+filter+seated#p20532

 

[Aebous]

I also had this problem, mine turned out to be a cracked hose, look real closely at your vacuum hoses, the slightest crack will do it. Some people attribute it to a "ghost whistle", but as another forum member said way back when, it's not normal, take it to get fixed.
http://www.z4-forum.com/forum/viewtopic.php?f=3&t=5592
http://www.z4-forum.com/forum/viewtopic.php?f=3&t=3939

Mine was significantly reduced after I changed that part. I can barely hear it now, and then only when going slow with the radio real low. Of course though, that part I pictured was indeed cracked, don't go changing it if it isn't

 

[z200]

i have the same pro around a week now i will goi to my dealer and check the part no 5 and i will l;et you know

 

[Aebous]

I guess it's too long for me to say I'm updating. I didn't feel what I'm going to say deserved a new thread...
At any rate I'm bumping. My previous statement is still true and so begins my story.

I was creeping up on 3k left till Inspection II time and dreading every moment. The other day I decided to go get it done (i'm out of warrenty). I told the dealer feller about my ghost whistle and a suspected vacuum leak and also that the engine sounded rough like it needed new oil or something (also my coolant light was occasionally popping on telling me I was low-main reason I brought it in early). So they looked into it.
I'm told my DISA valve is worn and that it is a $215 part. I can't remember now if that was labor included. So i'm wondering if this is a part I could purchase and easily change out myself? I have an extended warranty with another company, but I was reading on it and if I'm interpreting correctly they won't replace any valves unless its cause a malfunction with the engine. I'm going to call and see what they say, but I'm looking for ideas on how to swing it so that they'll replace it.


On the plus side, got the car back all clean (was freaking dirty) and boy does she run now! I had noticed but could never put my finger on it to say something was wrong that she seemed slightly sluggish. Not any more, she has her "pep" back. Throttle response is a lot quicker/more refined now even without sport mode. Shifting seems more fluid as well. I'm really glad I noticed a significant difference after the inspection II was completed. Now I don't feel as cheated out of my money by the stealer.

Another interesting thing to note, apparently my windshield was replaced at one point but no one put in a new/old rain sensor. No wonder mine doesn't work! I'm going to call Carmax and see what they have to say, but i'm sure i'll be SOL due to the time being way way beyond 30 days.

 

[ElegantSpoon]

My 2.2 sounds like it's got a turbo. I thought it was just a bimmer thing?

 

[Aebous]

Well they do have a "ghost whistle" just not sure if this is it or not.





Oh, I forgot to ask, what's the average life of a DISA valve? Has it failed prematurely?
I hate when that happens.

 

[mystik]

sorry about the rain sensor issue! when i went to get my windshield replaced.... i had to hassle the guy every day asking if they put the sensors. i guess those people always forget those types of things. dumb..... you'd figure they'd get things done right the first time so as to avoid any issues later on in the road. whatever though*

 

[Thork]

I guess it's too long for me to say I'm updating. I didn't feel what I'm going to say deserved a new thread...
At any rate I'm bumping. My previous statement is still true and so begins my story.

I was creeping up on 3k left till Inspection II time and dreading every moment. The other day I decided to go get it done (i'm out of warrenty). I told the dealer feller about my ghost whistle and a suspected vacuum leak and also that the engine sounded rough like it needed new oil or something (also my coolant light was occasionally popping on telling me I was low-main reason I brought it in early). So they looked into it.
I'm told my DISA valve is worn and that it is a $215 part. I can't remember now if that was labor included. So i'm wondering if this is a part I could purchase and easily change out myself? I have an extended warranty with another company, but I was reading on it and if I'm interpreting correctly they won't replace any valves unless its cause a malfunction with the engine. I'm going to call and see what they say, but I'm looking for ideas on how to swing it so that they'll replace it.

Man, I'm glad that you finally found the cause of the whistling on your car. Good luck with the repair