DIY: Intake boot replacement. No more whistle while accelerating

i like this.

Originally Posted by jdny516

not sure if you said this, but when you put in the new boot, you have to make sure the "tab" slips in correctly. Hope that makes sense?

Great Write Up

i just popped it on so it was snug and wouldnt come off if i pulled it. it didnt matter where the tab was that is on the bottom of the boot if thats what you are talking about...


but this mod works, it got rid of an annoying whining sound when normally accelerating... but i still get a high pitched screech like a turbo that starts at 5500 rpm and gets louder the higher the RPM when im flooring it, people ask me if my car is turboed all the time lol, i just think its embarrassing . i have a vacuum leak somwhere else, i need to find out where it is, im thinking its the upper intake hose, the rubber is no longer that soft, its become dry and cracked so im thinking theres not a good enough seal behind the MAF.

Originally Posted by ///M=Power

i just popped it on so it was snug and wouldnt come off if i pulled it. it didnt matter where the tab was that is on the bottom of the boot if thats what you are talking about...


but this mod works, it got rid of an annoying whining sound when normally accelerating... but i still get a high pitched screech like a turbo that starts at 5500 rpm and gets louder the higher the RPM when im flooring it, people ask me if my car is turboed all the time lol, i just think its embarrassing . i have a vacuum leak somwhere else, i need to find out where it is, im thinking its the upper intake hose, the rubber is no longer that soft, its become dry and cracked so im thinking theres not a good enough seal behind the MAF.

may not be another leak, i heard something about that whistling noise coming from something that pulls to use more torque? I could be completely wrong on this.

Originally Posted by jdny516

may not be another leak, i heard something about that whistling noise coming from something that pulls to use more torque? I could be completely wrong on this.

never heard of anything like that...

Everyone thinks Ive got a turbo so idk...It annoys me though lol. I can take a video and show you. It just bothers me how I can't find the source

but the new intake boot made my car run much smoother no more rough idle.

I did notice on the stock airbox there is a spring loaded valve kind of thing, it's a 2 inch wide circle of plastic with a spring behind it, and you can push it into the airbox, is this for when you don't have enough airflow?

just wondering is this the same whistling noise you had? http://forum.e46fanatics.com/showthread.php?t=766313.. Thanks

Originally Posted by Dgwapito

just wondering is this the same whistling noise you had? http://forum.e46fanatics.com/showthread.php?t=766313.. Thanks

im pretty sure that noise is not from the intake boot. That sounds horrible! Maybe something in your belts/pulleys? Definitely have that checked out. Hope everything works out

Great pictures!

Having one of these made it super easy........



Also, to get to the hard to reach areas I used..

i changed the intake boot on my car too, but it is still the same think. it still has a whistle. anybody find a fix for this?

I'd add one step...when the throttle body is exposed put an absorbant wrag below it, reach in and open the butterfly valve and spray a bunch of Deep Creep inside.

I cut a whole in my air box a while ago and I cant remember if the whistle started after that or later on but it defiantly whistles now, more often at lower rpm's like when starting from a stopped position. is the whistle a leak or is it from the whole in my air box?

Great write up!! Imma do this next after dropping my oil pan and radiator replaced three weeks ago this should be a piece of cake!

Great post...thanks! Unforfunately, I was unable to get that smaller intake tube off the engine!! I worked like a dog just getting to that small clamp...got it loose...but the damn thing would not budge!! I did get to inspect it and lucky for me it seemed intact so I put everything back together and had a cold beer to ease my bruised ego. Great price for the intake tube from the good guys at Bavauto.com...$15.
Still getting a sometimes very loud whistle decelerating to a stop. Sounds a bit like a "cartoon bomb" dropping...anyone have any ideas? I have a 323i sedan with a 5spd.

nice writeup! Quick question though, on Tischer's site it's lists this part number for a 330. Is it the same for a 325?

any tips to loose the hard to reach clamp?

Thanks for the great DIY. I just did it after work and completed a test drive to see if it solved my SES light. All is well again. I did however run into a problem I haven't seen yet on any DIYs. My upper intake boot has one plug on top (as noted in the DIY), but on that one plug, it splits into two parts. One is the thicker hose, one is a short thinner hose that connects to some sort of steel tube that goes under the engine.

The smaller one disintegrated when I touched it and I have no idea what it goes to. It did not affect the idle or performance during the test drive but I want to get a short piece of tubing to reconnect the hose. Any ideas what it might be used for? Makes me nervous.

See pics attached

I am getting L&R bank lean codes causing my CEL to stay on. Seems as though many of you suggest this boot replacement could fix the problem. I am reading the MAF could also be bad which I have located in other threads. My question for this thread is this: Once the boot is replaced is there a sequence that must be done to reset the CES or will it shut off automatically once the issue is fixed? Or will i just have to have someone reset the computer?

i just finished putting my 2001 330 ci back together , it was pretty straightfoward job witht the DIY info on here . i did have a particularly hard time with the screws on the clamp but now theyare turnrd properly and easy to reach for next time . I repalcedboth bootsand cleaned my throttle body and the iac that the small boot attatches to. My car was pulling 13 codes mostly lean bank and misfire codes ,i cleared the codes and so far no reapearence yet. the small hard plastic tube that attatches to the piece on top of the front intake tube broke on mine too ,not sure what this does but i plugged it with a small screw and so far no notice in performance or new codes

Originally Posted by tfoxsf

Thanks for the great DIY. I just did it after work and completed a test drive to see if it solved my SES light. All is well again. I did however run into a problem I haven't seen yet on any DIYs. My upper intake boot has one plug on top (as noted in the DIY), but on that one plug, it splits into two parts. One is the thicker hose, one is a short thinner hose that connects to some sort of steel tube that goes under the engine.

The smaller one disintegrated when I touched it and I have no idea what it goes to. It did not affect the idle or performance during the test drive but I want to get a short piece of tubing to reconnect the hose. Any ideas what it might be used for? Makes me nervous.

See pics attached

Update: I ordered a coil of flexible vacuum hose from PelicanParts.com and cut a 4 inch section off. I then connected it to the bottom of the 'F' connector and then to the metal tube that is next to it (the tube then goes under the engine). Problem solved.

checked out this DIY halfway through the job, while I was trying to get the bottom hose clamp off. Removing that black heat shield made the install go smooth. Rather than fight with the top smaller hose I just loosened the clamp until it slid all the way back and put a small slice in it with a razor blade. The part it connects to seemed to delicate to pull on.