DIY: Intake boot replacement. No more whistle while accelerating

Great DIY! I'm very thankful for this site and all the info.

Yes it was a PITA. My clamps were all in difficult positions. I had the infamous whistling sound and when I got in there i found this was why:


I put in the upper and lower boots and the next morning my SES light went away and I was very satisfied. Even had more low end power.

But the next day, the SES light came back on. Looks like the positioning is off and the upper tube is bent a little. Hmm. Hope some repositioning will fix it.

For those that remove the DISA valve to access the lower boot, be aware that, with a few miles on the car, the old seal might leak and cause issues (running rough, setting codes, etc.) when its reinstalled. Just inspect for vacuum leaks at the interface of the DISA to the intake runner manifold. Mine had a vacuum leak and I had to take it back out to seal it with some RTV. Just FYI...

I have the whistling under acceleration above around 2600 RPM, but no CEL or SES. Do you guys think the intake boot is still to blame?

Originally Posted by Tate325xi

I have the whistling under acceleration above around 2600 RPM, but no CEL or SES. Do you guys think the intake boot is still to blame?

Have it too after intake boot replacement which I found out afterwards was almost new
Seems worse in heat

can anyone tell me where i can get replacement fixings for the black wall near the brake booster? lost mine!!

Well i was getting codes bank 1 and 2 to lean. replaced the air flow sensor and reset the light. code came back a week later. i did a smoke test and found all the vents pipes under the intake leaking. followed this DIY yesterday and what a PITA!!! did replace all the pipes and the oil separator. replaced the intake manifold gaskets, cleaned the injectors. turn the car back on and it idles very rough. haven't driven the car yet but going to work today so lets see. the light is still on but i will reset it today and see what happens. hope this was the problem.

JC86 the little tabs you are looking for are cheap from BMW. you can get it from them dirt cheap.

do you guys know if the SES light needs to be reset after this or should it turn off my its self?

I just did this today and it wasn't nearly as difficult as I thought it would be. Although I had a hole in the smaller tube, I didn't have a noticeable whistle, but I did have the SES light that would not go away.

I didn't remove the cabin filter stuff or the small kick panel thing as it was only a little obstructive. Also, since the smaller tube was already split, I cut it through so I could pull the lower boot off first, then I could work on the smaller piece. It was a gamble to cut it because I had to have the car back together by a certain time for my wife to go out of town. Luckily, I was able to get to it and remove it easily.

I also cleaned the throttle body and the IAC module while I was in there. I cleared the SES light and took it for a drive.

Thanks for the write up!

I have a whistle at the beginning of acceleration but it disappears when you give it more gas. Lower boot is new and no codes. Any ideas?

Had the whistle for a few months and figured it was in the intake somewhere. The SES light finally came on and I was forced to figure it out. Took a peek in and confirmed the boot is cracked. Ordering a new one today! Thanks

Originally Posted by Vault

Had the whistle for a few months and figured it was in the intake somewhere. The SES light finally came on and I was forced to figure it out. Took a peek in and confirmed the boot is cracked. Ordering a new one today! Thanks

New boot is installed and the SES light turned off the following day. A very satisfying repair. Thanks for the walkthrough!

Thank you for this diy!

Sent from my SCH-I500 using Bimmer App

Glad I could help I need to make more DIY's

Do you think this is the cause of my whistling at lower rpms 2000-2300?

Sent from my SCH-I500 using Bimmer App

Completed lower and upper boot plus DISA Gasket yesterday. I made it about about a four hour job. I was in no hurry. I did take the airbox out and went the DISA route. Left MAF in since I cleaned it several months ago. I have 59,000 miles on our 330CIC and I wanted to check Coolent & power steering tanks, hoses and belts and anything else I see. I took DISA out for several reasons. One to check gasket and it was shot. (lower than the ridge of the DISA grove...doing absolutely nothing, except leaking) The other to check for rattle and perform vacuum test and pin status. Replaced gasket with Ebay's best ($12.95) no gas or vehicle wear looking for a gasket.

I knew a had a rip in ICV hose on lower boot as I had sealed it months aqo with weather seal to get all the parts I needed to repair lower boot. My upper boot looked new so I didn't order that when I ordered lower boot. (Mistake) When I removed upper with a tug tug type pull and looked at the bottom it too looked good but when I spread out flex part, it was ripped in four places. Trip to BMW $47.10 later I was set. $29.95 German auto parts + shipping but I couldn't wait

As for the lower boot removal, I didn't mess around. Sock into trottle body I cut the boot off right at the trottle body. All of the problem clamps now fully exposed. I did use the suggestion/hint of a make shift tool in this tread to help you, was the allen wrench and 6 mm. Used this and few other tools. Once boot was out took pictures all over for the record and to see how things looked. On the lower boot I think it is better to hook up larger hole to get flange to match then the small hose . small hose clamp screw straight up so you can tighted from above Big clamp I went toward Disa hole, again for screwdriver. Putting in boot coupler and first band screw pointed toward fender. Used stubby screwdriver. Reinstalled DISA taped screws with 30 mm torx taped to my socket with masking tape. Boot covered with sock. I have a suspension support bar but that didn't get in my way. Almost There. Sock out. Installed upper boot. Don't fully tighten bracket. You need to leave loose so when you put airbox back in you can move to match the airbox. Plug back in Disa wiring ( disconnect is on engine side of plug) and MAF after installing airbox. go back tighten rear upper boot clamp. Install front air intake with three pins. Go treat your sore back and watch TV. Thanks to all for DIY to give me the nerve to do this. Went smooth.

Anybody have any idea what the PN is, or what system its attached to? I may need to replace the little plastic piece that both hoses plug into. It's extremely brittle and i don't want it sucking something into another part of the car.

EDIT: found it for anybody that is looking: 13327503677

Such a pain in the ass. FYI, the part numbers for 325i and 330i are different. the one for mine is 13541435627
I put the one listed by the OP into the car and came up short for fitting it onto the intake box. I got it on there, but as long as there aren't any leaks, and i'm able to fit it on the MAF, should i have any problems? I do NOT want to get in there again haha

Originally Posted by chris98891

Anybody have any idea what the PN is, or what system its attached to? I may need to replace the little plastic piece that both hoses plug into. It's extremely brittle and i don't want it sucking something into another part of the car.

EDIT: found it for anybody that is looking: 13327503677

Such a pain in the ass. FYI, the part numbers for 325i and 330i are different. the one for mine is 13541435627
I put the one listed by the OP into the car and came up short for fitting it onto the intake box. I got it on there, but as long as there aren't any leaks, and i'm able to fit it on the MAF, should i have any problems? I do NOT want to get in there again haha

That broken small hose leads to the fuel filter under the driver side of the car. Had the exact same problem. Was getting the P0102 code. So far changed the MAF, intake boots, F connector and the two hoses and checked the connectors for any crimps. Still throwing the same P0102 code. Anyone figure this out?

I just finished this and it took me about an hour and a half. Was kind of easy once I figured out angles for getting at those hose clamps. Unfortunately, the boot I replaced did not have a hole in it, but the one between it and the air box does. Hooray. When I got to the lower intake boot, I ended up removing that wall thing, and on installing the upper boot, I ended up removing the air box. Work smarter, not harder (as my former boss at wal-mart used to say constantly).

Originally Posted by SchatzieII

Completed lower and upper boot plus DISA Gasket yesterday. I made it about about a four hour job. I was in no hurry. I did take the airbox out and went the DISA route. Left MAF in since I cleaned it several months ago. I have 59,000 miles on our 330CIC and I wanted to check Coolent & power steering tanks, hoses and belts and anything else I see. I took DISA out for several reasons. One to check gasket and it was shot. (lower than the ridge of the DISA grove...doing absolutely nothing, except leaking) The other to check for rattle and perform vacuum test and pin status. Replaced gasket with Ebay's best ($12.95) no gas or vehicle wear looking for a gasket.

I knew a had a rip in ICV hose on lower boot as I had sealed it months aqo with weather seal to get all the parts I needed to repair lower boot. My upper boot looked new so I didn't order that when I ordered lower boot. (Mistake) When I removed upper with a tug tug type pull and looked at the bottom it too looked good but when I spread out flex part, it was ripped in four places. Trip to BMW $47.10 later I was set. $29.95 German auto parts + shipping but I couldn't wait

As for the lower boot removal, I didn't mess around. Sock into trottle body I cut the boot off right at the trottle body. All of the problem clamps now fully exposed. I did use the suggestion/hint of a make shift tool in this tread to help you, was the allen wrench and 6 mm. Used this and few other tools. Once boot was out took pictures all over for the record and to see how things looked. On the lower boot I think it is better to hook up larger hole to get flange to match then the small hose . small hose clamp screw straight up so you can tighted from above Big clamp I went toward Disa hole, again for screwdriver. Putting in boot coupler and first band screw pointed toward fender. Used stubby screwdriver. Reinstalled DISA taped screws with 30 mm torx taped to my socket with masking tape. Boot covered with sock. I have a suspension support bar but that didn't get in my way. Almost There. Sock out. Installed upper boot. Don't fully tighten bracket. You need to leave loose so when you put airbox back in you can move to match the airbox. Plug back in Disa wiring ( disconnect is on engine side of plug) and MAF after installing airbox. go back tighten rear upper boot clamp. Install front air intake with three pins. Go treat your sore back and watch TV. Thanks to all for DIY to give me the nerve to do this. Went smooth.

UpDate: A lot of post just drop off and you never really know what fixed their problem. All of the parts above, I stated were bad. Boots & Disa Gasket. I still had that nasty smell occassionally. It turned out to be the leaky windshield washer pump's little hole at base causing water to splash on fender and to exhaust manifold and I think also maybe getting into Oxygen sensor. Read that on another post to check. My Vacuum leak was a part little mentioned but was a culprit for me. The Oil filler intake neck cap gasket on top of the engine was smashed so thin it really didn't function. Siliconed/new gasket Smell #2 and vacuum leak found. Codes PO 171 PO 174 self cleared and I immediately knew I was on to something as idle picked up 100 RPM's and the Bimmer feels great.

Im having a really hard time getting the lower intake boot back on, more so then getting it off, any advice?