Engine Whistle - Intake Boot

[simonlpearce]

Ok so the problem i had was that under load between 1.5k and 2k revs i got this really annoying whistling sound, which when i put on a new air intake got worse. So from this i figured that it must be something to do with the intake tubing, i also found a lot of help on *cough* another forum.

Basically over time the following parts perish due to excessive heat in the engine bay, the parts below are what you require to sort the problem out. This and a decent socket set, a hell of a lot of patience and a few hours to figure out just how to get the circlips undone (they put them in the most fiddly of places!)

03 - Rubber Boot 13541438761 = £14.05 + VAT (Stelership)

06 - Tube Elbow 13541438759 = £7.07 + VAT (Stealership)

Ok so first you need to remove either stock or aftermarket airfilter, this is very simple. All you have to do is remove the MAF from the filter housing then simply undo the two bolts holding the housing to the chassis.

Next you need to remove the MAF which again is held in place by circlips and the sensor which simply unclips. Further down you need to remove the Rubber Boot by undoing the circlips again and another sensor (not sure what it does) give it a good tug to get it out. The Rubber Boot connects to the tube elbow via a simple connecting ring this will also need to be removed simply by undoing the circlips.

To get to the circlips holding the Tube Elbow to the intake manifold you will also have to remove another part (not sure what it is) pictured below. Keep this somewhere clean and free of dust or contaminants as it looks like it is important.

As you will see just behind in the picture above the Tube Elbow is still attached, by removing the part pictured above it gives you a little more room to play with when trying to get at those last few circlips. This part simply has a sensor on top which just unclips, and two hex bolts securing it to the engine, remove and store safely.

NB - Be careful not to drop anything whilst doing this as its a PITA to get things out from in the splash tray!

Actually removing the Tube Elbow took me a good hour to figure out and a lot of cramp and contorsion. My arms and elbows bent in ways they never have before when trying to get at the last 2 circlips.

The next picture shows everything removed.

This picture will show you exactly what was causing the whistle on the intake, so well worth checking your intake boots even if you havent noticed this whistle. This is the part that will give you temporary tirrets and you will lose some skin from knuckles. It is possible to get to the last 2 circlips just be patient and try from lots of different approaches.

From here things are a little easier as you simply have to rebuild what you have just taken off, but make sure you locate the circlips so that it is easier next time you have to remove anthing, see pics. As you will see i have now located the screw heads so they face upwards. On removal they were all facing down so i could not see how to get at them and had to come from underneath.

And finally a picture of it all assembled, as you will find its a lot easier to put back together than it is to remove. Simply reattach the Tube Elbow to the manifold using 1 x large circlip and 1 x small circlip, insert the connecting ring to the Tube Elbow and secure with circlip, attach Rubber Boot to other side of connecting ring and secure with circlip and finally attach MAF to rubber boot and secure with curclip making sure to plug in MAF Sensor.

All that is left to do after this is reattach the important looking part including the sensor, reattach your MAF including sensor, reattach the other sensor that you had to give a good old tug to get out (dont know what it does) and finally reattach you aftermarket or stock air filter. All of which simply use circlips (yes im sick of writing the blooming word circlip)

I do have a full compliment of pictures if anyone needs them as i know this is a little vague for a DIY, its really common sense though you will see what i mean when you come to do it.

PM me if you have any questions or need a little advice with anything.

[MattBMW]

SI nice little write up m8 well done....do the parts have to be purchased from a stealer or can they be purchased form the likes of GSF or Euro carparts?

[simonlpearce]

SI nice little write up m8 well done....do the parts have to be purchased from a stealer or can they be purchased form the likes of GSF or Euro carparts?

I did go into GSF and gave them the part numbers from realoem and they didnt have anything, not sure about Euro Car Parts didnt try. Stealers seemed pretty reasonable plus i needed some fog light surrounds which they did for £3.52 each inc VAT so i was happy.

[Dicky]

Good write up mate, I will check mine at the weekend

Glad to hear you got the fog light surrounds

[simonlpearce]

Yeah they were much needed, just need to prep and paint them now, along with my rear diffuser - Oh and lets not forget calipers

[DaveDunlop]

nice one mate, good write up to match.

[simonlpearce]

I have just noticed that the item in the first picture look mahooosive, almost the size of the engine! Its really not that big, its about 6" long and 3" wide (ooohhhh suits you sir)

[amowolves]

Simon...ur getting quite good at this d.i.y write up malarky aint ya! good lad...keep em coming.

[simonlpearce]

Haha, well you see i get well fed up when looking for DIY's on the simpler things and not being able to find them so i want new people on here to not have this problem. I also thought it would be nice for them to not have to be referred to an alternative forum!

Will hopefully have DIY's for all fluid changes coming up over the next few weeks so watch this space

[Jay631]

Damn ggod write up man I am gonna check mine during the week.

Your lucky you didnt suck any Cr*p up through the holes into the engine... could have been bad!

[simonlpearce]

I dont think this effected pipe actually goes into the engine, im not 100% sure where it goes TBH. Either way the best thing is that i no longer have the annoying sound when pulling away.

One thing i forgot to mention was to make sure you are uber clean with everything in that area, as above you dont want any unpleasant nasties getting into your finely tuned engine!

[Jonny]

Si,

Brilliant write up mate, think i'm having the same problem so will check this out soon.

[simonlpearce]

Si,

Brilliant write up mate, think i'm having the same problem so will check this out soon.

PM me if you get stuck, its a fiddly job but can be done.

[Rob.S]

personally I'd want to use main dealer parts and not the half decent stuff the gsf and ecp fob you off with.

Dealers are that expensive and are usually really helpful

[duffman]

excellent write up simon!

well done

[Wayne'o]

done mine not too long ago ago the write up was really helpful

and the part was only £12.27 inc. VAT

bargain and makes a hell of a difference

Thanks Si

[stringy93]

Good write up Si, did mine today and it was abit of a pain. No skin left on my knuckles but the Tube elbow was split all over so needed doing.

Neway its cured the whistle and the car seems to drive better, result

The part numbers for a 323ci if anyone is interested are

13541705209 - Rubber Boot - £9.05 +vat

13541435627 - Tube Elbow - £7.57 +vat

[328i]

i think i have this problem. wht is the noise that u hear when you pul off.

[nps27]

i think i have this problem. wht is the noise that u hear when you pul off.

Hi, Just had my 330d remaped, a few months after i got this squealing noise or alike whisle noise when i accelerate, its getting worse, I just ready this post and will investigate next week when i have a day off. Hope it is just a broken induct

[simonlpearce]

The noise i like i high pitched whistle.

If either of you need any help let me know via pm.

[nps27]

went to take the engine bay top off today and just before we noticed the front air intake rubber lip (just above fan and front gril) was just showing a gap and the clips where almost off!, resecured the intake and relined all vac pipes and all great! no noise anymore! and engine seems smother. will take some pics tomorrow and show you.

UPDATED;

Spend a full day stripping down the air intake system (repaired front intake cover), vacuum system (new vacuum pipes), cleaned the manifold and all fittings, replaced small washer which had been crushed by last person that had the manifold off! So the manifold was not fully secure where the washer was crushed. Spent 2 hours cleaning the EGR valve as some sort of black snow drifts had occured within! Took some shifting with 2 cans of clutch and break cleaner and half can of WD40!

New airfilter and Everything clean and back together and checked, no bolts left over happy to say, after a coffee we took her out, it has made a big difference to how the car performs, runs and sounds. I dont get haf as much black stuff from the back when i put my foot down either.

Next job is a new throttle modual to fit, I not had full kickdown as stange 2 sensor has died for about a month now!

Also looking for a intercooler as people tell me that the one i have is too small for the remap! If anyone knows about which one is best for the 2003 330d m57 engine build please let me know

[ian330d]

Hi all, newbie here, I have a whistle on my 2001 330D at 40 & 75 (poss rev related), but the 330D engine/intake layout is v different, any ideas where to start guys?

Cheers

[simonlpearce]

Hello mate, sorry i cant be of much help on this one as i dont have a diesel but im sure if you trace the intake pipes back through the engine you should be able to find the culpret. Just mae sure you keep everything clean when doing this as the last thing you want is something getting stuck in your turbo!

[minty]

fixed this issue at the weekend, exactly the same problem with the perished part, I bought both pipes from the stealers though and renewed both while they were off the car... printed your write up out, helped along the way so thanks very much mate! Paid £25 all in from the stealers, took a couple of days to come in.

Everything was going smoothley until the last pipe coming off...

1st problem I had was that my hands are quite big and cant get into tight places (no jokes please - oo er!) - 2nd problem, the last 2 clips holding the pipe were facing away and down into the engine bay! my neighbour actually came out to make sure I was Ok as he could hear so much swearing and FFS's!!!!! I got so wound up after loads of failed ideas - I ended up taking a stanley knife to the culprit pipe and cut it right back to where they joined to the engine (sorry im not that techinical) and chopping away everything as much as I could - just so I could get my hand in and around to turn the screw nut with small spanner - slowly but surely I got it off, within 10 mins I had fitted everything new and old back to its rightful place! Easy.... wish the previous 2 hours had gone that smoothly! refitted the clips in postitions that make common sense and I can get to again if I need too.... zee germans obviously didnt think that bit through very well!

Anyway - rant over, problem fixed, very happy, cheers Simon

[Natedogg]

wondering about mine now - not so much of a whistle as a sort of low honk noise as i pull away - always thought it was the auto box but maybe i should check some pipes now on saturday and see whats whats under there.