BMW E92 330i N53 warm engine whine

[Herby303]

Cheers Soup/Mike

Sounds like the hard bit is done then, cool.

Didn't realise it had small screws on the side, nice one. Was thinking maybe a jubilee clip, but no need then.

Thanks again for all the posts here, may have saved me and a few others £££

I'll post results when I get it

[Herby303]

Update

Finally got the membrane and cap.

They couldn't send it straight to me as Russia cant deliver to the UK at the moment, but they kindly sent it to a friend in another country who sent it to me, got it on Saturday.

Fitted it yesterday, seems to fit really nice, and as you say, Mike, the screws on the outside help. Did 50 miles today with no codes at all, and no rough idle at any point, great!

If this has fixed the problem which BMW quoted me £2100 to fix (full injector replacement) I'll be buzzing with that

I'll give it a good run this week and see how it goes.

Thanks again all, particularly Soup/Mike, been chasing these codes for months

[Herby303]

Final Update

Almost a month of driving, no issues at all. Completely fixed

Cheers

[bmwmike]

Well done!! Nice to hear.

[SoupAnxiety]

Great news, well done for sorting!

[Masonfantana]

Hi all,

Very very long time lurker.
Just signing in to say a big thanks to Soup, I replaced the membrane and installed the metal cap a few weeks back. My membrane was in awful shape!

With Soups info i managed to source the problem with my rough idle and general rough running, it got to the point where my car was stalling and had become quite a handful to drive

Also had a NOXEM fitted before that too

Car is now running great and has never felt better!

Thanks man

Edited by Masonfantana on Monday 12th April 18:19

[grejsi]

So I've made an account just to ask this.

From reading the thread I am now 99% this is my issue, I have pretty much all but the most severe symptoms.

I've ordered the membrane + cap from Vanos BMW now, god knows when it'll arrive but that's a separate issue...

What I still don't understand is the membrane gluing, should it be glued to the inside of the aluminum cap? If so, what's the point of a ventilation hole in the aluminum cap then?

Or should it be glued to the valve cover itself? If so, what's the point of the membrane if it's glued in place? I though the whole idea was that the spring regulates the position of the membrane.

The cap has tiny screws in it to secure it to the valve cover, so I'm sure some Loctite sealant I still have from diff replacement and the screws is more than enough to secure the aluminum cap to the valve cover.

Maybe I'm being stupid but some picture of where/how the membrane should be glued (or should it not be glued at all and just sit on top of the spring?) would be immensely helpful.

N53B30 in an E91, 100k miles on the dot.

[SoupAnxiety]

grejsi said:

So I've made an account just to ask this.

From reading the thread I am now 99% this is my issue, I have pretty much all but the most severe symptoms.

I've ordered the membrane + cap from Vanos BMW now, god knows when it'll arrive but that's a separate issue...

What I still don't understand is the membrane gluing, should it be glued to the inside of the aluminum cap? If so, what's the point of a ventilation hole in the aluminum cap then?

Or should it be glued to the valve cover itself? If so, what's the point of the membrane if it's glued in place? I though the whole idea was that the spring regulates the position of the membrane.

The cap has tiny screws in it to secure it to the valve cover, so I'm sure some Loctite sealant I still have from diff replacement and the screws is more than enough to secure the aluminum cap to the valve cover.

Maybe I'm being stupid but some picture of where/how the membrane should be glued (or should it not be glued at all and just sit on top of the spring?) would be immensely helpful.

N53B30 in an E91, 100k miles on the dot.

No need to glue - I used liquid gasket around the edge of the cap to improve the seal.

My N53B30 is on 200k now and all is well.

[bmwmike]

grejsi said:

So I've made an account just to ask this.

From reading the thread I am now 99% this is my issue, I have pretty much all but the most severe symptoms.

I've ordered the membrane + cap from Vanos BMW now, god knows when it'll arrive but that's a separate issue...

What I still don't understand is the membrane gluing, should it be glued to the inside of the aluminum cap? If so, what's the point of a ventilation hole in the aluminum cap then?

Or should it be glued to the valve cover itself? If so, what's the point of the membrane if it's glued in place? I though the whole idea was that the spring regulates the position of the membrane.

The cap has tiny screws in it to secure it to the valve cover, so I'm sure some Loctite sealant I still have from diff replacement and the screws is more than enough to secure the aluminum cap to the valve cover.

Maybe I'm being stupid but some picture of where/how the membrane should be glued (or should it not be glued at all and just sit on top of the spring?) would be immensely helpful.

N53B30 in an E91, 100k miles on the dot.

As Soup says dont use glue. I used RTV.

First things first, use a light bead to seal the diaphragm to the cap. Let it set. Then, you should be able to pull on the diaphragm whilst holding the cap, and it'll breathe through the little hole. If you block the hole, you wont (shouldnt) be able to expand the diaphragm. So yes the diaphragm must be sealed to the cap and airtight, otherwise when you install the cap (with diaphragm inside it) the engine may breathe through the little hole.

Hope that helps explain what the hole does if not let me know.

Link helps too https://bimmerprofs.com/crankcase-ventilation-part...

Go easy on the RTV sealant to cap, it needs to move freely.

Second, RTV the cap to the cam cover. Make sure its all spotless and let it set. Job jobbed!

[grejsi]

bmwmike said:

As Soup says dont use glue. I used RTV.

First things first, use a light bead to seal the diaphragm to the cap. Let it set. Then, you should be able to pull on the diaphragm whilst holding the cap, and it'll breathe through the little hole. If you block the hole, you wont (shouldnt) be able to expand the diaphragm. So yes the diaphragm must be sealed to the cap and airtight, otherwise when you install the cap (with diaphragm inside it) the engine may breathe through the little hole.

Hope that helps explain what the hole does if not let me know.

Link helps too https://bimmerprofs.com/crankcase-ventilation-part...

Go easy on the RTV sealant to cap, it needs to move freely.

Second, RTV the cap to the cam cover. Make sure its all spotless and let it set. Job jobbed!

Thank you for the link, where would the membrane be glued to the cap ideally? in the middle above the spring?

Also I'm not sure I follow how "seal the diaphragm to the cap" and "it needs to move freely" go together, Isn't this contradicting information?

Gosh this makes me feel like an idiot, using the image on the bimmerprofs website, could someone please make some sort of visual representation of the gluing/sealant locations?

Or is the spring attached to the membrane, which is then attached to the top of the inside of the cap? And the membrane doesn't actually move at all (which is what I've assumed all along)? If so, what's the spring for?

Or maybe my ESL is failing me, is membrane/diaphragm the same thing, or is one of them a specific part of the other?

[bmwmike]

If you place the diaphragm into the cap, you will see that it slots into the perimeter/edge. Its there that you need to run a thin bead of sealant. The inner parts of the diaphragm must move freely.

The diaphragm is basically a plunger/valve that when vacuum is applied beneath the spring it sucks the diaphragm down and blocks off the vacuum.

[grejsi]

bmwmike said:

If you place the diaphragm into the cap, you will see that it slots into the perimeter/edge. Its there that you need to run a thin bead of sealant. The inner parts of the diaphragm must move freely.

The diaphragm is basically a plunger/valve that when vacuum is applied beneath the spring it sucks the diaphragm down and blocks off the vacuum.

Thank you! That clears it up for me, no one clarified that you were only supposed to seal the outer edge...

[grejsi]

Just got an email from vanos-bmw clarifying that they can't send it to me (for obvious reasons), my only options are either to have it sent to a friend in a country that can receive it or receive a refund (but then I still need to actually solve the whistlng membrane that keeps getting worse)

If anyone knows of a way to circumvent this (are there other vendors outside of RU?) or know they can receive it to then send it to Sweden please let me know

[bmwmike]

grejsi said:

Just got an email from vanos-bmw clarifying that they can't send it to me (for obvious reasons), my only options are either to have it sent to a friend in a country that can receive it or receive a refund (but then I still need to actually solve the whistlng membrane that keeps getting worse)

If anyone knows of a way to circumvent this (are there other vendors outside of RU?) or know they can receive it to then send it to Sweden please let me know

I bought a chinese one, black plastic off ebay and it came with diaphragm, spring and cap and it works great, looks original

[grejsi]

bmwmike said:

I bought a chinese one, black plastic off ebay and it came with diaphragm, spring and cap and it works great, looks original

Gotcha, I found a UK seller selling cap + membrane + spring, shame since I wanted the aluminum one and I could only find plastic ones elsewhere but what can you do :/

Is there anything I should keep in mind when removing the old cap?

[bmwmike]

grejsi said:

bmwmike said:

I bought a chinese one, black plastic off ebay and it came with diaphragm, spring and cap and it works great, looks original

Gotcha, I found a UK seller selling cap + membrane + spring, shame since I wanted the aluminum one and I could only find plastic ones elsewhere but what can you do :/

Is there anything I should keep in mind when removing the old cap?

Take care not to damage the valve cover itself. I went in through the centre of the cap and worked outwards, it peels off pretty easily. Send us a pic of how bad your diaphragm is. Its a crappy (but common) design.

[grejsi]

Finally got it done, I decided to take some pictures and elaborate on the parts that I struggled with myself.

Imgur album: https://imgur.com/a/7CjuGec

My symptoms were: Whining/vacuum sound on idle, obvious whining when accelerating moderately "supercharger-esque".
Would sometimes hesitate very slightly on cold start, but never any persistent running issues. With headphones on you'd never know there was an issue, if that makes sense.

The hardest part for me was removing the cap, it isn't difficult but rather annoying and time consuming. If you have a chance to do this with the valve cover off, then DO IT! The location makes it a pain work on, stretching over the engine bay for long periods isn't nice on the back and calves.

Pro tip: use lots of heat, it makes it waaaaaay easier to get the cover loose in one place. And once the seal is starting to go you can simply use a heat gun and slowly go around with a knife/flathead to loosen it bit by bit..

Don't be fooled though, the job is simple. If I did it again it would be a 10-minute job, except the RTV curing of course.

[bmwmike]

Nice work getting the cap off in one piece. I was fishing bits of plastic out of nooks and crannies. Yours looked in good nick relatively speaking. Mine was toast at only 60k miles.

Not a bad job though and worth a try rather than 400 smackers for a new cam cover

[grejsi]

UPDATE:

After about 2 weeks of the new membrane and cap the car has developed the same faint whining on idle and does "wooshing" noises at very light load. It will also hesitate very slightly on idle after a cold start, sometimes you can only see the needle dip for a second and other times you'll feel it in the car. Definitely not a big issue but definitely not 100% either.

Scenario: Cruising at a steady 50km/h I'll lightly apply throttle to maintain speed (as in not accelerating) there's a clear air-sucking/wooshing noise coming from the engine.

I'll probably bite the bullet and re-do the job with more sealant and letting it cure for longer, if we stop having non-stop rain that is...

[SoupAnxiety]

grejsi said:

UPDATE:

After about 2 weeks of the new membrane and cap the car has developed the same faint whining on idle and does "wooshing" noises at very light load. It will also hesitate very slightly on idle after a cold start, sometimes you can only see the needle dip for a second and other times you'll feel it in the car. Definitely not a big issue but definitely not 100% either.

Scenario: Cruising at a steady 50km/h I'll lightly apply throttle to maintain speed (as in not accelerating) there's a clear air-sucking/wooshing noise coming from the engine.

I'll probably bite the bullet and re-do the job with more sealant and letting it cure for longer, if we stop having non-stop rain that is...

That does sound like the seal isn't 100%. I installed my cap in February 2017 and it's been fine in the years and many, many miles since. I used liquid gasket. At the risk of immediate borkage after writing this, my N53 is nearly on 200k.