[DaveH28]

This may or not be an issue, it's done this since I got it, I have been waiting till over 1200 miles to give it some.

Basically when I accelerate...there seems to be a tapping on top of the exhaust note, in sync with engine revs. Like a rattle..sounds to be coming from engine rather than exhaust.

If this is correct and I'm too used to diesels then ok...but do any other fellow 40i drivers hear this. Very hard to describe.

[stefan4]

I hear a slight tapping noise, particularly at low revs when hard on the throttle. I've put it down to the chain and VANOS system being at the back of the engine.

[SpaceHorsey]

I have a 40i and I know the sound you mean.

It's the injectors. Modem injectors sound like old engines when they got old and "tapetty"

So now when you buy a brand new car it already sounds old. Best just to do the exhaust valve mod and floor it everywhere you go with the windows down.

[snipnoob86]

sounds more like the lifters to me, perfectly normal

[DaveH28]

Cheers guys, sounds like it's normal then..

I remember something similar on my old corsa Sri....long time ago that was like an electrical crackle..

There is nothing wrong with the way it goes, so after having a quite progressive drive tonight I wanted to ask the question.

The sheer acceleration when going from 30ish is just ridiculous...surprises me every time.

[Daftasabrush]

If you take the engine cover off and give it a brief blip, you'll hear just how loud the injectors can be, it makes it sound like a diesel!

[Proftinkerpot]

Better buying a diesel and then at least you know what the rattles are 😆

[ak335dxdrive]

wowsers.
and i was thinking sod it with the consumption just go and get a 340i.
but i think i ll stay where i am.

[Daftasabrush]

Originally Posted by ak335dxdrive

wowsers.
and i was thinking sod it with the consumption just go and get a 340i.
but i think i ll stay where i am.

Because the injectors are noisy? Fairy nuff...

[HiBee]

TBH not heard anything unfamilier. Normally music is on as the start button is pressed.
Will pay more attention since it's been noted.

[ak335dxdrive]

Originally Posted by Daftasabrush

Because the injectors are noisy? Fairy nuff...

Easy tiger. I was just kidding. No need to take offense.

[KS_340i]

Not heard anything on mine...

[HighlandPete]

Originally Posted by Daftasabrush

If you take the engine cover off and give it a brief blip, you'll hear just how loud the injectors can be, it makes it sound like a diesel!

For those familiar with both engines, are the injectors in the B58 engine typically making more noise than the N55?

[KM79]

Yes the new B58 engine has noticeably more injector noise than the n55.Completely different injection setup than its predecessor,runs at tighter tolerances etc.First thing I noticed the first time I started up a 340i.

[ewanmac]

Unfortunate consequence of direct injection. If you listen to a pre direct injection I6 to a modern one they do sound much quieter.

I remember the first time I heard my old 335i I thought it was almost diesel like at tick over.

[Rich9600]

Originally Posted by Proftinkerpot

Better buying a diesel and then at least you know what the rattles are 😆

I had a 2h test drive in a 40i... Coming from a 30d with the half decent HK sound system and loving music...

The radio did not get turned on once during the 2h and the Windows went down often.

No unpleasant noises in that car... And driving through villages of two rows of mining terraces was great.

[BnB]

I found the 340i quite diesel-ish at low speeds on my test drive. A bit clattery, lots of torque. Then I wrung it's neck, forgot all about mpg and had a blast. Order was placed a day or so later..

[DaveH28]

I wasn't really talking about a diesel clatter sound. It's more on the acceleration it is a tapping sound...I'm sure it's just the injectors

[elstoof]

The N20 in my 125i makes a lot of tappety noises at idle, a bit less once warmed up but still very much there. The 340i test drive was silent in comparison to that, just had that I6 sound filling my ears.

[stefan4]

Originally Posted by elstoof

The N20 in my 125i makes a lot of tappety noises at idle, a bit less once warmed up but still very much there. The 340i test drive was silent in comparison to that, just had that I6 sound filling my ears.

Yes, I noticed the same coming from my n20 320i

[RobUK]

Originally Posted by BnB

I found the 340i quite diesel-ish at low speeds on my test drive. A bit clattery, lots of torque. Then I wrung it's neck, forgot all about mpg and had a blast. Order was placed a day or so later..

That's interesting, I'm finding the engine very refined almost too quiet at low speeds, although even at slow speeds if you pop it in Sport and lift off you can hear it softly burbling to itself. Under more enthusiastic conditions, I'm not getting any diesely clattering - maybe it's a feature they added to the later builds

[BnB]

Originally Posted by RobUK

That's interesting, I'm finding the engine very refined almost too quiet at low speeds, although even at slow speeds if you pop it in Sport and lift off you can hear it softly burbling to itself. Under more enthusiastic conditions, I'm not getting any diesely clattering - maybe it's a feature they added to the later builds

Yes it was rather quiet below 4k (revs not mph) on my test drive. Lovely sound when revved properly, not diesely then. Much nicer than the M3/4 noise as well.

Still waiting for mine to be built as Individual options hold back the order.