[normelton]

Hi,

I love the way the M40i drives. Plenty of pep, sounds great, accelerates smoothly. Fantastic vehicle.

When I fire it up, the engine roars to life for about 10-15 seconds, then calms down. It's like the exhaust is tuned for a sports-mode "roar" before settling down to a comfort-mode "whir".

Any idea why that's the case? Is it just to make the driver feel better? That's cool and all, but I don't need my car growling at the neighbors every time I go to work.

Norman

p.s. yes I know that's a heretical question

[kscarrol]

New to the M40i but I suspect it’s similar to the cold start on my E90 M3 where higher rpms at start are to help warm up the catalytic converters.

[freshxdough]

It's normal. For heating the cats. The exhaust alone at cold start though can be a bit loud for a quiet neighborhood. If you throw it into drive or reverse just after starting it will lower the rpm just a little and get rid of a lot of the loudness

[JSY]

Originally Posted by normelton

Hi,

I love the way the M40i drives. Plenty of pep, sounds great, accelerates smoothly. Fantastic vehicle.

When I fire it up, the engine roars to life for about 10-15 seconds, then calms down. It's like the exhaust is tuned for a sports-mode "roar" before settling down to a comfort-mode "whir".

Any idea why that's the case? Is it just to make the driver feel better? That's cool and all, but I don't need my car growling at the neighbors every time I go to work.

Norman

p.s. yes I know that's a heretical question

I really love the startup rumble of the 2018... The 2021 is so.... subdued. But I hear you, though - there's no way to start the car without everyone knowing.

[Skotcoop]

I've noticed mine idles at high RPM's after starting even after the engine is hot. Not as long as when its cold but maybe its taking into account outside air temps? Which have been in the 40s lately.

[Douggie]

Originally Posted by normelton

Hi,

I love the way the M40i drives. Plenty of pep, sounds great, accelerates smoothly. Fantastic vehicle.

When I fire it up, the engine roars to life for about 10-15 seconds, then calms down. It's like the exhaust is tuned for a sports-mode "roar" before settling down to a comfort-mode "whir".

Any idea why that's the case? Is it just to make the driver feel better? That's cool and all, but I don't need my car growling at the neighbors every time I go to work.

Norman

p.s. yes I know that's a heretical question

I wish there was a neighbour friendly "stealth mode" option when starting

[sbt007]

Originally Posted by JSY

I really love the startup rumble of the 2018... The 2021 is so.... subdued. But I hear you, though - there's no way to start the car without everyone knowing.

Really. My 2021 also a fairly loud cold start (similar to what the OP describes). It does not have the pop and bangs any more but I have no clue if the cold start is louder in 2018/2019s.

[Alias1431]

Other manufacturers have an ability to automatically disable the loud cold-start if within a certain time that you set. That would be perfect. Shut it the hell up at night. Don't know why BMW didn't have the foresight to include something like that.

[Douggie]

Originally Posted by Alias1431

Other manufacturers have an ability to automatically disable the loud cold-start if within a certain time that you set. That would be perfect. Shut it the hell up at night. Don't know why BMW didn't have the foresight to include something like that.

Inconsiderate @sshole designers? Lol.

[pritchd]

Check out the Bimmercode thread - I'm pretty sure it can be coded to be less loud - at least this was the case on my 2019.

[Joker Eh]

I love the cold start sound. I do find the start louder when it has been warmed up though.

[BimmerTom94]

Here is a YT video of the X3 m40i starting up (might be useful to compare?)

[AstroDude11]

Is it a used car? In that case, the previous owner could have included the "startup roar" exhaust option in a flash tune. Likewise, there is a "cold start noise reduction" option too. I know this is true with MHD tunes.

[JSY]

Originally Posted by sbt007

Really. My 2021 also a fairly loud cold start (similar to what the OP describes). It does not have the pop and bangs any more but I have no clue if the cold start is louder in 2018/2019s.

It was the first thing I noticed - the 2021 is surely loud, but the 2018 I felt had a louder rumble and seemed to rev down a little later. The 2018 felt more "earth-shattering" when cold started to me.

[freshxdough]

Originally Posted by Alias1431

Other manufacturers have an ability to automatically disable the loud cold-start if within a certain time that you set. That would be perfect. Shut it the hell up at night. Don't know why BMW didn't have the foresight to include something like that.

It's all about emissions. Most all exhaust emissions are at cold start when the cats aren't warmed up yet.

[Alias1431]

Originally Posted by pritchd

Check out the Bimmercode thread - I'm pretty sure it can be coded to be less loud - at least this was the case on my 2019.

I know you can code it off, but I really like the sound and want to keep it for most of my driving. I just wish I could disable it at night. I feel like an asshole when I need to go somewhere after 9pm. I don't want to piss off my neighbors by waking up their kids, etc.

[XxDanoxX]

I am really struggling to get behind someone complaining about the sound an X3 M40i makes, when most people buy M Cars for the performance and with it .....That sound it makes.

Why didn't you buy a 30d?

[Blacktemplar]

This is my 2020 model M40i on a cold startup with fuse 203 pulled. The primary flow initially comes through the RH exhaust branch but there is noise from the LH. A little noisier than with 203 in place, but not too antisocial.....

[TX3M]

Originally Posted by XxDanoxX

I am really struggling to get behind someone complaining about the sound an X3 M40i makes, when most people buy M Cars for the performance and with it .....That sound it makes.

Why didn't you buy a 30d?

What's not to understand? Some of us want the features and performance of the M40i but don't like the loud, obnoxious startup noise from the exhaust. Some of of us also don't like the loud, manufactured (fake) burbling and backfire sounds from our M40i's when driving in Sport and Sport Plus. Personally, I like the "throaty" exhaust note of the M40i but I don't like any of those sounds I've described above and I would prefer that my M40i not make them.

BMW should provide the capability to control those sounds from the iDrive menu like many other manufacturers do, but they don't and this is frustrating to us. The only way to eliminate those sounds on the M40i is through tuning (it can't be done via coding). It's been widely discussed on here that tuning can void your warranty if discovered by the dealer, and also poses other challenges like having to do the tuning again after any software updates.

Also, none of the X3 diesel models are available in the US.

[Douggie]

Originally Posted by Joker Eh

I love the cold start sound. I do find the start louder when it has been warmed up though.

Yeah I like the sound too, just not before 8am and after 9pm. Lol.

[Blacktemplar]

Originally Posted by Joker Eh

I love the cold start sound. I do find the start louder when it has been warmed up though.

If you stop when warm, then restart within a few minutes you get a little bit of the old pop & burble back. No idea why, but it sounds good....

And I have fuse 218 pulled as well which disables the fake ASD sounds, provided you have the HK sound system, so all the exhaust sounds are natural.

[XxDanoxX]

Originally Posted by TX3M

What's not to understand? Some of us want the features and performance of the M40i but don't like the loud, obnoxious startup noise from the exhaust. Some of of us also don't like the loud, manufactured (fake) burbling and backfire sounds from our M40i's when driving in Sport and Sport Plus. Personally, I like the "throaty" exhaust note of the M40i but I don't like any of those sounds I've described above and I would prefer that my M40i not make them.

BMW should provide the capability to control those sounds from the iDrive menu like many other manufacturers do, but they don't and this is frustrating to us. The only way to eliminate those sounds on the M40i is through tuning (it can't be done via coding). It's been widely discussed on here that tuning can void your warranty if discovered by the dealer, and also poses other challenges like having to do the tuning again after any software updates.

Also, none of the X3 diesel models are available in the US.

Don't you guys have the 30i? - another perfectly good alternative. Again, I still don't understand it. It's a performance car, it comes with performance parts. You can't really be half in and half out with an M Car - it's a ridiculous stance.