[lolbrother]

So a while back I installed a CAI and a NB+ diverter valve on my N20 328i. It ran really good for about 2 months, then I started hearing this whistling noise. At first I thought it was my charge pipe, so I took it out, looked at it and found nothing was amiss. I decided to change it out anyway, since it was the only plastic piece in my intake. No change in sound. Now I'm wondering if it is a vacuum leak or my diverter valve somehow started leaking. Video included of whistling when accelerating past 75%, then the last acceleration was at about 50%. Please let me know what this could be https://youtube.com/shorts/UAxtV6_IXgg?feature=share

[cedaj]

most definitely a leak somewhere. Sounds more like an intake leak, might wanna check if your CAI is on properly or if your turbo inlet isn't broken

[jtalweezy]

That does sound like a leak. You say it started randomly after about 2 months?

I have a B46 and they do not have any DV upgrades out for it yet, but does it have any kind of seal that is used with the DV you purchased?

I know it sounds counter intuitive, but maybe put the OEM parts back on and see if it disappears?

You already ruled out the Charge Pipe, so i would leave that alone, unless of course the virton (spelling?) o ring is maybe folded in some way allowed air to enter at the turbo inlet or around the charge pipe seal?

Just thinking out loud here.

[lolbrother]

Originally Posted by cedaj

most definitely a leak somewhere. Sounds more like an intake leak, might wanna check if your CAI is on properly or if your turbo inlet isn't broken

I greased every part of my CAI when I replaced the charge pipe, and since all the pieces are metal I doubt there's somehow a hole in one of them. I'm going to try to smoke test it next, to see where the leak could be

[lolbrother]

Originally Posted by jtalweezy

That does sound like a leak. You say it started randomly after about 2 months?

I have a B46 and they do not have any DV upgrades out for it yet, but does it have any kind of seal that is used with the DV you purchased?

I know it sounds counter intuitive, but maybe put the OEM parts back on and see if it disappears?

You already ruled out the Charge Pipe, so i would leave that alone, unless of course the virton (spelling?) o ring is maybe folded in some way allowed air to enter at the turbo inlet or around the charge pipe seal?

Just thinking out loud here.

The DV has a seal which I did grease prior to installation, so I doubt the leak is there but there might be a small chance. The thing is putting the new one on was incredibly difficult (like 5 hour job) and I managed to snap the old one in the process of removing it. If I ran through all the other options, I will find a OEM diverter valve and put it back on.

As for the seal, I'm not quite sure what you could be talking about, but the new charge pipe came with a new seal that goes into the turbo. I did grease all around the seal before installation.

[jtalweezy]

Hmm. This is interesting. I would really like to see this in person. Do you have any extended acceleration videos? 0-60 WOT prefferably?

[lolbrother]

Originally Posted by jtalweezy

Hmm. This is interesting. I would really like to see this in person. Do you have any extended acceleration videos? 0-60 WOT prefferably?

So the whistling happens regardless of how fast I'm going, I could be going 3km/h in the parking lot and as soon as I press on the gas past 75% it whistles. But I think I know of what you're asking, so I'll explain a bit before I can get a video later on. It whistles pretty loud initially at the starts, then starts to die off. But when it changes gear, it starts whistling loud again, and dies off.

[lolbrother]

Originally Posted by jtalweezy

Hmm. This is interesting. I would really like to see this in person. Do you have any extended acceleration videos? 0-60 WOT prefferably?

https://youtube.com/shorts/ZxPU6FHA0lU?feature=share

Here is the video of 0-60 with my foot all the way down. I had the windows up because of the wind noises. It stays whistling as long as my foot is down

[atpenney]

Originally Posted by lolbrother

https://youtube.com/shorts/ZxPU6FHA0lU?feature=share

Here is the video of 0-60 with my foot all the way down. I had the windows up because of the wind noises. It stays whistling as long as my foot is down

I have the exact same noise when WOT. I have stock intake, stock DV. Only became noticeable after I tuned it and became even louder after I installed my downpipe.

https://youtube.com/shorts/b_QGfg5WebI?feature=share

[jtalweezy]

This guy had a similar whine, I can hear although it is not as pronounce as yours.

https://f30.bimmerpost.com/forums/sh....php?t=1595918

If this IS the timing chain in your car, I would take it to a local BMW shop and see if it is covered under warranty if it is indeed the timing chain/tensioner.

[lolbrother]

Originally Posted by jtalweezy

This guy had a similar whine, I can hear although it is not as pronounce as yours.

https://f30.bimmerpost.com/forums/sh....php?t=1595918

If this IS the timing chain in your car, I would take it to a local BMW shop and see if it is covered under warranty if it is indeed the timing chain/tensioner.

You can only hear the sound in gear, not while parked. If I put in drive and press hard on the brakes, you can hear it whistling. I have no clue why it only whistles in gear, so that's why I assumed it was an air leak of some sort. My next step is either a boost leak check and/or smoke test

[lolbrother]

Originally Posted by atpenney

I have the exact same noise when WOT. I have stock intake, stock DV. Only became noticeable after I tuned it and became even louder after I installed my downpipe.

https://youtube.com/shorts/b_QGfg5WebI?feature=share

Have you managed to find a fix for it?

[atpenney]

Originally Posted by lolbrother

Have you managed to find a fix for it?

Took it to a shop today and was told my turbo needs to be replaced and it cannot hold adequate pressure. The tech told me turbos are like brake pads, they don't last forever.

My options are to buy either a new or refurbished turbo, or sell the car entirely before the turbo is completely toast. I am leaning towards buying a 335 or 340 and selling my car.

Pretty disappointed since it is a 2016 n26 with less than 100k kilometres.

[atpenney]

I was quoted $2500CAD for a new turbo and $1300 for a refurbished one. What do you guys recommend? I have a very desirable spec, BSM with Dakota red, m sport, all options. I am thinking I will be looking at quite a price jump to get into a 335 or 340 with similar spec to my 328.

[Slick_FThirty]

Originally Posted by atpenney

I was quoted $2500CAD for a new turbo and $1300 for a refurbished one. What do you guys recommend? I have a very desirable spec, BSM with Dakota red, m sport, all options. I am thinking I will be looking at quite a price jump to get into a 335 or 340 with similar spec to my 328.

$2500 for a new turbo, fully installed is a really good price. You could also rebuild your turbo. All that needs to be replaced generally is the "cartridge" for these Mitsubishi turbos. Some have even DIYed the cartridge replacement.

Just make sure they replace both oil supply lines. I would also recommend replacing the coolant lines as well.

I would go for the new turbo, especially at that amazing price for both part and install, as the refurbished one will have pre-existing wear on various components. With that being said, I've heard of good stories with refurbished ones. Again, with the Mitsubishi turbos, usually it's just the cartridge that is replaced. If you can't afford the new turbo, then I would go for the refurbished.