What is this noise!? We need a conclusion

[onebadmofo]

Had exactly the same sound from my car:


After I swapped to RB's the stock turbos had NO play and I was burning NO oil so it's safe to assume it's normal.


Now here's my video with BAD turbo. It had a lot of both lateral and longitudinal play.

[rudypoochris]

It definitely is not a normal sound regardless of play. I am pretty sure it is the journal/thrust bearing being damaged. Is it going to blow up, probably not, is it going to get worse at the boost levels that are being run, of course. Eventually you will consume oil and it will get louder, when that is is up in the air. Maybe @VargasTurboTech can tune in. If I am wrong I I'll run 19+ psi tomorrow lol.

[rudypoochris]

@VargasTurboTech hey can you chime in on this noise?

[rudypoochris]

From Vargas on the other forum, pretty much exactly what I said, but the cause is not what I expected. It isn't cooked bearings making the noise, its the cooked bearings allowing the compressor wheel to contact the housing:

Originally Posted by Vargasturbotech
Turbos should not I repeat not make that noise, a whistle is 100% normal and with less restrictive exhaust you will hear it more. With a siren or as its called turbo howl your turbos are well on there way to going out. The noise is caused by excessive play in the center section, either in the journal bearings radial play or in the thrust axial play, usually its a combo of both. This allows defelction under boost as the exhaust imparts force on the turbine wheel, the excessive play allows the compressor wheel to actually slightly contact the compressor housing causing metal to metal contact and this noise. Once this occurs it actually starts to machine away the blades of the compressor wheel a little at a time and it will eventually throw itself out of balance, take out the piston rings and everything else with it, and you will start smoking badly. Another thing I have seen with stock turbos is, the turbine side piston ring allowed excessive oil to escape past, which gets under the heat shield and from the extreme heat turns into carbon and as this builds up under the heat shield it pushes the back of the heat shield into the back of the turbine wheel, this can also cause this noise with the same results. Bottom line, turbos are on the way out, next thing in the time line is smoke. Hope this helps.

[E90Company]

Little update for you all. Siren noise has been getting louder and is now almost the same volume warm as it is cold. I have catless downpipes installed as well and that amplifies it even more. Still no smoke other than startup white smoke which I think is condensation. It goes away once the car warms up.

Here is a new video. Car is completely warmed up.


Any thoughts?

[vasillalov]

Any thoughts?

Dude, I think it's pretty definitive by now. If you've not gotten it by now here it is bluntly:

START SAVING FOR NEW TURBOS!

What do you expect us to say?!... ...that a sound which you describe as developed itself over time and has grown louder is normal and you have nothing to worry about?... Come one now, use some common sense.

Do yourself a favor: go put a deposit for some nice RB's or Vargas turbos. If you can't spend this much money, then buy some OEM units, lower your boost a little and continue enjoying your car.

[nafoo]

Dude, I think it's pretty definitive by now. If you've not gotten it by now here it is bluntly:

START SAVING FOR NEW TURBOS!

What do you expect us to say?!... ...that a sound which you describe as developed itself over time and has grown louder is normal and you have nothing to worry about?... Come one now, use some common sense.

Do yourself a favor: go put a deposit for some nice RB's or Vargas turbos. If you can't spend this much money, then buy some OEM units, lower your boost a little and continue enjoying your car.

Keeping it real.

[Itsbrokeagain]

Keeping it real.

^ this lol

[E90Company]

Alright guys lol

[Legionofboom]

[ihc95]

Unfortunately my car started making this siren noise last week. It has gotten louder each day. Also the car feels down on power. I don't even know if its worth taking it to the dealer. My car has 77k so maybe I can see if they can replace the turbos under the 8yr/82k mile warranty for the turbos. But thats a long shot since the warranty is mainly for the wastegate rattle.

Another interesting note, my car doesnt make the siren noise while revving the engine in park, only when under load (moving).

[E90Company]

Unfortunately my car started making this siren noise last week. It has gotten louder each day. Also the car feels down on power. I don't even know if its worth taking it to the dealer. My car has 77k so maybe I can see if they can replace the turbos under the 8yr/82k mile warranty for the turbos. But thats a long shot since the warranty is mainly for the wastegate rattle.

Another interesting note, my car doesnt make the siren noise while revving the engine in park, only when under load (moving).

If you actually have this issue, it should make the noise while revving. You won't hear it as much with the stock downpipes on the car though. Floor the gas and let off at 4k in neutral, you should hear it. You need to get the turbo spinning. Does your car do it when warm/cold? Did you see the video I posted a couple posts above?

Honestly mine has been doing it for quite awhile now and it's pretty loud cold and warm. When @BoostAddict put the downpipes on he said there was no shaft play, and I don't notice any smoke. I don't know what the cause of it is still or if it's something to worry about, but I have been fine so far. I only have 20,000 miles and it's doing it. I also met with a 1M owner the other day and his turbos did the same noise at 4k miles.

[themyst]

Every single one of my turbos across two N54s and a set of rbs sounded like that.

[E90Company]

Every single one of my turbos across two N54s and a set of rbs sounded like that.

Really? Just like the video I posted a few above? That video is fully warmed up. Any smoke/performance loss?

[themyst]

Really? Just like the video I posted a few above? That video is fully warmed up. Any smoke/performance loss?

yes, yes, even worse in one case, and no, except on the RBs where it's normal/no.

[Ferruccio]

As far as I can tell, I have had this noise for as long as I have had the car, for about 25k miles. It became much more apparent when I switched to DCI's. The sound completely goes away once the engine partially warms up. If I save up and swap for RB's (which I'm totally considering) How much would I have to drastically change the engine tune? Could I basically keep the same tune?

[ihc95]

@E90Company You don't have any performance loss? My car seems to have no midrange anymore although I have been too scared to go WOT so I can't comment on the high rpm performance. The low end grunt seems to still be somewhat there so it seems the turbos just give up once it hits a certain PSI.

[E90Company]

@E90Company You don't have any performance loss? My car seems to have no midrange anymore although I have been too scared to go WOT so I can't comment on the high rpm performance. The low end grunt seems to still be somewhat there so it seems the turbos just give up once it hits a certain PSI.

I don't think I have any performance loss. Yet again I don't really know since it's been so long since my turbos didn't do this.

[5hourenergy]

hahaha

[rudypoochris]

Its the sound of your shoes

[E90Company]

All jokes aside, there's clearly an issue with the turbos. I get that. If these pop and I need new ones so be it. I don't really care. I just want to know from at least one knowledgeable member on Bimmerboost or Rob Beck/Vargas to give me their reasoning why these turbos make this sound.

Why do some cars make the sound and others dont? What causes it? What makes some of the volume go away when warmed up but still be there? Shaft play theory dousn't make sense with this.

@VargasTurboTech , you said it's due to shaft play. When the downpipes were put in the turbos were checked for shaft play and there is absolutely zero movement. I have no smoke. No performance issues. Only this howl that is very loud when cold and still very loud when warm (per video) Why?

Also per @themyst , he has this noise that developed on RB turbos. Clearly he dousn't have any shaft play issues with his, so why this developed noise? There's got to be an answer to this.

As of right now, my best guess is that the actual turbine wheel itself, being as small as they are, one of the blades actually warps during a high heat, high boost condition. This very minute warping of one of the blades causes a disturbance in airflow that will create this noise. I have also noticed from users posting on this forum and the other forum that have this noise, alot of them ran high boost (15psi+) for extended periods on the stock downpipes, which only creates more heat and somewhat backs up my theory. I also think this shouldn't affect performance at all or lead to smoking down the line, which isn't related to this noise. Let me know what you think. Please.

Thanks,
Nick

[rudypoochris]

Nah, my best guess, besides contact, is bearing wear. Pop those out and check for scoring.

[E90Company]

Nah, my best guess, besides contact, is bearing wear. Pop those out and check for scoring.

Probably more correct

[TLO03]

Little update for you all. Siren noise has been getting louder and is now almost the same volume warm as it is cold. I have catless downpipes installed as well and that amplifies it even more. Still no smoke other than startup white smoke which I think is condensation. It goes away once the car warms up.

Here is a new video. Car is completely warmed up.
http://www.youtube.com/watch?v=aYS6h...yer_detailpage

Any thoughts?

Dood I don't believe it, my turbo makes the same noise not quite a siren more like a chirpy flutter and I couldn't find the sound anywhere . The only difference is my turbo is on my allroad and there's a lot of oil in the I/C piping. I've told it was a seal or something.

and btw I did follow my previous advice I jacked up the boost and bought new turbs but haven't blown yet..

[E90Company]

Dood I don't believe it, my turbo makes the same noise not quite a siren more like a chirpy flutter and I couldn't find the sound anywhere . The only difference is my turbo is on my allroad and there's a lot of oil in the I/C piping. I've told it was a seal or something.

and btw I did follow my previous advice I jacked up the boost and bought new turbs but haven't blown yet..

It's so strange this noise