[Oembmw]

what parts BESIDES the turbo have you seen cause a siren or whine / turbo noise increase?

Ive searched and seen members report inlet gaskets being an issue (inlet to turbo)

Ive also found one member who installed DPs and his whine was drastically reduced.

any input greatly appreciated.

[Saif2018]

Originally Posted by Oembmw

what parts BESIDES the turbo have you seen cause a siren or whine / turbo noise increase?

Ive searched and seen members report inlet gaskets being an issue (inlet to turbo)

Ive also found one member who installed DPs and his whine was drastically reduced.

any input greatly appreciated.

I'm guessing the louder exhaust noise from downpipes muffles the siren/whine.

Inlets popping off or loose can possibly cause similar sound.

[SixSix]

I've seen a few N54 powered cars with the turbo whine/siren, from my experience the only proper fix is to replace the turbos... Typically the sound seems to come from the thrust washer inside the CHRA being worn out, which causes axial play in the turbine shaft. This excess play causes the compressor wheel to get chewed. This noise means that the journal bearing/thrust washer material or aluminum from the compressor wheel is being chewed away and carried away through the oil or intake boost pipes if the compressor wheel is being damaged. Attached picture below of a bank 2 turbo compressor wheel that made the turbo whine noise.

[Saif2018]

Originally Posted by SixSix

I've seen a few N54 powered cars with the turbo whine/siren, from my experience the only proper fix is to replace the turbos... Typically the sound seems to come from the thrust washer inside the CHRA being worn out, which causes axial play in the turbine shaft. This excess play causes the compressor wheel to get chewed. This noise means that the journal bearing/thrust washer material or aluminum from the compressor wheel is being chewed away and carried away through the oil or intake boost pipes if the compressor wheel is being damaged. Attached picture below of a bank 2 turbo compressor wheel that made the turbo whine noise.

Can you post the picture?

Also driving with the siren/whine issue, can this cause engine damage?

Currently mine has the issue but is boosting fine.

[Tambohamilton]

Recently had the map sensor pop out of the manifold on my m57 330d, causing a massive boost leak...that made the turbo pretty loud!

[ab987]

Originally Posted by SixSix

I've seen a few N54 powered cars with the turbo whine/siren, from my experience the only proper fix is to replace the turbos... Typically the sound seems to come from the thrust washer inside the CHRA being worn out, which causes axial play in the turbine shaft. This excess play causes the compressor wheel to get chewed. This noise means that the journal bearing/thrust washer material or aluminum from the compressor wheel is being chewed away and carried away through the oil or intake boost pipes if the compressor wheel is being damaged. Attached picture below of a bank 2 turbo compressor wheel that made the turbo whine noise.

And even then, it likely won't fix it if you are tuned. I am on my third set of stock turbos, all with the exact same siren (with an overkill break-in, turbos primed of course, no boost at all on stock tune for 100 miles, stock boost for 100 miles, stage 1 for 500 miles, then to stage 2+), with my latest set only being 4 months old. As soon as you overspool them (like running 15psi or more up top) it damages the journal bearing in the CHRA like stated above and causes that siren, none of my sets show any evidence of compressor wheel contact on the housing or wheel. Oil analysis shows no change compared to my stock analysis, but there was a little bit of metal in the filter. You may actually have a siren from compressor wheel contact, but in my experience and the experiences of 2 other local tuned N54s, you either don't tune the car or you have the siren. Any exhaust setup louder than catless DPs/stock catback probably covers it up enough to not hear, though. If you want to mess with higher horsepower levels like you get running high boost up top, be prepared to make warranty claims or get bigger turbos.

[Dave92N54]

I don't buy this. My stock turbos (NEVER replaced), I tuned to stage 1+ at 122k miles. I consistently saw 16-17psi. They never made a siren noise, even when I replaced them at 135k. The rear blew a seal and was smoking though.

[Saif2018]

Originally Posted by Dave92N54

I don't buy this. My stock turbos (NEVER replaced), I tuned to stage 1+ at 122k miles. I consistently saw 16-17psi. They never made a siren noise, even when I replaced them at 135k. The rear blew a seal and was smoking though.

Mine started sirening at low speeds, when I went custom tune at 20psi,

Stage 1+ was fine though, stage 1+ doesn't get anywhere near 16psi up top, need a custom tune for that.

My stock turbos still boosting fine at about 20psi peak tapering off to about 16psi. No smoke yet but going through like 1 litre of oil about 4-5k miles so only matter of time before I kill the turbos lol. Couldn't find any oil leaks, had pretty much all gaskets and seals done.

[Saif2018]

Originally Posted by ab987

And even then, it likely won't fix it if you are tuned. I am on my third set of stock turbos, all with the exact same siren (with an overkill break-in, turbos primed of course, no boost at all on stock tune for 100 miles, stock boost for 100 miles, stage 1 for 500 miles, then to stage 2+), with my latest set only being 4 months old. As soon as you overspool them (like running 15psi or more up top) it damages the journal bearing in the CHRA like stated above and causes that siren, none of my sets show any evidence of compressor wheel contact on the housing or wheel. Oil analysis shows no change compared to my stock analysis, but there was a little bit of metal in the filter. You may actually have a siren from compressor wheel contact, but in my experience and the experiences of 2 other local tuned N54s, you either don't tune the car or you have the siren. Any exhaust setup louder than catless DPs/stock catback probably covers it up enough to not hear, though. If you want to mess with higher horsepower levels like you get running high boost up top, be prepared to make warranty claims or get bigger turbos.

That sounds exactly like when it happened to me, you reckon any possibility of engine damage from running the turbos with siren sounding?

[Dave92N54]

Originally Posted by Saif2018

Mine started sirening at low speeds, when I went custom tune at 20psi,

Stage 1+ was fine though, stage 1+ doesn't get anywhere near 16psi up top, need a custom tune for that.

My stock turbos still boosting fine at about 20psi peak tapering off to about 16psi. No smoke yet but going through like 1 litre of oil about 4-5k miles so only matter of time before I kill the turbos lol. Couldn't find any oil leaks, had pretty much all gaskets and seals done.

Oops... I missed the part where he specified that psi up top. That makes much more sense.

[ab987]

Originally Posted by Saif2018

That sounds exactly like when it happened to me, you reckon any possibility of engine damage from running the turbos with siren sounding?

I haven't really found much more metal in the filter than usual, and oil analysis is clean. That's not to say it's good, but I think you'd have other problems before it did anything to your motor. I noticed it started as soon as I switched to stage 2+. Stage 2 only held 12-13psi but 2+ does 15-16, that seems to be the threshold

[Saif2018]

Originally Posted by ab987

I haven't really found much more metal in the filter than usual, and oil analysis is clean. That's not to say it's good, but I think you'd have other problems before it did anything to your motor. I noticed it started as soon as I switched to stage 2+. Stage 2 only held 12-13psi but 2+ does 15-16, that seems to be the threshold

Thanks for the reply mate. That's good to know.

[Navykiller]

Originally Posted by Oembmw

what parts BESIDES the turbo have you seen cause a siren or whine / turbo noise increase?

Ive searched and seen members report inlet gaskets being an issue (inlet to turbo)

Ive also found one member who installed DPs and his whine was drastically reduced.

any input greatly appreciated.

I heard what I assume to be the whine everyone speaks of, (never heard in person so i have no clue) from my car when I went to drive to work in the morning. Pipes and hoses all seemed in place, but I ordered upgraded turbos anyway. When its time to replace, I will be able to get a better look and confirm what they are. If its not turbo, I wont feel like I have egg on my face because ill have more hp lol.

[Tkent818]

You should post a video of the sound and details about when it happens(rpm's, weather, etc.) I made a similar thread with a video that ended up being a boost leak, stock diverter valve failing combo on brand new upgraded turbos. I got a lot of good advice here and always have but some people were convinced it was the turbos that were 300 miles old only because of their brand. Perform all the checks and tests first and then form you conclusions from the results