[theOkilla]

Hello,

My car has felt very slow and has been well under the boost target for a while. I’m running a custom tune with pure stage 2 high flow turbos, FBO, etc.

https://datazap.me/u/theokilla/n54-p...og=0&data=3-21

Here’s a link to a log I did today. I haven’t been able to find any obvious boost leaks (even on the intercooler where it’s leaked before) but can’t find any issues. I’m at 110k Miles and have the original boost solenoids and VANOS solenoids still.

When I accelerate the car sounds like it has a loud whining sound to it, almost like a bad belt or alternator. No visible wear to the serpentine belt and I don’t see any leaking oil from my oil filter housing gasket. The car sounds more supercharged than it does turbocharged right now.



VIDEO OF SOUND
https://youtube.com/shorts/jz0XDz0AZog?feature=share


UPDATE - boost solenoids did not help at all, still at 7psi. I replaced both of them.

[Bimmer_Bro]

Originally Posted by theOkilla

Hello,

My car has felt very slow and has been well under the boost target for a while. I’m running a custom tune with pure stage 2 high flow turbos, FBO, etc.

https://datazap.me/u/theokilla/n54-p...&data=3-21

Here’s a link to a log I did today. I haven’t been able to find any obvious boost leaks (even on the intercooler where it’s leaked before) but can’t find any issues. I’m at 110k Miles and have the original boost solenoids and VANOS solenoids still.

When I accelerate the car sounds like it has a loud whining sound to it, almost like a bad belt or alternator. No visible wear to the serpentine belt and I don’t see any leaking oil from my oil filter housing gasket. The car sounds more supercharged than it does turbocharged right now.

I would start with boost solenoids. Those are very old if they are original. It's a common maintenance item and it could very well solve your issue. Do vacuum lines as well if you haven't already.

[theOkilla]

Originally Posted by Bimmer_Bro

I would start with boost solenoids. Those are very old if they are original. It's a common maintenance item and it could very well solve your issue. Do vacuum lines as well if you haven't already.

Okay, I replaced every vacuum line with nicer high heat resistant silicone ones and I don’t see any issues with those. I have owned the car since 85k miles and don’t see boost solenoids in the service history. I’m 90% sure they’re original. I ordered two new ones so I can try those first.

[Bimmer_Bro]

Originally Posted by theOkilla

Okay, I replaced every vacuum line with nicer high heat resistant silicone ones and I don’t see any issues with those. I have owned the car since 85k miles and don’t see boost solenoids in the service history. I’m 90% sure they’re original. I ordered two new ones so I can try those first.

It's a good place to start. Would be hard to diagnose anything else until you can rule those out. Report back once installed.

[theOkilla]

Do you ever make a whining sound when they go bad? It’s gotten pretty loud on acceleration

[Saif2018]

Originally Posted by theOkilla

Do you ever make a whining sound when they go bad? It’s gotten pretty loud on acceleration

It does happen, especially on stock turbos near 20psi and driven hard.

[Saif2018]

Originally Posted by theOkilla

Hello,

My car has felt very slow and has been well under the boost target for a while. I’m running a custom tune with pure stage 2 high flow turbos, FBO, etc.

https://datazap.me/u/theokilla/n54-p...og=0&data=3-21

Here’s a link to a log I did today. I haven’t been able to find any obvious boost leaks (even on the intercooler where it’s leaked before) but can’t find any issues. I’m at 110k Miles and have the original boost solenoids and VANOS solenoids still.

When I accelerate the car sounds like it has a loud whining sound to it, almost like a bad belt or alternator. No visible wear to the serpentine belt and I don’t see any leaking oil from my oil filter housing gasket. The car sounds more supercharged than it does turbocharged right now.

Doesn't look like a boost leak, usually WG duty cycles climbs rapidly when it's trying to meet target. Hopefully your boost solenoids solve your problem otherwise you may have to pull the turbos and have them inspected

[theOkilla]

Originally Posted by Saif2018

Doesn't look like a boost leak, usually WG duty cycles climbs rapidly when it's trying to meet target. Hopefully your boost solenoids solve your problem otherwise you may have to pull the turbos and have them inspected

Okay, sure hope it’s not the turbos. They are Pure Stage 2 high flows with only 10,000 miles on them.

Thanks for all the help guys

[theOkilla]

Originally Posted by Saif2018

It does happen, especially on stock turbos near 20psi and driven hard.

I’m running Pure turbos but have definitely ran the car very hard since I have owned it. Bought at 85k miles with original solenoids

[Saif2018]

Originally Posted by theOkilla

I’m running Pure turbos but have definitely ran the car very hard since I have owned it. Bought at 85k miles with original solenoids

What psi did you run them?

Pure turbos should be pretty reliable. Have you checked to see if inlets have popped off or come loose?

[theOkilla]

Originally Posted by Saif2018

What psi did you run them?

Pure turbos should be pretty reliable. Have you checked to see if inlets have popped off or come loose?

I’m not running them hard at all - only about 21psi making 500whp on 93.

I did notice that the whining sound is definitely coming from the driver side and it gets louder as the RPM raises

[theOkilla]

https://youtube.com/shorts/jz0XDz0AZog?feature=share


Here’s a video of the sound. I’m not sure if the lack of boost and the whining sound are related.

[Bimmer_Bro]

Originally Posted by theOkilla

https://youtube.com/shorts/jz0XDz0AZog?feature=share


Here’s a video of the sound. I’m not sure if the lack of boost and the whining sound are related.

To me it seems more speed related than turbo noise.
Can this exact sound be replicated when parked and reving in natural? Or only when moving?

[Bimmer_Bro]

Originally Posted by theOkilla

https://youtube.com/shorts/jz0XDz0AZog?feature=share


Here’s a video of the sound. I’m not sure if the lack of boost and the whining sound are related.

Couple other things to check as I don't think it's turbos. The whine follows the Rpm's too much for me to think turbo spool.
Is your AC on while doing this? The AC and alternator bearings are know to whine before the fail.

Also, I want you to open your oil filter cap. Does the filter looked collapsed at all? I read some users hear a whine and it was a bad oil filter. Once replaced the whine was gone.

[Saif2018]

Originally Posted by Bimmer_Bro

To me it seems more speed related than turbo noise.
Can this exact sound be replicated when parked and reving in natural? Or only when moving?

Just heard it, I have to agree, doesn't sound like turbo whine, at least not like mine. I only get the whine at low rpm and it goes away as soon as boost starts to build.

Turbo whine is more like this...

[Saif2018]

Originally Posted by theOkilla

I’m not running them hard at all - only about 21psi making 500whp on 93.

I did notice that the whining sound is definitely coming from the driver side and it gets louder as the RPM raises

Have you asked your tuner?

I would check inlets as they may have come loose but it does sound like something else is causing the whine.

[theOkilla]

Thank you for all the suggestions. I will check all of those things and message my tuner as well.

[theOkilla]

Do you guys suspect the whining noise and lack of boost/power are related or two separate issues?

[theOkilla]

Originally Posted by Bimmer_Bro

Couple other things to check as I don't think it's turbos. The whine follows the Rpm's too much for me to think turbo spool.
Is your AC on while doing this? The AC and alternator bearings are know to whine before the fail.

Also, I want you to open your oil filter cap. Does the filter looked collapsed at all? I read some users hear a whine and it was a bad oil filter. Once replaced the whine was gone.

It still makes the whining sound with the AC completely turned off. I’ll check the oil filter tonight when I get home

[Bimmer_Bro]

Originally Posted by theOkilla

Do you guys suspect the whining noise and lack of boost/power are related or two separate issues?

I think they are separate. The whining does not sounds like turbos at all. The sounds changes evenly with your rpm's and not like turbo spool.

I think boost solenoids may solve your boost issues.

[theOkilla]

Originally Posted by Bimmer_Bro

I think they are separate. The whining does not sounds like turbos at all. The sounds changes evenly with your rpm's and not like turbo spool.

I think boost solenoids may solve your boost issues.

Okay, makes sense. Because the noise stays the same when the AC is off is it safe to assume it’s the serpentine belt/pulleys? I ordered a new belt, pulleys, and an aluminum power steering pulley which I’ll replace when it comes.

[Bimmer_Bro]

Originally Posted by theOkilla

Okay, makes sense. Because the noise stays the same when the AC is off is it safe to assume it’s the serpentine belt/pulleys? I ordered a new belt, pulleys, and an aluminum power steering pulley which I’ll replace when it comes.

You might want to get it narrowed down before throwing more parts at the car. Does it make the same noise when stationary and reving? This will help determine if it's engine or drive train.