X47 noise diagnosis ideas? Subtle F# note....

[jeff]

What's up people!

Wondered if any had this issue and can report, I'd appreciate it!

So last weekend was put a X47/WGA/Cobb DP/ported manny/colder plugs on my car...I'm in the tuning process. Car feels great even on 2nd revision. Super happy!

Now, I have 4 new noises, the fourth of which is something I haven't read about so I'm wondering if it's abnormal:

NOISE 1 = more intake noise, to be expected...
NOISE 2 = the X47 whistle, loudish and obvious, around 2500rpms, this has been talked of much and is to be expected with the X47...
NOISE 3 = more exhaust, to be expected...
NOISE 4 = a very subtle but nearly always there whistle...

Noise 4 is the one I'm asking about. Could be turbo spool but it doesn't increase or decrease (rise or fall in pitch), it just appears and disappears. It appears when the car is still or driving. I can coast and it's there, no throttle. It is most notable when very slightly engaging the throttle. I've heard it in all gears, moreso with the windows down.

I checked the hoses/intake/etc. for any leak and didn't see anything, though I didn't go too far or remove the intake. My CP-E airbox has a slight gap in the top cover, I put some painters tape around it, but noise is still there. I thought maybe it was the cowl or something like that, but if it were something of the structural nature it would always be there rather than come and go. So I think it has to do with engine/exhaust/hardware.

Could be turbo, or manifold, or DP, or WGA, or none of the above. I'm stumped.

After hearing it for hours, I went to my piano, being a musician, and as I suspected it is an F# note, for what it's worth! I tried to get a sound clip but the phone won't pick it up. But whistle an F# note and that's the exact sound. In fact, it sounds like there is a little person under my hood whistling gently, about that volume.

I asked my tuner if he saw anything in the datalogs that indicated a leak/issue, he said NO!

*****
Any ideas?



Thanks in advance!

 

[shouldbeasy]

Try to get a video! (Edit - just read a you did try... dang! Maybe a different camera if you have one? )

But really, mine makes all sorts of turbo noises - my stock intake lets the whistle through more than say my friends CPE intake which you hear more intake noises and air sounds.

Are you very sensitive to the noise changes?

And lastly, if it doesn't affect the car's performance along with nothing showing in the logs, call it good! Just check fluid levels and all that - oh, did you pressure up the turbo before starting the car? I have a video that's accumulating a good number of views showing how to do it.

 

[letitreign]

At the very least you can rule out the CP-E airbox, mine's not air tight either and I'm not experiencing this noise.

 

[CanadianGuy]

Are you sure it is not you going "WEEEEEEE!!!!!!!" ? I would in your setup.

To be fair (i was bored before I proceed with this) You have new parts they make new sounds. My refrigerator manual started with "your new appliance will sound different than your old one. This is normal". Not saying you do or do not have a problem but too many no variables. Other things to check. sound the same cold engine or hot engine? Down shifting (pulling vaccum instead of boost)? in gear not in gear?

 

[jeff]

Try to get a video! (Edit - just read a you did try... dang! Maybe a different camera if you have one? )

But really, mine makes all sorts of turbo noises - my stock intake lets the whistle through more than say my friends CPE intake which you hear more intake noises and air sounds.

Are you very sensitive to the noise changes?

And lastly, if it doesn't affect the car's performance along with nothing showing in the logs, call it good! Just check fluid levels and all that - oh, did you pressure up the turbo before starting the car? I have a video that's accumulating a good number of views showing how to do it.

Thanks for the thoughts. Yes, turbo was installed correctly! As for sensitive to noise changes, the answer is YES. I expected some, just never read about this one so I want to make sure all is well and possibly identify the source. I use my radio/audio system 1% of the time...my car is my sanctuary and about the only place I get peace and quiet, so I tend to drive around alot thinking and praying and musing on life. Also I'm a musician. So the ears are always on high alert. Maybe too much!

At the very least you can rule out the CP-E airbox, mine's not air tight either and I'm not experiencing this noise.

OK thanks!

Are you sure it is not you going "WEEEEEEE!!!!!!!" ? I would in your setup.

To be fair (i was bored before I proceed with this) You have new parts they make new sounds. My refrigerator manual started with "your new appliance will sound different than your old one. This is normal". Not saying you do or do not have a problem but too many no variables. Other things to check. sound the same cold engine or hot engine? Down shifting (pulling vaccum instead of boost)? in gear not in gear?

The WEEEEEEEEEEEEE!!!!!!!!!! in my head doesn't come out of my mouth too much because I'm in analysis mode. Haha very funny though!

The thing about me is I do extensive research and analyze everything far more than most people. So as I mentioned new noises #1-3 were to be expected, but not #4. I'm not a person who can say "the car runs great, no worries!". I want to know because it bothers me and if it can be eliminated I'll try to find a way. If it's normal, fine. Just want to know if it's normal. Since it is so present and I haven't read of this one yet, I think it is abnormal. Plus it's 97 here; if it's this noticeable now, I am sure it will be much more present when it is 20 in a few months.

To your (very good) questions - noise is same hot and cold. Down shift or up shift, it's there. It's there coasting in neutral, when I'm still and revving the engine not moving, both when in gear and out of gear. I can be sitting there in my driveway not moving, gently rev the engine, and the noise comes and goes with the rev. But then again, I can be coasting along with zero throttle and the noise is there, so it doesn't seem as attached to the revs.

Thanks again for ideas....my friend Daniel is gonna look at the car with me tomorrow, he's a whiz, maybe he will have some 411...

 

[Quisp]

Stock diverter, GFB, ?

 

[BoostBumps]

Are you sure it is not you going "WEEEEEEE!!!!!!!" ? I would in your setup.

WEEEEEEEEEEE!!!!!

[video=youtube;XMTfHbc788Y]https://www.youtube.com/watch?v=XMTfHbc788Y[/video]

 

[jeff]

Stock diverter, GFB, ?

Stocker. Talk to me....

 

[CanadianGuy]

Stocker. Talk to me....

Spring can weaken overtime and not close the valve. You would see something on the ap when not pulling boost. My next question is if you hear it at idle where/what side of the engine is it comming from?

 

[Quisp]

Stocker. Talk to me....

Mine would noticeably leak at 25lbs till I went GFB.

 

[jeff]

Stock diverter, GFB, ?

Spring can weaken overtime and not close the valve. You would see something on the ap when not pulling boost. My next question is if you hear it at idle where/what side of the engine is it comming from?

To my chagrin I did not look into an upgraded diverter valve when getting my turbo swap parts.......when you say I'd see something on the AP, which monitor do I need to look at? When I said I heard it at idle I didn't mean when the car is sitting there still, but the noise IS there when sitting still and gently revving, and also when coasting with no throttle input. Sounds like it's coming from the driver's side of the engine but I can't verify that since my head isn't under there!

Now, I looked into the GFB piece and found this video....it only says the sound is gone so you can't hear what it did sound like....however it perfectly describes what I am experiencing as "low rev venting"...

https://www.youtube.com/watch?v=0Fsc8R6Eqx4

 

[CanadianGuy]

Look at the boost measurement. When idle it should be near -10. If higher than -9 diverter valve spring is weaken.

 

[jeff]

Look at the boost measurement. When idle it should be near -10. If higher than -9 diverter valve spring is weaken.

Just cranked him up, was -9.8 for a few seconds. Gave it a little rev, it settled at -10.2 for a few minutes till I shut it off.

 

[CanadianGuy]

Just cranked him up, was -9.8 for a few seconds. Gave it a little rev, it settled at -10.2 for a few minutes till I shut it off.

That's good. Guess you need the two head approach one in the driver seat hitting the gas and one in the engine listening and poking.

 

[jeff]

That's good. Guess you need the two head approach one in the driver seat hitting the gas and one in the engine listening and poking.

Haha. I went ahead and ordered a GFB DV+ per [MENTION=3955]Quisp[/MENTION]. Couldn't hurt, with the upgrade I just did i should have anyway for other reasons. We will see if that fixes this noise.

 

[CanadianGuy]

Haha. I went ahead and ordered a GFB DV+ per [MENTION=3955]Quisp[/MENTION]. Couldn't hurt, with the upgrade I just did i should have anyway for other reasons. We will see if that fixes this noise.

Now with even more boost! It's a good upgrade.

 

[WhiteST]

I'm wondering if this is just a normal sound from the turbo. I think I may have the same sound on my x47. Went from 2jr intake to stock, still hear it.

 

[jeff]

OK UPDATE...

Just installed the GFB DV+, noise is gone gone gone.

Ahhhhhhh......................................



Conclusion: Upgraded turbo either caused or increased volume of low rev venting which made annoying Gb (piano note) whistle. Upgraded diverter valve is the solution if you want to eliminate this noise, and is a good mod to have in general.

Hope someone finds this thread and is helped in the future.