johnmiller-
Curious about your response. I noticed that all 74 of your posts are within the last 24 hrs. Would you like to elaborate on your response? All of the threads about honking DVs point to faulty/leaky operation. Thanks CALH4289

 

Just noticed exactly the same behavior described above. Today was the 1st day I noticed this, and I've been running the same 710N diverter valves since November (with a EPL tune + exhaust, otherwise stock).

Not sure if this just started happening or if I just didn't notice it before (today was the first really warm day of the year, so I was driving around with my windows open.)

As an additional data points:
1 - the sound seems to only be there under low boost (as described above.)
2 - I had the engine RPM's between 3.5k and 6k when I heard it (correlated with picking up boost under mild/moderate acceleration and late shifting.)
3 - When I give it more gas, the boost builds up just as always, and I don't hear anything (not sure if that is just because the engine noise over takes.)
4 - I'm also not making any less max boos than before.

Just wanted to check-in to see if this is accepted as the "normal" behavior, or if I should be doing more troubleshooting.

 

I've had failing stock dv's and honking is the best way to describe the sound as they fail.
I currently have EvoMS dv's and they make no noise and seemingly work as they should.
I would think if the dv's are working properly? They won't "honk" at all.

 

The sound I'm describing is more of a constant "hmm" that persists while I keep the rpm up, as opposed to the distinct single "honk" that I've heard on others' videos that seems to happen when you let off the gas...

Perhaps I'm just in denial in not wanting to believe that my new diverter valves would have gone "bad" in 2k miles and 6months under regular street driving (zero track time.)

 

"hmm"(?).. i don't know what that sounds like, and i'm not being "cute". the only solace i can offer is if they have gone "bad" already?! it's nothing you've done. i would only concern myself with performance, or lack thereof. no lack? no foul.

they honk on full boost, in my limited experience with them. i won't repeat my joke about being once followed south,.. on a long drive..only to find they were "enticed"... possibly canadian, but who really knows for sure.

never mind

 

I went for another drive to see if I could reproduce this, and I'm starting to think that this has nothing to do with boost, and everything to do with the RPMs. On more careful listening, the sounds is more mechanical in nature--like the sounds of gears whirring [more like straight cut gears :-) ]. As I build up the RPM's slow and steady on 1st gear, at right around 4k, I feel like the mechanical sound of the drive train gets notable louder/different (easiest to notice in 1st and 2nd gears, as wind-noise, etc. are lower.) This appears to be true whether or not I'm holding the RPM's steady at ~4k or if I'm increasing/decreasing the RPMs. I can hear it most distinctly when driving next to a tall cement barrier (or wall), with my windows open so that the sound gets reflected back in.


All that said, I'm beginning to wonder if this is just "what our cars sound like"... This is the first time sine I've owned the car that the weather has been nice and warm and I've spent significant time tooling around with the windows open (I verified that with the windows closed it is much harder to hear the sound I'm describing.) Anybody else have similar experiences with potential drivetrain sounds that vary by RPM?

 

what you describe sounds like i would describe the difference btw stock and semi solid/solid motor mounts. you feel everything, whereas before, you didn't. which probably still won't help you because you may have stock stuff and are in fact "learning" the car. if the car is new to you? and you're just experiencing it with open windows whatever.. maybe you are just getting used to it. so, if it ain't broke, just drive it. at 4k and above? you're gonna hear stuff. good stuff. normal.

 

My new 710s make exact same partial throttle 3500rpm honk. The old ones didn't but I put these in 'proactively'. Everything seems fine except the noise so I'm not really sure what to think on these really. ...

 

Hey Larry

Just curious, why would you remove the Forge units for the 710s?

IMO the forge ones work great.

 

I put the Forge units back in and all is quiet again. It was not my idea to change them, the shop did it without asking me.

 

Sorry to revive this thread...

I have the same issue. The only way I can describe it is if you blew air over the top of a milk jug. It's a constant sound at about .1 - .3 bar and goes away when I let off the gas (although I can hear it taper off sometimes...it doesn't completely cease). My 710's were doing this from day 1, and my stock DV's also were also which is what prompted me to replace them with the 710's. Leads me to believe it is something else. There are a lot of check valves and such in the area of the DVs. Is it possible it is one of them?

 

it's not possible to "hear" a leaking check valve unless you're pressure testing and then it will "hiss" as you hear the air escaping. do you happen to know when you changed the dv's if they were older 710a? or 710n? the more robust ( newer? ) version. not that that would make a difference re that "whistling"..

is it possible you are hearing the power steering reservoir whistle of the valve that goes bad? if it's that, it occurs when the engine is HOT and it stops whistling when the clutch is engaged. just offering that as a possibility. most cars this age have had that ps reservoir replaced by now. but it does resemble the sound you described, a bit.