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Whistle @ 5000rpm cause for alarm?


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It seems like since I did the oil separator I get this whistle a high rpm. Only when she downshifts and jumps to 5000rpm and then the whistle goes away the second it upshifts again and the rpms drop. Never heard that noise before. The transmission fluid is at the proper level. Front diff is a touch high.

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You removed the Intake boot between the Airbox and the throttle body when you did the seperator plate right?

 

Well, it's whistling now from how it's reinstalled. You need to either bed it a bit more, or a bit less.

 

The ridges in that boot act like the ridges in a Elk or Moose call. When you put enough air through it, it whistles.

 

I've seen it on lots of Legacies and Outbacks. We call it the "ghost turbo" whistle.

 

nothing to worry about.....if you don't like it, loosen the clamps on that boot and put a bit more bend in it, or if it's bending now....stragihten it....just move it out of that "sweet spot" where the whistling happens

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I've also seen this exact same scenario with bad power steering pumps. I just replaced one on a '99 OBW that would whine at above 4 grand - sounded like a faint timing belt idler bearing noise or a "ghost turbo" like Gloyale mentioned. Now I just bought a '97 with the same thing going on. Both of these have leaking PS pumps (to varrying degree's) though I don't imagine that's a neccesity for the noise. In both cases the operation of the PS is unaffected - just noisy.

 

GD

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It's easy to tell if it's intkae noise, because it's thorttle related.

 

The whistle will come on a somewhat lower RPMS, if the throttle is wide open and the engine load is high. And right at the point where it begins to whistle, if you dip your foot out of the accelerator, noise goes away, but with a blip back into the throttle, the noise comes back.

 

PS noises I would not think to be affected by throttle and load.

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Not trying to hi-jack.. but on mine you can hear it more in the exhaust (out the tailpipe) than anywhere else.. I'm going to check the intake thingy out tomorrow though. Mine is clearly affected by the load on the engine so I don't *think* it's power steering..

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  • 1 month later...

Have you been able to resolve this?

 

I am getting a similar whistle above 3500 RPM at WOT on my 98LGT.

 

It started after I rebuilt the engine. I did have the entire intake disassembled so maybe it is the boot as Gloyale suggests. I have replaced all the vacuum lines, breather hoses, and most of the clamps.

 

I am getting tired of pulling the intake manifold off and replacing gaskets chasing this :confused:

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Have you been able to resolve this?

 

I am getting a similar whistle above 3500 RPM at WOT on my 98LGT.

 

It started after I rebuilt the engine. I did have the entire intake disassembled so maybe it is the boot as Gloyale suggests. I have replaced all the vacuum lines, breather hoses, and most of the clamps.

 

I am getting tired of pulling the intake manifold off and replacing gaskets chasing this :confused:

 

It's not a "problem", just a noise.

 

There really isn't a need to *fix* it.

 

Try getting the portion of the intake tube with the ridges on it to do a bit more or a bit less of a bend than it currently has.

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Thanks for the info.

 

I thought the tube sticking out the back of the ribbed tube was supposed to compensate for the resonance :confused:

 

I am just annoyed by it. I have done a lot of work on the car this year and everything is good except the whistle.

 

It is getting cold now, so I am not driving with the windows open. I suppose I can ignore it for the winter.

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