High pitch squeal
 

Did a search and came up with a few things but nothing pinpointed. Hearing a very high pitch squeal/ whistle and seems to be coming from rear driver side best I can tell. Seems to only happen when I hit the gas and stops when I lay off. Doesn't matter if ac is on or not and doesn't seem to matter what gear.

From best I can tell it is not the belt as it really seems contained to the driver rear wheel area.

Wheel bearing make high pitch noise?

What else can I do to rule stuff out?

Any help greatly appreciated before I go take it in?

If it's a short squeak i would check to see if the spark plugs are tight.

Does it change pitch with change in speed? Can you hear the squeak parked or does the vehicle need to be rolling?

Its not short. It does change pitch when accelerating and it does not happen when parked and revving...

So here is a video clip of what I believe is the sound. Only happens on acceleration. According to this video it sounds like it has to do with either the intake or throttle as it is happening on the intake side and when I push the gas. BUT when I am driving the noise is there a lot longer. Listen for high pitched chirp when I hit the gas. Thoughts?

Boxster chirp noise - YouTube

I had my engine cover off the other day and I noticed when I hit the gas there was a short whistle during the transition from idle to throttle open. I took a recording, but the sound is very faint (so I can't post it for comparison) but I thought I detected the same sort of whistle in your video when you hit the gas. I can't hear it at all when the engine cover is on, and I never heard it when driving. So I am interested in what comes out from this thread.

Steve

If this squeal is loudest at idle and off-idle transition it could be the AOS failing. When this occurs crankcase vacuum skyrockets and air is pulled by the front crank seal, which makes a squealing sound. Not all AOS' fail with this symptom, and it is rare.

cant hear it at idle...but really when hitting the gas more prevlelant when actually moving in the car than what the video shows as it stays on a lot longer when driving. oddly enough, the brakes are now squealing at low MPH. Brakes cant squeal going faster right? Is that a dumb question...is it possible the brakes are catching on the disc or something? It is not constant...I dont hear it when decelerating.

Also - the AOS was just replaced 300 miles ago along with the IMS bearing you all created! But I do recall hearing this noise prior to the IMS and the AOS getting replaced. My noise is on the driver side and the AOS is on the other side right?

It really seems like it is coming from either the wheel or the air intake best I can tell. The air intake is an EVOMS if that matters. No, I didnt put that in...the PO did.

Then again - on my first boxster I put the fabspeed exhaust on and was convinced a noise I was hearing was the belt when actually it was one of the mufflers rubbing the heat shield!

HELP!! I will drive myself nucking futs with this...not to mention my poor wife.

Anymore thoughts???

On mine it is like a quick "whooshp" when I hit the gas. it does not persist, it is only when I initially hit the gas. So it sounds like it might be a different thing. Good luck, I will be watching this thread with you.

Steve

Did you ever figure out what the noise was?

The squeal, if the car is sitting still, has to be one of two things. Something slipping on the belt or air being sucked in. If you have discontected the belt and it's gone then you need to check each part on the drive. If it still squealing then it's air being sucked in. My AOS failed slowly, had the squealing when engine warmed up...very loud as it got hotter. Decided to remove oil cap when engine running and could not...bad AOS.

This would be a good test on direction to go if the AOS is suspected and the symptom is easily replicated ...

wonder if the OP found out what it was..

Earth to Trimer. Did you ever find out what the noise was? Inquiring minds want to know!

I think my similar noise (from earlier in the thread) was just the sound of the air whistling through the throttle body. I am curious to see what Trimer's issue was too in case I have the same noise in the future.

I chalked it up to air coming through the cold air intake...OR it was something that needed greased. I a, going with intake air as that is where it was coming from. Just annoying but only with top down! Ps AOS is new and was doing it before that...