High-Pitched Dash Squeal at Speed

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Feb 7, 2021 | 05:23 PM

wigwampro

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From: Los Angeles

High-Pitched Dash Squeal at Speed

Hi Friends,

1986 Porsche 928 Automatic S2 (Euro). At 35mph and over, there is a high pitched squeal coming from the passenger side dash. No change with windows up/down, sunroof open/closed, side view mirrors in/out, stereo on/off, air blower fan on/off or on any settings. Windshield gasket/seal seems good all around. When below 35mph, squeal stops. YouTube link to the video below. I’d love to hear your thoughts and any advice is appreciated.

Last edited by wigwampro; Feb 7, 2021 at 10:00 PM.

Feb 7, 2021 | 06:09 PM

ammonman

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From: NW Arkansas

Check the vacuum line and pod that controls the re-circulation flap in the passenger footwell. Also check the vacuum line to the LH controller behind the kick panel at the right side of the passenger footwell.

Feb 7, 2021 | 06:12 PM

Mrmerlin

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From: Philly PA

AAAH but teach a man how to fish and he will have food for ever,

have fun get to it

https://www.928gt.com/t-wallyhvac.aspx

Last edited by Mrmerlin; Feb 7, 2021 at 06:13 PM.

Feb 7, 2021 | 07:07 PM

SteveG

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From: New York

Quote:

Originally Posted by Mrmerlin

AAAH but teach a man how to fish and he will have food for ever,

have fun get to it

https://www.928gt.com/t-wallyhvac.aspx

OMG, Stan.

Feb 7, 2021 | 07:20 PM

PorKen

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Try the windshield /\ setting. This will bypass most of the vacuum pods.

Feb 7, 2021 | 09:45 PM

wigwampro

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From: Los Angeles

Quote:

Originally Posted by ammonman

I remember one vacuum line on the LH controller. I’ll check that. I started checking all vacuum lines in the center console from the drivers side with the mityvac. Are those the other lines you mention?

Feb 7, 2021 | 09:47 PM

wigwampro

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From: Los Angeles

Quote:

Originally Posted by Mrmerlin

AAAH but teach a man how to fish and he will have food for ever,

have fun get to it

https://www.928gt.com/t-wallyhvac.aspx

Hey Mr Merlin! Thanks for the link. I’ve been diving into this awesome write up for some time now (my A/C is next on my list of things to do). I’m currently going through some of the vacuum checks on the center console, drivers side.

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Feb 7, 2021 | 09:50 PM

Tony

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Ive played a few pranks in my life...

but...sunroof closed?

Feb 7, 2021 | 09:59 PM

#10

wigwampro

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From: Los Angeles

Quote:

Originally Posted by Tony

Ive played a few pranks in my life...

but...sunroof closed?

Good question. I’ll update the post but there is no change with sunroof open or closed.

Last edited by wigwampro; Feb 7, 2021 at 10:20 PM.

Feb 7, 2021 | 10:14 PM

#11

Mrmerlin

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From: Philly PA

put the selector to defrost since this pod is the least used it will probably hold vacuum

Feb 7, 2021 | 10:19 PM

#12

wigwampro

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From: Los Angeles

Quote:

Originally Posted by Mrmerlin

put the selector to defrost since this pod is the least used it will probably hold vacuum

Shouldn’t these pods/diaphragms not be the problem since this issue occurs even while the blower and vents are totally off?

Feb 7, 2021 | 10:32 PM

#13

Mrmerlin

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From: Philly PA

for you to answer that question your going to have to read the link I sent,
then test your pods with a mytivac

Feb 8, 2021 | 12:17 AM

#14

Billu

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From: SW Minnesota

Drive slower. Squealing passenger.

Feb 8, 2021 | 04:23 AM

#15

gazfish

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From: Dublin, Ireland

Have you checked that all your external windshield trim is tight, just tap it with your finger all around to see if it vibrates. Might be acting like a blade of grass in the wind.

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