UK '91 964 c2 owned for 18mnths..... has always 'squeeled' at high speeds (120mph+) although doesn't sound as if from engine / rear... sounds more like in the dashboard area.... recently had full service and running fab except this goddam noise.... any idea's would be kindly appreciated

thanks

albi

 

Could you have a leaky seal at your windshield, doors or windows? My dad had a truck that would whistle when you drove above 60mph. The solution was to pull shut the vent window in the door or put a nickle under the vent window latch. The proper solution would have been to replace the vent window's rubber seal but the nickle was cheaper. ;-)

 

Have you tried shifting the position of the air-flow sliders a little? Mine whistles at speed if these are both fully to the left (i.e. shut).

 

Dear Albi,
I would certainly agree that the problem may be due to an unsealed windshield using an OEM and not Porsche window seal. The other problem that I can think of is that the fresh air valve is stuck full open. As you increase in speed the valve should be moved towards closed. It will never close fully. Maybe your fresh air servo valve has failed. Just a thought.
Ciao,
Adrian
964C4

 

I know this thread is rather old but I hope to re-open the debate. I have what at least maybe the same noise. Mine starts at around 80mph and appears almost throttle dependant. If driving at over 80mph for longish distance the squeal seems to move up the speed range i.e. if I drive at 100+ for some while it will dissapear at 80 for a time. The noise appears to come from from the dash area (maybe) of course at 80+ it's a little difficult to place your ear near the sound. Does anyone have the definative answer to this annoyance? After doing a search at least I know I'm not alone.

 

Dear Laurence,
This is the world of Porsche there is no such thing as a definitive answer. In the UK I would certainly check the windshield. UK glass fitters do not follow Porsche installation procedures and glue it into position. If your glass is original then you look at the fresh air servo in your RS.
Ciao,
Adrian
964C4

 

Hi Adrian
By a stroke of bad luck my screen took a large stone chip and needs replacement. I have checked the screen and suprise it's NOT bonded in. So......... when the guys come to replace the screen I will make sure it's fitted properly (I am aware of the correct proceedure) . Will be interesting to see if this cures it!

 

Quick update. taken the car on couple of high ish speed runs after the new screen fit and no squeal yet. Yippee. will give it a while before I get too excited though.

 

The situation is pretty much the same here in the USA. I just had my windshield replaced two weeks ago and I had to fight the insurance company for OE glass and then I had to fight the installers (a Porsche dealership) to use the proper urethane adhesive and follow Porsche's instructions from the workshop manuals. My insurance company has a policy of only using OE glass on cars less than 2 years old. The aftermarket "SafeLite" glass is not glued in place, has an antenna that doesn't extend around the right side of the glass and has blue tint strip that does not fade but rather just abruptly ends. There is a TSB from April 2003 related to windshield installations that I haven't seen but I did know about and I told the Porsche dealership about (they had no clue). Once they looked at it they sent it over to the insurance company and the insurance company agreed to do the $1100 install and not the $385 aftermarket installation. I no longer have alldata so I have no idea what is in the TSB but if anyone does know could they please let me know?

 

Final update. 1500miles + now done , just been on holiday with the car. Trip included track day at Spa with about 200 track miles. German autobahn cruising at well over 100mph. No squeel what so ever. So if you suffer from this take a look at your windscreen (windschield) and see if it's bonded in place as it should be!