Re: Whine when decelerating

The first time I drove my 2006 Boxter with the top up I noticed a whine when decelerating and it almost goes away with the clutch in. As soon as you take the car off compression the sound disappears. Engine runs well, clutch is good and uses no oil at 80,000 Km's. Thanks, Mike

Love the response D but that doesn't resolve my concern.Mike

i'm sure a lot of people on this board would like to help you troubleshoot. I've got a few questions that could help start this process.

you wrote that the first time you drove with the top up. does this mean it's a new car to you, i.e. you just bought it? or does this mean you've had it since 2006 but never had the top up? (which would be amazing)

what exactly do you mean but taking the car off of compression? taking your foot off the gas?

there are a number of things that can whine. we should eliminate them one-by-one. throw-out bearing on the clutch. wheel bearings. various belt-driven accessories on the engine like alternator, water pump, power steering pump. etc.

give a bit more of an explanation of when the noise occurs.

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MY 2000 S, Ocean Blue, Metropol Blue, Savanah Beige.
Bought June 2000 - Sold May 2010

Just purchase the car this summer. Now that I know the noise is there I can hear it with the top down but faintly. With the top up the noise is quite noticeable when you take your foot off the gas and goes away as you accelerate. Coasting with the clutch in reduces most of the noise.
I don't hear any noises from the engine that would indicate belts or accessories nor do I hear wheel bearing type noise.
Also, changed the oil and the filter was clean.
Thanks for your help.
Mike

is the pitch or frequency of the whine the same at all RPM or does it vary with engine speed? i'm wondering if the frequency changes or just gets louder.
does the pitch or frequency vary with road speed, clutch in or out?

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MY 2000 S, Ocean Blue, Metropol Blue, Savanah Beige.
Bought June 2000 - Sold May 2010

"A mile of highway will take you one mile. A mile of runway will take you anywhere."

Thanks for the input. If it's differential related then not too much to worry about. I will change the transmission oil and make sure the grade is correct.

The noise is about the same at any speed over 20 MPH. When the clutch is disengaged the noise all but disappears. The noise can be heard in any gear but most noticeable in 5th gear over 50 MPH when the gas is off and the car is coasting. As soon as you press the gas pedal the noise goes away. Mike

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MY 2000 S, Ocean Blue, Metropol Blue, Savanah Beige.
Bought June 2000 - Sold May 2010

Is it a high pitched whine or more like a low howl?

• Throwout bearing?
• Low on gear oil, or wrong viscosity?

Quote
Laz
• Throwout bearing?
• Low on gear oil, or wrong viscosity?

You may be on the right track regarding the differential. I've had 4 cars over the years that have had a Ring/Pinion issues--for some reason--and the sound was always a high pitched whine on light throttle. Nothing on acceleration or deceleration.

this makes sense to me. differential would be car speed related rather than engine speed related and could very well be affected by power being sent to wheels or not.
granted that it's tough to diagnose on a forum, but it's probably the investigative path that i would go down.

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MY 2000 S, Ocean Blue, Metropol Blue, Savanah Beige.
Bought June 2000 - Sold May 2010

... for the dirt bikes?
Happy Boxstering,
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

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Racecar spelled backwards is Racecar

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