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Discussion Starter · #1 ·
What is that funny looking deflector that pops up when you open your sun roof for?

I always assumed that it was to smooth out air flow and reduce wind noise. However I pulled it down at highway speeds and the wind noise dropped a HUGE amount.

It did not seem to make any other difference to air flow in the car. Does any one know why Volvo has been using it for more then 30 years.

Was it necessary on the old "brick" body styles? Is it just a legacy symbol like the three engine cooling vents on Buick's?:)
 

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When I pull mine down it causes a big downforce of air into the car and lots of wind turbulance/noise.
 

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Discussion Starter · #3 ·
My car is a V50 and it is definitely better down then up with windows open or closed. Less noise and no wind. Any one with a V50 ever try this?
 

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The V50 has a downfall that the S40 only encounters when the back seats are folded down, and that's an uneven pressure in the cabin. If you hold the wind deflector down when the windows are up, at speeds over 45mph in an S40, you most definitely will hear that ear throbbing sound. So while it may add to the wind noise over the car, it prevents the air from entering the cabin at a weird angle. This means that it also prevents the girlfriend's hair from waving about wildly when the sunroof is open.

Really, you hit the nail on the head when you said it was a wind deflector. On the newer model P1s, they have ditched the plastic runner style and replaced it with a taller pieces of cloth material.

It's a pretty ingenious idea that many other car companies do now, it's a way to make having the sunroof open not feel like having the sun roof open, if that makes sense.
 

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Discussion Starter · #5 ·
Yes on my V50 I get a "Throbbing" sound if I open the rear windows but not the front. Or I get a "Ear buffering noise" if I open the fronts fully and not the rears. So I never open just 2 windows full at highway speeds. Partly open it is ok.

The sun roof seemed to make no difference to "these" problems last night but I am going to try different combinations over the next few days to see when the deflector makes a difference.
 

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my car has this problem too. when the deflector is up, the wind is terrible. but when i hold it down .. there nothing at all.

On the newer model P1s, they have ditched the plastic runner style and replaced it with a taller pieces of cloth material.

It's a pretty ingenious idea that many other car companies do now, it's a way to make having the sunroof open not feel like having the sun roof open, if that makes sense.
iv seen some cars with this peice of class... if only ours had it :(
 

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When I pull mine down it causes a big downforce of air into the car and lots of wind turbulance/noise.
In the old days...that's what an OPENED sunroof was supposed to be for!
 

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Discussion Starter · #8 ·
I think I know why there are different responses in this thread. The deflector noise seems to be speed dependent.

Below 70 mph my deflector creates just a small amout of wind noise when it is up but when it is down there is the loud throbbing noise.

Above 70 mph my deflectorctor creates a lot of wind noise which goes away when it is lowered. The throbbing noise seems to disappear at higher speeds even when down.

Idealy it should be on a servo and should drop at speeds above 70 mph. ;)
 

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I noticed the same thing that you did VictorVDC. I was cruising around 70 and the sunroof wind was drowning out music, so I started messing around. Pulled it down, and blammo, damn near zero noise. I never held it down long enough to see if there was and pressure issues.
 

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I never held it down long enough to see if there was and pressure issues.
You'd notice the pressure issue immediately. Sounds like we should tell Volvo to make an auto-lower sunroof deflector that lowers at 70mph!
 

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I noticed the same thing that you did VictorVDC. I was cruising around 70 and the sunroof wind was drowning out music, so I started messing around. Pulled it down, and blammo, damn near zero noise. I never held it down long enough to see if there was and pressure issues.
Lol, I always mess around with one hand and one foot at 70mph . . .
 

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