annoying whistle noise at 50mph+

[daniel7y]

Hi all

I've done a search and have found a few topics about a whistling noise on the freeway, but not quite specific to my issue. The noise seems to appear at about 50mph and it comes from the drivers side. Some observations:

- It's not the hole for the sensor in the mirror, I've tried covering it while driving but it's still there.
- When the window is all the way down the whistling noise seems to disappear (or it's just drowned out by the wind noise)
- The faster you go the louder it gets
- The windscreen seal has been replaced, but hasn't fixed the issue.
- When the heater or A/C is turned on, the noise decreases a little bit in pitch and volume. When you turn it off, it get's a bit louder and higher pitched.
- It's a dynamic noise and changes according to the wind (where a gust of wind will make it go louder and higher pitched)
- It's not the windscreen wipers because it doesn't change when they are operating.
- Sounds like it's coming from behind the dash.

Also, the car seems to fog up a bit too easily. There isn't any moisture (I've had to strip the interior and dry the foam and carpets due to a blocked scuttle drain), so I thought maybe there's a blockage somewhere not letting fresh air in, which might also cause the noise?

It sounds pretty pedantic, but it's very annoying. I hope I can locate the problem soon cos a fair bit of my commute is on the free way at 60mph, where it's loud and irritating.

Any ideas? Would appreciate any input. Would love to get this sorted.

Cheers

 

[daniel7y]

So I was driving at 70km today (43mph) with the window down half way and made a recording of the noise with my iphone. Thought it might help find the problem. The noise is actually pretty much always there unless your crawling around town. It just gets louder the faster your'e going.

https://docs.google.com/open?id=0B57M_ouzbAhVZmMyZFJUZUlmbzA

 

[Sash]

It might not be the hole in the mirror but the gap where it pivots I.e to push the mirror against the car.
Try changing the pollen filter on the car, that might help thr fogging issue.

 

[daniel7y]

I just got some masking tape so I'll do some experimenting with that. I'll give the mirror a go like you said Sash.

Can someone tell me how fresh air enters the cabin? Is the only way through the pollen filter?

 

[Sash]

Could be wrong but I think so, its also called a cabin filter... it sits between the fan motor and the air vents. Also if your vents don't blow much air bit the motor is running on full that can indicate a blocked filter - leaves, dirt etc.

 

[daniel7y]

Sorry to bump this thread again, but I'm getting desperate.

Using masking tape i have taped up the windscreen surround and the side mirror and I still had the whistle. All the rubber seals etc on the exterior of the car were taped down - any suspected causes. It's pretty much always there, even when travelling at 35-40mph. Does anyone have any ideas? It sounds like it's coming from behind the dash or at least on the drivers side somewhere.

How does fresh air enter the car? It goes through the cabin/pollen filter, but how does it get there first? I'm thinking it must be something under the bonnet.

 

[MarcB]

I have this slight whistle also when driving. Can only here it when the window is down.

I have NO idea what it is but i just turn the radio up louder

 

[Tony Hunter]

Does the noise change when you change the heater from recycle to fresh air ? If this is stuck on recycle it will also cause steaming up.

 

[Bluebeard]

Does the noise change when you change the heater from recycle to fresh air ? If this is stuck on recycle it will also cause steaming up.

This.

If the air cannot flow 'through' the car, it has to go somewhere and will cause a noise.

It could also explain the car fogging up as the air can't circulate.

What car is it?

 

[daniel7y]

Yeah after testing the noise changes according to the circulation on/off and the fan speed. I'm thinking it might be the valve(s) that close of the fresh air entering the cabin... maybe... Where should I look? Would it be under the scuttle panel, where the cabin filter is?

Thanks for the replies. I might be one step closer to eliminating this noise... it's driving me nuts...

.. oh and it's a 182

 

[cloud9376]

Is this the circulation button?

If so mine is stuck on and I get the same whistling noise!!!

 

[cloud9376]

Is this the the circulation button? If so mines stuck on and I get a whistling noise!!!

 

[daniel7y]

yeah thats the circulation button. mine has climate control but i'm assuming they work the same way. when you say stuck on, does the light not turn itself off when you push it?? i done some more research and apparently the flap gets stuck... it's located under the drivers side scuttle panel...

check here: http://www.cliosport.net/forum/showthread.php?554788-Air-recirculation/page2

daz182 explains how to get to it

i'm gonna have a proper look tomorrow and hope this is the problem. it was really windy yesterday and the noise was really intrusive, even with all the windows up.

 

[cloud9376]

Yeah that's the one the light never goes off lol so u reckon follow the guide and the light will go off or the button will function at least?

 

[cloud9376]

Nice one cheers mate ill have a look at the weekend whilst cleaning the egr

 

[daniel7y]

So, I think the problem is solved!

The recirculation button wasn't working and the flap was stuck half way. When you push the button it just kept clicking but not moving. I have pushed it open and the whistling noise is mostly gone. It is there but very faint - a noticeable improvement.

I'd like to get a greater understanding of the ventilation system of the car if anyone can help. As far as I see, the air passes through the cabin filter through to the blower which blows down into the drivers side footwell. This is where the circulation flap is.

What I don't understand is, where does the air come from that passes through the cabin filter?
I assume the air that comes from the heater and air con doesn't pass through any filters - just comes directly from the source (i.e. heater matrix?)
Does the fresh air only come through the cabin filter, which has the air circulation flap??
And finally, what is the big black box to the right of the cabin filter? THe blower and flap are to the left, but what is on the right?



Thanks to everyone for the help. The whistling noise was driving me insane. I'd really like to get a better understanding of the system, so if anyone has answers to the above I'd appreciate it!

 

[Feates172]

Id imagine its the mixer. As the resistor pack is located there.

May be wrong though.