Fan Noise

[Doug the bug]

Hello forum,
I tried a feww searches but didn't find anything on this: My ventilation fan hums a bit in 1st and second speed position I can make it louder by pressing the brake pedal and I can make it go away by turning it off. It is preety cold today -20*C. It just started this today. Has anyone encountered this annoying tune?
Doug

 

[Ric Woodruff]

I don't know what the brake pedal would have to do with it, but such noise usually means that the fan blades are caked with dirt and dust. You have to remove the fan and scrap off the dirt with a screwdriver blade.

I have cleaned several fans, and have been successful at eliminating noise as you described. Not only will you end the noise, but your fan will blow air much more efficiently, besides.

Note: On some vehicles your remove the fan from under the hood, and others you remove from under the dash.

------------------
Ric Woodruff

I'm not cheap... I just
know a good bargain
when I see one!


1998 Jetta TDI Custom Sport

[This message has been edited by Ric Woodruff (edited December 07, 2000).]

 

[Karl Roenick]

What would the symptoms be for a clogged pollen filter?

 

[GeWilli]

mine makes a hum in the 2nd position only when it is cold out. and it goes away after the car warms up. But then driving for an hour does actually seem to warm everything up. With a short commute (less than 20 miles) it might not warm up enough to go away.

I have not seen a coorelation ot the brake pedal though.

I just chalk it up to the idiosyncracies of this german engineering

 

[Doug the bug]

Thanks Ric
I'll give it a scrape if I find it. Anyone know where it is on a '00 Jetta?

 

[Doug the bug]

The noise actually appeared after about 45 minutes highway and lingered the remaining 15 minutes in.

 

[Doug the bug]

Just wanted to see what new signature looks like

 

[dieseldorf]

I think I hear this noise as well in my '00 Jetta but it only seems to be noticeable when it is quite cold. It is sort of a low frequency "moaning"...almost like a vacuum cleaner running far away!?!?

I don't think its a dirty fan blade or pugged pollen filter. The car has only 4k miles on it.

I don't seem to hear it in the summer but since the weather has turned colder here, I am hearing it again. It does seem to disappear after the car has been driven for a while.

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96 TDI Wagon, ABS, emerald green
00 Jetta TDI GLS, silver arrow, CWP, LUX1, etc, etc.

[This message has been edited by dieseldorf (edited December 07, 2000).]

 

[Karl Roenick]

Does it matter what configuration the heater controls are in (def, heat, etc)

 

[Doug the bug]

Does not matter....didn't try the airconditioning.

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2000 Jetta TDI
Cool White with Road Salt Hi-lites

 

[DeafBug]

Mine is bit different. It is quiet on 1st and 2nd setting. Quite loud on 3rd and 4th. Related to brake? No.

 

[Vin]

Mine does it on 1st + Heat all the way up. That's all. Any other configuration will make not make the noise. 2001/Jetta

 

[WNY PAT]

YES, YES, YES... I love this forum. I was just about to post on this topic.... here are my symptoms:

Sounds like a little bird in the dash: chirp, chirp, chirp. I hear it when set to "1" and it is cold outside (25 F or so it seems). Just started the other day so I have't had a chance to really try out much and isolate when exactly it happens (brake pedal, temperature outside, climate control settings, etc.). I'll try to do a little detective work tonight and see if the same things are happening with mine too. My first thought, however, was that it was some kind of bearing in the fan motor.....

 

[dieseldorf]

WNY PAT, i used to have a chirping fan as well. It was a tired fan motor bearing.

I don't know what the vintage is of your car but the vehicle that I had with the same condition was about 12 years old.

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96 TDI Wagon, ABS, emerald green
00 Jetta TDI GLS, silver arrow, CWP, LUX1, etc, etc.

 

[WNY PAT]

Mine is a 2K Jetta TDI GLS. I'm curious to see if anyone else has experienced the same problem... it really does seem to be the motor.....

 

[TDI-Dave]

I've got the same problem. First setting, there's a constant high pitched noise going when the car is cold. After it warms up, the problem seems to go away.

I'm not the only one -- I have a coworker with a 2000 Jetta, and his does the same thing.

I guess it's just a problem with the engineering.



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2001 Galactic Blue Jetta TDI
5 Speed - Black Velour Interior
Luxury & Cold Weather Packages
No Extras - The Car Is Perfect

 

[dieseldorf]

it "sounds" like this malady affects many of us, if not all of us. Perhaps the great thinkers at VWoA will be issuing a TSB soon and buying all of us new fans!??!

I don't think it annoys me enough to let them start ripping my car apart though.

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96 TDI Wagon, ABS, emerald green
00 Jetta TDI GLS, silver arrow, CWP, LUX1, etc, etc.

 

[Robert P]

Been driving my 2000 Jetta GLS with 16K on it for a week now and my fan motor is quiet in all 4 positions. I did have that noise in one of my previous Chevy's. Sometimes it was leaves or other garbage that got into the fan somehow. Noise seemed to come and go. I'd turn the fan to high / Low several times and the fan would settle down. It could run like that for quite awhile. If it gets too annoying get it checked under warranty if you trust your dealer. I know my dealer in Winnipeg seems to be a top notch dealership. Don't think I'll have too much trouble trusting them until the warranty is up.

 

[WNY PAT]

OK.. this is strange.... or maybe not that strange....

I noticed the noise tonight.. decided to take a few minutes and check things out:

Brake Pedal: no effect

Fan Speed: no effect!?!?!

Open Glove Box Door, put a little pressure on hinges: no noise

New theory: maybe the TSB for glove box rattle / squeak will cure this... the noise did not change with the fan motor speed... same at 1, 2, 3, 4... seemingly ruling out bearing in motor (although I hope someone with more expertise than me about these sorts of things can confirm this). Maybe when the car is cold there is more "play" in the plastic glove box components. When the car heats up the plastic expands and the noise goes away. I have an appointment to have the glove box fix done on 12/23... will post an update if this hasn't been solved yet....

BTW... mine definately doesn't hum.... that sounds like a different issue....

 

[tonsofun]

It’s a ventilation fan. On my ‘99Golf the noise was so annoying that I had to turn the ventilation off from time to time (no fun when it’s really cold!), especially when driving with a passenger. On my ’00Jetta this high-pitched hum is also clearly noticeable, although not as bad as on the Golf. The problem begins when it’s –5C or colder. I don’t know what the remedy would be.

-Vic

 

[saintex]

Same problem for me, in cold weather the fan has a high pitched hum in low position that almost disappears in position 2 and is not noticeable at higher positions. It does'nt make noise in warm weather. 2K Jetta

PS its going down to -30 deg C tonight

 

[**DONOTDELETE**]

Doug the bug I have the same noise. It started before the pollen filter was changed and is still there after it was changed. Only noticed this noise when it started to get cold out. First fan speed only and it will go away if I turn the temp knob all the way to cold.

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2000 JETTA TDI GLS 5speed

 

[T5TDI]

I'm not sure if this is any help but older worn heater motors can make an "impossible to ignore" high pitched squealing noise. Sometimes you can cure this by switching the fan to a higher speed. This noise is caused by a graphite impregnated bush (bushing in the US) at one end of the motor "drying out". Some heater motors have a rubber plug that you can remove and apply your choice of lubrication. You would be unlikey to hear this fault on a VW less than 5 years old.

You may have heard starter motors on older cars making an odd squawking noise after the key has been released, this is also caused by a similar rear starter bush failure.


Karl,

The symptoms of a completely blocked pollen filter are mainly just a restriction of the airflow from the heater. It's supposed to be bad news microbe-wise too.

[This message has been edited by Brodie (edited December 09, 2000).]

[This message has been edited by Brodie (edited December 09, 2000).]

 

[VeeDubTDI]

I don't think it's the fan motor at all. I think it's the air flowing through the ducts. The reason why I think this is because many have mentioned hearing the noise when the heat knob is set on hot. Turning the heat knob changes the airflow characteristics in the heater coil. Just a thought.

My NB makes the same noise when it's cold out w/ the temp knob on hot and the fan on #1. Sometimes with the fan on #2.

I've also noticed that my fresh air flap (recirculation switch) creaks/squeeks when I push the recirculate button.

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2000 Yellow New Beetle 1.9 TDI 5-speed
1987 Diamond Blue Mercedes-Benz 190D 2.5 Turbo (sold, but considering re-purchase)

 

[dieseldorf]

I am wondering if VeeDubTDI doesn't have a valid point. My car makes sort of a distant moaning noise (like a vacuum cleaner far away) and it seems to be a function of air flow and cold air temp. It does not sound like the fan itself. My car only does it when the ambient air is cold.

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96 TDI Wagon, ABS, emerald green
00 Jetta TDI GLS, silver arrow, CWP, LUX1, etc, etc.

 

[POM]

I've just started to notice this. But it's "dangerously" cold here (-15 F). Does it starting at about 0 degrees. But everything is creaking. Rattles in the back, rattles in the dash, but I'm quite happy that it starts, runs just fine, heats up, and eventually as the car warms, most of the rattles go away; and on warmer days it doesn't make all that racket. I'm just chalking it up to the cold weather.

 

[Turbo Steve]

A-4 Cabin Air Pollen Filters: http://forums.tdiclub.com/NonCGI/Forum7/HTML/000491.html

 

[Tinker]

There is a little birdie stuck in my vent system aswell. He chirps on the #1 and 2 positions and sometimes in #3. It gets worse when going over bumps and when turning to the right. I think it has to do with the fan (bearings) because when the car is turning there the fan could react to the centifugal force being put on it. I have heard similar noises with computer fans and after adding oil to the bearings it goes away. Next warm day or if I can find a heated garage I will investigate.

 

[Brat]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by WNY PAT:
Sounds like a little bird in the dash: chirp, chirp, chirp. I hear it when set to "1" and it is cold outside (25 F or so it seems).<HR></BLOCKQUOTE>

My theory is that it's plastic parts rubbing inside the ventilation system; at a certain temperature the parts are just close enough to do this. Too cold, and they're too far apart, to warm, they're snug.


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Green/Beige Y2K Jetta TDI
Wende dich ans Übele: Fahre Diesel!

 

[Canadies]

I've had the same annoying heater fan noise like a moaning sound during cold weather operation.
I only decided today to search the forums for a thread to discover yours.

Was wondering if you had figured out the problem.

I notice the moaning can be over all of the fan speeds during cold start -up, then diminishing only to level 3 and 4 once there is heat in the system.

I also notice the braking effect, only when driving, as if the momentum change re-aligns or corrects something. There is a similar effect when the car encounters potholes or abrupt bumps which randomly stops and sometimes retriggers the noise.

At first I suspected poor fan motor bearings, then re-thought this since the pitch of the moaning does not vary with fan speed.

Anyways, I have the Bentley repair manual and will start some investigating.

Canadies
Hamilton