uchu47

Noticed a strange sound coming from somewhere near glovebox... Hard to describe, but something like thin paper touching fan, like whispering? Reasonably quiet, can't hear while listening loud music, but otherwise quite annoying.

Not correlated with road smoothness or engine rpm, but does appear only above somewhere 50km/h. No correlation with speed either.

Giving the sound I suspected blower first, tuned off A/C - sound still there, suspected command fan, turned off command - still there.

Needless to say, checked/removed everything from glovebox that can produce any sound.

Going to mechanic is likely not good idea now since sound is reasonably quiet and barely can be heard in city centre.

Any ideas what can it be? Sorry for vague description.

TimC300

I do know sounds travel and can be hard to locate. I was driving and heard a sound that I thought may be coming from the front drivers side strut, for some reason I decided to push the glove box door in hard and the noise went away. Shows I was way off in my original thought.

To really rule out the blower motor have the car running with the heat on then open the hood and remove the plastic box above the battery, you should be able to see the blower motor and hear if any noise is coming from it.

JettaRed

iTrader: (1)

I hear the same thing occasionally in my C-Class. Sounds like a bad fan bearing or a leaf got sucked in.

uchu47

Yea, that's exactly how it sounds. Blower bearing you suggest?

uchu47

Absolutely agree. Unfortunately I can't run the car with heat on - likely there is no heater physically as the car is for tropics (Thailand). This also means A/C has been used heavily (so looking at blower).

Turning A/C off allegedly turns off the blower (if ECU doesn't keep it running for residual cold) but the noise still stays.

JettaRed

iTrader: (1)

My noise is occasional and will go away. So, if it is the motor, mine may not be as bad as yours.

wow! You really have no heat function? That makes logical sense, but not logistical sense to me. But I’m not Mercedes.

Tim’s recommendation still holds, however.

JettaRed

iTrader: (1)

Turning off the A/C should only affect the compressor noise. You should still be able to run the blower.

uchu47

I really don't know lol, perhaps it does have - but at outside temperatures ranging 30-40 degrees Celsius through the year it's a bit difficult to test if it actually has it

For the same reason I have different A/C package compared to say european cars. It is called something like strong A/C. Makes huge difference in tropics compared to europe - imported cars

uchu47

In my case pressing OFF at A/C panel turns off all lights and air stops blowing completely. I assume it does stop the blower?

JettaRed

iTrader: (1)

There should be both an A/C button and an OFF button. Use the A/C button to turn off the compressor.

uchu47

My sound starts to show itself at speeds above 40km/h, so i can't really test it this way... Staring to think it's actually a leaf under hood somehwere

Just204

Have someone ride in the car with you, take a silicone or other flexible hose/tube and when you start hearing the noise put one end to your ear and move the other end around the area you think it is and if you hear it through the hose that is approximately where it is. It’s basically a poor man’s stephoscope. Good luck.

uchu47

Sorted out finally - it was a crappy bolt underneath the car. Sounds really make weird ways inside our cars.