Afternoon all,

I've only had my car around 3 weeks and all has been great so far, until last night.

I got in the car to drive home and when turning the air con down as the fans started to increase in speed there was a vibration noise that quickly got louder with each increase in speed of the fan, at flat out the noise is loud enough to hear from outside the car and is just like a deep vibration sort of sound, almost like if something is unbalanced,

I've searched the forum and all I can find are Air con related threads but this is more the physical fan / blower from what I can tell.

 

Is it possible that a blade could have broken off or something like that? 

Yep, thats exactly what it sounds like, or a piece has broken off. Or a slug is attached to it

Had a similar problem last week with a Mazda. Removed the fan; two small leaves had found their way into the middle of the fan impeller (fan is almost identical to a Skoda one). Removed leaves - problem gone.  Really surprised at how much noise they made, and just as your description.

 

Haven't removed the fan on an Octavia, but have on a Superb, which I think uses the same heater box. It was pretty easy, as long as you don't mind laying on your back over the passenger door sill. It sits behind the glovebox. The power connector has two small 'wings', one at each end, which need squeezing to release it. Then, the motor rotates about 1/8 of a turn after a plastic tang has been lifted/disengaged. The motor drops down, provided the carpet/wiring loom/soundproofing isn't too close.

 

It's probably more fiddly to get back in. The locking tang slides up a ramp on the plastic housing, (on the casing that stays with the car), as the motor is twisted in the opposite direction.

Edited 8 July, 201411 yr by CombatWombat

Thanks guys, my mate popped up last night (he's an all round Car audio / mechanic / interior re-trimmer etc) and has way more experience with taking things apart like this, within 5 mins he had the glovebox out and with the air con running as the flap lifted up he could see something in the fan, as it slowed down it was definitely white.  He turned the car off, managed to get his hand in there and pull out a Car park ticket from 2013 (prev owner) so I guess it must have slipped down the back of the windscreen or something :-)

I was just so pleased this was all that was wrong, I am pretty sure most garages would have probably just changed the fan without even checking so it has potentially saved me a fortune!

 

Thanks again!

had exactly the same thing on mine.. how on earth it gets in there i don't know!