Weird Noise from Behind the Dash - possibly air con related.

[Ronnie_Hotdogs]

Hi all.

Firstly, apologies if this has been covered elsewhere - I had a quick search and found some similar posts, but nothing quite the same so thought I'd try my luck.

 

My Mk.3 vRS has a strange intermittent noise coming from somewhere in the dash, around the steering wheel and cluster. I'd describe it as sounding almost exactly like a computer hard drive working away processing something.

Sometimes it can disappear for days, even weeks, so it has been quite hard to track down. All I can tell so far is:

 

• It doesn't seem to be a vibration - in that it isn't related to revs, road surface, speed etc.
• It will do it when driving or idling and even when the auto stop-start cuts the engine.
• One possible clue - I managed to catch it this morning when the auto stop-start cut the engine in my driveway, so I played around with a few things, switching them on and off to see if it made a difference and when I switched the air-con/fan off the noise suddenly stopped. I can't be totally sure this is the cause though as it didn't resume again when I switched it all back on.

 

I've seen posts about air-con noises making a sound like a cricket, but this sounds completely different.

 

Cheers!

[aki78]

The moment when my left temperature motor failed in my previous MY14 O3: https://youtu.be/Y3dvCeBMlmQ

It fell apart. I tried to put it together and it kind of worked again but with weird noises and very instable temperature in the cabin. These are the last days of the motor before replacing: https://youtu.be/6xnnS4cANSk

You can hear the abnormal noise from 0:45.

 

By the way sometimes I can hear similar 'HDD noise' in my current MY19 when waiting at the red light and not listening music. It's very quiet, but yeah, when I turn the A/C off it disappears.

[Chathura]

On 18/01/2023 at 22:52, Ronnie_Hotdogs said:

Hi all.

Firstly, apologies if this has been covered elsewhere - I had a quick search and found some similar posts, but nothing quite the same so thought I'd try my luck.

 

My Mk.3 vRS has a strange intermittent noise coming from somewhere in the dash, around the steering wheel and cluster. I'd describe it as sounding almost exactly like a computer hard drive working away processing something.

Sometimes it can disappear for days, even weeks, so it has been quite hard to track down. All I can tell so far is:

 

• It doesn't seem to be a vibration - in that it isn't related to revs, road surface, speed etc.
• It will do it when driving or idling and even when the auto stop-start cuts the engine.
• One possible clue - I managed to catch it this morning when the auto stop-start cut the engine in my driveway, so I played around with a few things, switching them on and off to see if it made a difference and when I switched the air-con/fan off the noise suddenly stopped. I can't be totally sure this is the cause though as it didn't resume again when I switched it all back on.

 

I've seen posts about air-con noises making a sound like a cricket, but this sounds completely different.

 

Cheers!

 

Does it sound like an old computer hard disk or "water flowing" through a pipe?

 

I also kept looking for advice as I had been having a "water flowing" noise when the engine stops. The coolant system had been recently checked by qualified mechanics as there were some air pockets after the timing belt + water pump change, and then the car was serviced twice after that. Therefore, I didn't have a reason to worry before. 

 

The recent observations:

I had also noticed that the A/C vents in the driver side were blowing only cold air. Initially, I thought that it would be normal have cold air flowing through the A/C vents in a winter weather like that. But once on a freezing cold day during this winter, after driving about 30 mins, I also heard a noise under the glove box exactly like a little bird (2, 3 times and it stopped) as I remember it (someone can actually say that's the noise of a cricket). That's when I started to worry about this.

 

What fixed it:

Then I had the expansion tank open and kept the engine running for a while. Because, I thought the very first thing to do is to get rid of any remaining air pockets in the system. After the timing belt change, the staff at the garage had filled coolant up to the (minimum) level it barely touches the sensor, in order to make sure that there are no leaks or coolant loss. After that, I also didn't bother to fill coolant to max level or in between. So, I filled some more coolant mixed with de-ionised water and kept the engine running. I didn't observe any progress immediately, but after one shopping trips, the driver side heating started to work as normal. 

 

As precautionary measures:

• I checked if my car has that "silica get packet" in the coolant expansion tank as many people in the Briskoda forum had warned that it is prone to break and clog the coolant system (especially, heater core). But that silica get packet wasn't there in the coolant expansion tank. I believe the staff members of the garage probably have removed it already. 
• When I checked the colour of the coolant in the expansion tank, I thought it would be better to get the system flushed and refilled. I know that this is something I could have done by myself, but I booked a mobile mechanic via ClickMechanic for £108 as I would hardly find time to shop all the necessary equipment and to do the job. Since the weather is too cold this week (even running in to minus degrees), the job was postponed.
  • The reason: They have to drain the old coolant and put the cleaner (something like Prestone) and run the engine and then run de-ionised cold water twice before refilling the system with new coolant. Having to put cold water in this freezing weather to a warm engine can do damage in theory. Therefore, we are waiting until the next week for this.
• I am about to change the pollen filter also as my car was mostly parked near our house that was being renovated before the winter (lots of dust and particles of sanded walls and cut floorboards)

 

 

Edited 20 January, 2023 by Chathura
amendments required