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Noisy PC with Vibrating Cooling Fan & Air Duct


Noisy PC with Vibrating Cooling Fan & Air Duct

I have PC that's getting to be annoyingly noisy. It's a Dell Dimension 4600 PC with a P4 CPU 3GHz and it's about 2 - 3 years old.

It has one main cooling fan that sucks air into the case from the back grill. The air is funnelled through a green plastic cowling or duct through the vanes of the CPU heat sink.

I'm guessing that the fan bearings have aged with wear and tear so it now vibrates. And the fan touches the air duct so vibration travels to the air duct which in turn resonates and generates the noise.

I've been looking at some of the fans you can buy from

Changing the fan looks possible but a bit fiddly : there are 4 rubber gromits that hold the fan to a base which in turn holds onto the case grill. I'm not sure how I'm going to deal with those gromits or if a new fan would have the right attachment points.

I may try padding the air duct though there's not much space and I'm not sure what material would be easy to work with. May be thin strips of sponge ?

Before I start buying components and ripping stuff apart, I was wondering if anyone else out there has had a similar problem ? Is 3 years the expected live span for a fan before it starts to vibrate ? And did a new fan bring about a significant noise reduction ?
Community Veteran
Posts: 1,229
Thanks: 1
Registered: 12-04-2007

Noisy PC with Vibrating Cooling Fan & Air Duct


I would bet that it is a standard fan (probably 92mm). Cost around 2 or 3 quid from a local PC shop. (Take the old one with you).
You shouldn't have to much trouble I don't think. Give it a go, worse case senario is that you break it.
In which case you could buy a full new unit - maybe here link

But considering the price they want for it, I would defo be having a go at putting a stock fan in the housing you allready have.

And yes fans can fail in a very short time indeed, depending on whether they get regularly cleaned or not. Dust builds up on fans real quick and throws them out of balance, which accelerates the wear tremendously.

Get yourself a can of compressed air when you buy your fan - to clean it and the rest of the insides of your pc from time to time. (especially the fins of your CPU heat sink).
Community Veteran
Posts: 14,469
Registered: 30-07-2007

Noisy PC with Vibrating Cooling Fan & Air Duct

It does sound like the bearing have gone/dried up.

As you need to get the fan out anyway try a tick I use which can extend the life for a while.

- Remove the fan
- Carefully peal back the label showing the make/model/voltage and any secondary cover (usually thin plastic). Don't remove it completely just enough to reveal the bearing underneath as you will be putting the label back.
- Put 1 or 2 small drops of oil on the bering and spin the fan a few times with your finger to get the oil into the bearing. Don't let any oil on the area where he label came from. I use normal household 3in1 oil but have also used cooking olive oil (has a higher temp threashold than normal oilve oil).
- Replace the label. If it fails to stick, put some sticky take on it or replace the whole pabel with sticky tape. Th ebearing needs to be covered.
- Briefly try the fan by reconnecting and switching your PC on. If the noise stops / decreases your in business.
- If ok, refit the fan

That may get you a few more months and give you time to find a replacement.