Intermittent buzzing behind dashboard?

[Pondy]

Hello peeps!

I have noticed a faint (electrical type) buzzing somewhere in the dashboard when the car is moving (doesn't do it when stationary). It is quite faint and you can't hear it when the radio is on. Comes and goes, but is there more often than not. It seems to be coming from somewhere around where the idrive screen would be, if I had one, which I haven't (I call it the sandwich holder). It sounds a bit like the heating matrix fan motor, but it can't be as if I turn the fan off it's still there and doesn't change pitch if the fan is increased or decreased.

It's starting to get on my t*ts. Any ideas as to what it could be?

 

[Chippie]

If it not there when stationary then I suspect it road vibration related, I find it very difficult to pinpoint noises in a car when driving, can you get a passenger to get their ear near where you think it’s coming from?

 

[srhutch]

Check the two braces where they meet the bulkhead, probably loose.

 

[blunderthumbs]

Have you checked your missus hasn't left her Rabbit in the glovebox

 

[Pondy]

Have you checked your missus hasn't left her Rabbit in the glovebox

She is scared of rabb......Oh I see. Filthy boy I've checked they are still in her bedside cabinet.

 

[Pondy]

Check the two braces where they meet the bulkhead, probably loose.

Thanks Mr Hutch, but it does sound electrical rather than mechanical. I'm wondering,is there is a solenoid for the heater matrix to meter the flow of water. That would make sense if there is.

 

[Smartbear]

Check the two braces where they meet the bulkhead, probably loose.

Thanks Mr Hutch, but it does sound electrical rather than mechanical. I'm wondering,is there is a solenoid for the heater matrix to meter the flow of water. That would make sense if there is.

If that was the cause you’d hear it with the car stationary as well i would have thought? :?
Rob

 

[parabolica]

Check the two braces where they meet the bulkhead, probably loose.

Thanks Mr Hutch, but it does sound electrical rather than mechanical. I'm wondering,is there is a solenoid for the heater matrix to meter the flow of water. That would make sense if there is.

I have something similar on cold days - it’s the metal casing of the radio/cd unit. It’s like the latchings holding the casing together are ever so slightly loose and it causes a buzzing noise until the car heats up. I was able to confirm it by taking out the vents the going for a drive and holding my hand on top of the cd/radio unit and the buzzing stopped. Nothing I could do to fix it - just one of those things.

 

[Pondy]

If that was the cause you’d hear it with the car stationary as well i would have thought? :?
Rob

Maybe so, but I haven't let it warm up enough stationary to shut the water supply off to the heater matrix.

Bearing in mind I have no climate control, the temp knob is hot or cooler, there must be some way that the water flow is regulated once the coolant is up to temperature? I am presuming there is a type of TMV (thermostatic metering valve), or even a solenoid to prevent the matrix overheating?

IE with climate control, the temp knobs ARE thermostats, which will meter some kind of valve in the matrix. Without CC there surely must be the same valve but is controlled by a non-adjustable thermostat set to a pre-set temp?? Does that make sense?